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1: Tubes Asylum, RE: Is there a 6SL7, 7193 type tube that anyone knows about? (0.00)
Posted by maxhifi on 2024-01-09, 07:31:50 (162.157.138.86)
I'd say the 6F5 is as close as you will get .......
2: Tubes Asylum, RE: New KT150, maybe? (0.00)
Posted by maxhifi on 2024-01-08, 09:25:36 (165.225.210.181)
If this tube can actually reliably handle the high voltages the Russian tube is designed for, it will be a godsend to amp owners looking for an alternative. I also kind of like how it looks more like .......
3: Planar Speaker Asylum, RE: Eminent Tech. is now selling the LFT-8C, with powered bass module (0.00)
Posted by maxhifi on 2024-01-07, 21:52:53 (162.157.138.86)
I was a bit confused by the pic until I read 2005... haven't seen Ei tubes and VHS tapes in a while! .......
4: Planar Speaker Asylum, RE: Maybe its the color. (0.00)
Posted by maxhifi on 2024-01-07, 21:30:20 (162.157.138.86)
If they showed up here for 350, I think I'd accept avocado green with a fake woodgrain stand. Seriously that's a really good deal! .......
5: Planar Speaker Asylum, RE: Looking for magnepan ribbon tweeter repair instructions (0.00)
Posted by maxhifi on 2024-01-05, 16:16:43 (162.157.138.86)
Would be much appreciated! My email should be visible to members .......
6: Planar Speaker Asylum, Looking for magnepan ribbon tweeter repair instructions (0.00)
Posted by maxhifi on 2024-01-05, 13:18:11 (162.157.138.86)
I've managed to find a tweeter rebuild kit missing the instructions for my iiia. Anyone happen to have a copy? .......
7: Tube DIY Asylum, KT88 (0.00)
Posted by maxhifi on 2023-03-15, 18:56:39 (165.225.210.174)
I can make my own generalizations. EL34 - Wonderful sweet sound at low to medium volume, but runs out of power with difficult speakers or high volume levels unless used in multiple pairs. KT-88 - Be .......
8: Tubes Asylum, RE: Another fake tube to smash ~pics~ (0.00)
Posted by maxhifi on 2023-01-10, 08:56:46 (209.107.108.252)
That tube looks like it was relabeled by RCA itself, most likely in the 1970s. It is quite common to find all manner of foreign tubes with RCA labels, and incorrect country of origin, from the late tu .......
9: Tubes Asylum, RE: Japanese tubes, especially the EL34 made with Mullard tooling. IS there. . (0.00)
Posted by maxhifi on 2022-12-18, 10:09:28 (209.107.108.252)
Wow, those are some rare tubes! .......
10: Tubes Asylum, RE: Do these look like real GEC KT88 tubes? (0.00)
Posted by maxhifi on 2022-12-17, 19:42:04 (209.107.108.252)
Shape of glass envelope also looks wrong. .......
11: Planar Speaker Asylum, RE: Is it normal for Magnepan LRS speakers to distort at high volume? (0.00)
Posted by maxhifi on 2022-08-11, 12:17:03 (173.183.234.73)
This is exactly what I was thinking. Subsonic noise. If you can substitute in a pair of normal speakers, check to see if the cones are moving excessively. If yes then it is subsonic. .......
12: Tubes Asylum, RE: Repairing damaged trace on circuit board (0.00)
Posted by maxhifi on 2022-08-10, 20:14:34 (24.244.29.56)
Post a photo of the damage. This is not likely a big deal. .......
13: Tubes Asylum, RE: Mullard CV2493 in Audible Illusions preamp (0.00)
Posted by maxhifi on 2021-12-22, 20:54:21 (50.99.245.186)
What rectifiers are those? Look like tv damper diodes to me... cool.. I built an amp with a pair of 19AU4 as rectifiers in 1998 and they're still going strong. Anyway nice amp! .......
14: Tubes Asylum, Don't go looking for problems (0.00)
Posted by maxhifi on 2021-12-06, 21:10:40 (208.98.223.45)
If the bias varies plus or minus 10-20% over the course of a day, it won't really affect how the amplifier sounds, provided that all tubes vary equally, which they will unless something is defective. .......
15: Tubes Asylum, RE: Issue with tube bias drift in my integrated amplifier! (0.00)
Posted by maxhifi on 2021-12-05, 14:53:56 (199.119.235.153)
I suspect the AC line voltage is fluctuating and causing bias to drift. Not a lot you can do about it, but try and measure it to confirm. .......
16: SET Asylum, RE: 2a3 and 6B4G amps and tubes - favourites? (0.00)
Posted by maxhifi on 2021-11-26, 10:22:41 (137.186.156.146)
I actually haven't met a 2A3 I didn't like, from the cheap Chinese bi-plates of the 90s, to NOS Westinghouse or RCA tubes, to the JJ 2A3-40s which at the time I bought them were the most expensive pai .......
17: Tubes Asylum, RE: I went to the source... (0.00)
Posted by maxhifi on 2021-11-18, 09:33:23 (137.186.156.146)
Diodes? .......
18: Tubes Asylum, RE: stupid question / 6SJ7 replacement? (0.00)
Posted by maxhifi on 2021-11-15, 18:27:01 (199.119.235.143)
6SJ7GT .......
19: Tubes Asylum, RE: 6X4 (0.00)
Posted by maxhifi on 2021-10-20, 12:49:47 (137.186.156.146)
The 6X5 was famous for shorting out and ruining radio power transformers. The only one of this type I trust is the 6CA4. .......
20: Tubes Asylum, RE: 300B were made through the 80s for AT&T... (0.00)
Posted by maxhifi on 2021-10-14, 13:41:01 (137.186.156.146)
2A3 was made in massive quantities for replacements in radios and amplifiers, probably also some military use. Still fairly easy to find on the used or NOS market. Those vintage UK tubes you're talki .......
21: Tubes Asylum, Which spec is better n the PX25 than the 300B? (0.00)
Posted by maxhifi on 2021-10-14, 10:15:22 (137.186.156.146)
Going over the data sheet, the 300B has higher ratings, and comparable linearity. Plus it doesn't have the hard to find socket. And, the 300B didn't die out because it continued to be made through the .......
22: Vinyl Asylum, Just be sure you can't catch the stylus on whatever you cover it with (0.00)
Posted by maxhifi on 2021-10-12, 20:42:54 (137.186.156.146)
I like the put a cardboard box over it idea. .......
23: Tubes Asylum, RE: Who uses European tubes? (0.00)
Posted by maxhifi on 2021-10-05, 13:52:07 (137.186.156.146)
To be fair, the KT88 and EL34 and EL84 are all not originally American tubes despite the socket compatibility, and together probably represent the majority of power tubes used in new amplifiers. That .......
24: High Efficiency Speaker Asylum, RE: Stoopid question. I know, but... (0.00)
Posted by maxhifi on 2021-09-28, 07:19:46 (137.186.156.146)
I'm not entirely sure you can make those blend in, pretty much no matter what you do. I'd probably try and suggest to do something she likes doing, but you don't as a bit of compensation. Maybe take .......
25: Tubes Asylum, RE: That would have been illegal (0.00)
Posted by maxhifi on 2021-09-16, 11:34:59 (137.186.156.146)
I've seen it time and time again, including with BRIMAR, lots of Soviet made EF86, 6P3 labeled as 6L6GC, 6P6 labeled as 6V6GE England. I even have an Amperex 6V6 which is very clearly of Soviet origin .......
26: Tubes Asylum, Misplaced worry (0.00)
Posted by maxhifi on 2021-07-29, 06:03:30 (50.99.247.79)
Finger prints look ugly, but vacuum tubes used in audio amps quite simply don't get hot enough for the finger oils to be to be an operational issue. You have to look no further than typical modes of f .......
27: Tubes Asylum, DATA (0.00)
Posted by maxhifi on 2021-07-16, 08:49:39 (50.99.247.79)
The data sheet isn't in english, but you can draw your own conclusions... this is a VERY robust tube, way more so than the EL34 Check that out, 130W from a pair with 700V on the plates! Wow. ::: T .......
28: Tubes Asylum, RE: 12AU7 Reviled (0.00)
Posted by maxhifi on 2021-07-02, 07:33:56 (50.99.247.79)
Because in real world applications it can work well and sound good. Plus, it is cheap and easy to buy because several companies still make it, so it is a sustainable choice for new designs. Even with .......
29: Tubes Asylum, RE: Setting for Testing 300A on TV-7 D/U? (0.00)
Posted by maxhifi on 2021-06-12, 07:47:58 (50.99.247.79)
I thought the only difference between the 300A and the 300B was the locator pin location. They should use the same settings in the TV7 because it does not use a socket which is affected by the locator .......
30: Tubes Asylum, RE: interpret plate current measurement (0.00)
Posted by maxhifi on 2021-05-15, 22:58:07 (75.152.195.50)
I have replaced many output tubes like that, which bias fine and "work", but cut the power output of the amplifier in half or even less because they are used up. If you're okay with that, that's alri .......
31: Tubes Asylum, RE: Any reputable sources for Type 45 tubes? (0.00)
Posted by maxhifi on 2021-05-06, 09:36:44 (75.152.195.50)
A local antique radio club may lead you to someone nearby who can sell you tested tubes. The 45 has not been made in quantity in 70 years, so keep in mind you're buying a somewhat rare antique, and no .......
32: Tubes Asylum, RE: Tube Inflation since 1965 ? ........................ (0.00)
Posted by maxhifi on 2021-04-29, 07:51:20 (75.152.195.50)
The 300B was about $9.50 in the mid 1950s, which was very expensive, but it was a special tube designed for commercial or industrial use, not something employed in consumer applications. .......
33: Tubes Asylum, RE: Cleaning up Old Vacuum Tubes - Base and Glass.......... (0.00)
Posted by maxhifi on 2021-04-19, 21:44:58 (75.152.195.50)
I polish the dirt off with a dry paper towel or cloth. For the nasty baked on stuff there's always dish soap but it will wash most graphics off except sandblasted or etched tube numbers .......
34: Amp/Preamp Asylum, RE: NAD C370 - help with repair (0.00)
Posted by maxhifi on 2021-04-19, 17:07:34 (75.152.195.50)
I suspect either bad/intermittent contacts in the protect relay, bad/intermittent contacts in a selector switch, or a weak electrolytic capacitor somewhere which is affected by temperature. Output tr .......
35: Tubes Asylum, RE: Rots o' Ruck Rorge selling @that $$ nt (0.00)
Posted by maxhifi on 2021-03-26, 15:04:01 (199.7.159.62)
Uh dude it's Astro the dog, from the Jetsons... maybe you're hearing it different tly than I am but nothing racial just a silly dog voice! .......
36: Tubes Asylum, Exactly! (0.00)
Posted by maxhifi on 2021-03-22, 11:17:23 (75.152.195.50)
That ad is complete BS .......
37: Tubes Asylum, RE: 6bk11 tube alternatives? (0.00)
Posted by maxhifi on 2021-03-17, 16:14:23 (75.152.195.50)
The letters in the tube number represent the unique part number assigned to that particular tube type. A 12 pin tube is called a compactron, and you may find a substitute, but you're probably best off .......
38: Tubes Asylum, Philips capacitors? (0.00)
Posted by maxhifi on 2021-03-12, 06:01:57 (75.152.195.50)
When was the last time Philips made capacitors? I thought they sold that division years ago. Strange to see them in a new product. .......
39: Tubes Asylum, Check your tubes against this drawing from the WE Data (0.00)
Posted by maxhifi on 2021-03-09, 07:44:29 (75.152.195.50)
IMO measure the pins of the new tubes, and compare them to the spec for the 300B. If your new tube doesn't match the spec, then don't use them. If they do, then replace the sockets. Something is wr .......
40: Tubes Asylum, RE: Best new tube for ARC Classic 150? (0.00)
Posted by maxhifi on 2021-03-04, 12:24:51 (75.152.195.50)
Thanks for this! .......
41: Tubes Asylum, RE: Best new tube for ARC Classic 150? (0.00)
Posted by maxhifi on 2021-03-04, 07:03:59 (75.152.195.50)
This is great info, it seems like there are several choices here. Have you got any thoughts about the Tung-Sol 6550 in ARC gear? .......
42: Tubes Asylum, RE: Best new tube for ARC Classic 150? (0.00)
Posted by maxhifi on 2021-03-03, 13:32:55 (75.152.195.50)
So you vote EH KT88 - that's interesting! .......
43: Tubes Asylum, RE: Best new tube for ARC Classic 150? (0.00)
Posted by maxhifi on 2021-03-03, 10:29:56 (75.152.195.50)
Hi Jim, Thanks for your reply! Which tube would you suggest for the Classic 150? .......
44: Tubes Asylum, RE: FWIW (0.00)
Posted by maxhifi on 2021-03-03, 06:10:49 (208.98.223.96)
Cool, they're a little cheaper too. Mind you I just spent the evening listening to a 300B SET amplifier with my speakers, and didn't once run out of power. So I am not entirely sure why I'm so worrie .......
45: Tubes Asylum, RE: FWIW (0.00)
Posted by maxhifi on 2021-03-02, 18:28:34 (208.98.223.96)
How long have you had the EHX tubes for? .......
46: Vinyl Asylum, RE: Brand new Technics SL-1210GR platter wobble ... disappointed! (0.00)
Posted by maxhifi on 2021-03-02, 08:12:53 (75.152.195.50)
If you are absolutely 100% sure that the platter is seated properly (take it off, make sure everything is clean, and then carefully put it back on and press firmly around the spindle), then this is an .......
47: Tubes Asylum, RE: Best new tube for ARC Classic 150? (0.00)
Posted by maxhifi on 2021-03-02, 07:48:46 (75.152.195.50)
If I could get SED 6550C at the prices they sold for 20 years ago, I'd be all over it. I've ruled out using JJ or Chinese tubes on the basis of reliability. NOS tubes like GE are not realistic to obt .......
48: Tubes Asylum, RE: Best new tube for ARC Classic 150? (0.00)
Posted by maxhifi on 2021-03-02, 07:13:34 (75.152.195.50)
ARC changed from supplying the amplifier with 6550s to KT88s mid way through production, and Stereophile did a review about it, which seemed to favor the KT88. I was thinking to install 6550s, becaus .......
49: Tubes Asylum, RE: Best new tube for ARC Classic 150? (0.00)
Posted by maxhifi on 2021-03-01, 18:45:03 (75.152.195.50)
That's two for staying with the gold lions! I really like the amplifiers, I read mixed things about the classic series before I got them, but they really do it for me! .......
50: Tubes Asylum, RE: Best new tube for ARC Classic 150? (0.00)
Posted by maxhifi on 2021-03-01, 17:13:27 (75.152.195.50)
Thanks! .......
51: High Efficiency Speaker Asylum, Very nice, now please get it out of the kitchen! NT (0.00)
Posted by maxhifi on 2021-03-01, 13:30:59 (75.152.195.50)
- .......
52: Tubes Asylum, Best new tube for ARC Classic 150? (0.00)
Posted by maxhifi on 2021-03-01, 13:22:32 (75.152.195.50)
Looking to get some new tubes for my amplifiers - at present they have the Russian Gold Lion KT-88 replicas, which are about 8 years old. Still sound good, but are down on power a bit when measured. A .......
53: High Efficiency Speaker Asylum, RE: Have you heard the Sweet Sixteen speakers? link (0.00)
Posted by maxhifi on 2020-11-09, 16:59:34 (75.152.195.50)
I built a pair in 2014, using MCM full range drivers. The article spoke to me years ago and I could never get the idea out of my head. Building them was extremely fun, I even used an extremely dangero .......
54: Vintage Asylum, RE: Heathkit SS-1 (0.00)
Posted by maxhifi on 2018-11-08, 10:47:16 (184.70.180.2)
Haha Hopefully these ones are less trouble than the other sort .......
55: Vintage Asylum, Heathkit SS-1 (0.00)
Posted by maxhifi on 2018-11-07, 13:54:08 (184.70.180.2)
Does anyone have experience with the Heathkit SS-1? I'm going to pick up a pair of blond ones. .......
56: Tape Trail, RE: Quantegy 631 substitute? (0.00)
Posted by maxhifi on 2017-10-20, 10:16:57 (198.233.141.11)
What I've been doing, is since daughter was very little, we record an interview every year or so, on the same tape. It's fun to listen to the interviews, because she starts off as being barely able to .......
57: Tape Trail, RE: Quantegy 631 substitute? (0.00)
Posted by maxhifi on 2017-10-20, 10:08:45 (198.233.141.11)
Cool, thanks for the info! Nice to see a new tape on the market. .......
58: Tape Trail, RE: That's really good-sounding tape (0.00)
Posted by maxhifi on 2017-10-20, 10:08:04 (198.233.141.11)
Hi Dave, What sort of machine/bias are you running it at? My application isn't too critical, but I would like to make sure it's not way off. -Max .......
59: Tape Trail, RE: Quantegy 631 substitute? (0.00)
Posted by maxhifi on 2017-10-19, 08:56:39 (198.233.141.11)
Do you know who actually makes Capture? I was eyeing 930, as a good replacement for the old normal bias Quantegy/Ampex/Scotch/Realistic tapes I used to run. I'm using it for recording family memories .......
60: Tape Trail, Quantegy 631 substitute? (0.00)
Posted by maxhifi on 2017-10-18, 13:03:48 (198.233.141.11)
Hi guys, just a quick question. I want to do some tape recording with my trusty Ampex 800, and am out of new reels. Is there any newly made tape which can substitute for Quantegy/Ampex 631? I seem to .......
61: Tube DIY Asylum, RE: Memories from five years ago (0.00)
Posted by maxhifi on 2017-05-01, 12:41:48 (198.233.141.11)
Thank you, that must be why I didn't recognize them, we have nothing of the sort in North America. The anode caps on the 6R3s in my Priboi are much uglier, some cheap brown plastic. Wouldn't mind a g .......
62: Tube DIY Asylum, RE: Memories from five years ago (0.00)
Posted by maxhifi on 2017-05-01, 09:28:06 (198.233.141.11)
Where did you get those plate caps? .......
63: Tube DIY Asylum, RE: Photoflash Capacitors (0.00)
Posted by maxhifi on 2017-04-24, 11:29:15 (198.233.141.11)
I bought a bag of them years ago, the guy got them from a shop who pulled them out of disposable cameras. I used them to recap a bunch of old radios... really they're nothing special. In this day and .......
64: Tube DIY Asylum, Some Chinese stuff isn't half bad (0.00)
Posted by maxhifi on 2017-03-01, 14:31:13 (198.233.141.11)
I bought a Little Bear phono stage off eBay some time back. Threw out the plexiglass enclosure and mounted it into a Hammond Instrument enclosure, put some better quality RCAs and added tube shields. .......
65: Tube DIY Asylum, RE: Vintage Tubes (0.00)
Posted by maxhifi on 2017-02-28, 11:08:57 (184.151.222.182)
New old stock tubes have become prohibitively expensive, in most of the desirable audio types. The non audio tubes sell less because the guys who fix up old prewar radios have been dying. But are less .......
66: Tube DIY Asylum, RE: New Soul Sister pre (0.00)
Posted by maxhifi on 2017-02-22, 19:42:11 (206.75.129.36)
Higher drop than the 5U4, but it's far from whimpy... my RCA MI-12188A amplifiers have a 750-0-750 V power transformer, straight into the 5R4, then a choke input. They run at around 200mA with a B+ of .......
67: Tube DIY Asylum, RE: New Soul Sister pre (0.00)
Posted by maxhifi on 2017-02-22, 10:13:20 (198.233.141.11)
To address Jeff's point, the 5R4GY works great and reliable at high voltage. If you have one kicking around would be plug and play replacement in this application. .......
68: Tube DIY Asylum, RDH4 (0.00)
Posted by maxhifi on 2017-02-22, 08:20:12 (198.233.141.11)
I think RDH4 is pretty great, I especially like the section about power supplies and hum mitigation. I believe it's all online now too. The stuff about hi-fi is very dated, but still useful. There's a .......
69: Tube DIY Asylum, RE: 65uF capacitor? (0.00)
Posted by maxhifi on 2017-02-21, 15:15:13 (184.151.222.147)
You can downloaded RC-30 too, It's a bit newer than the '10. It really help to have the basics in your pocket. The rca tube manual isn't going to turn anyone into a prodigal amplifier designer, but it .......
70: Tube DIY Asylum, RE: Most likely it is that first 50H choke. (0.00)
Posted by maxhifi on 2017-02-21, 11:07:56 (198.233.141.11)
For a "quick fix", you could insert an additional filter stage, CR after the rectifier and before L1. This way use the R to drop voltage instead of making L1 act as choke input. C could be, say, 47uF .......
71: Tube DIY Asylum, RE: 65uF capacitor? (0.00)
Posted by maxhifi on 2017-02-21, 10:21:20 (198.233.141.11)
Sounds like you're on top of things. I strongly suggest reading the front section of any RCA tube manual, where it is explains how to design resistance capacitance coupled amplifiers, and how to draw .......
72: Tube DIY Asylum, RE: 65uF capacitor? (0.00)
Posted by maxhifi on 2017-02-21, 10:14:17 (198.233.141.11)
I thought it had to be a drawing error :) I notice there's only 2V on the bias diode of the ECC99, this explains the high current. If you add a couple diodes and get this to about 6V, I think everyth .......
73: Tube DIY Asylum, RE: 65uF capacitor? (0.00)
Posted by maxhifi on 2017-02-21, 10:06:13 (198.233.141.11)
If you connect the 65uF capacitor as shown, it's going to be effectively in parallel with the output transformer... this is BAD, it's going to kill the high frequency response of the amplifier. Old .......
74: Tube DIY Asylum, 65uF capacitor? (0.00)
Posted by maxhifi on 2017-02-21, 09:31:41 (198.233.141.11)
One question - is the 65uF capacitor really connected as shown? Agree with others about measuring voltage across the 22k resistor, you don't want to mess with using your meter as an ammeter. Check the .......
75: Tube DIY Asylum, Sharpen your pencil first (0.00)
Posted by maxhifi on 2017-02-17, 09:30:19 (184.151.222.177)
I do this I first draw a sketch of the schematic, then make that into a neat drawing Finally, add the component values. Some people are more comfortable using computers to draft things, I prefer a pen .......
76: Vinyl Asylum, cockroaches (0.00)
Posted by maxhifi on 2017-02-16, 12:52:42 (198.233.141.11)
I see I'm not the only one nuts enough to clean roaches and their leavings out of vintage audio gear rather than throw it out in disgust, like a sane person would :) .......
77: Tube DIY Asylum, JJ 2A3 maximum power. (0.00)
Posted by maxhifi on 2017-02-14, 09:52:20 (184.151.222.81)
What's the operating conditions you suggest for a lot more power? I have JJs too, may want to try the maximum power condition some day . .......
78: Tube DIY Asylum, RE: ECC99 Pin 9 confusion (0.00)
Posted by maxhifi on 2017-02-14, 09:43:35 (184.151.222.81)
Connect one wire from your 6.3V source to pin 9. If you use the tube normally, pins 4 and 5 are tired together, and connected to the other wire from the 6.3V source. If you plan only to use either the .......
79: Tube DIY Asylum, RE: mil spec colors (0.00)
Posted by maxhifi on 2017-02-14, 09:02:04 (198.233.141.11)
Thank you, this is cool, many great colours there. .......
80: Tube DIY Asylum, Old RCA amplifiers paint colour? (0.00)
Posted by maxhifi on 2017-02-13, 23:21:46 (206.75.129.36)
Am building some new SET amplifiers, and want to paint them the same shade of grey as 1950s RCA equipment. If anyone here has ever figured out a paint code for this colour I would really appreciate it .......
81: SET Asylum, SET for Home Theatre (0.00)
Posted by maxhifi on 2017-02-07, 11:58:05 (198.233.141.11)
You mentioned you use SET amplifiers for home theatre. Since first hearing about this idea (from you), I reconfigured my home theatre from a totally decent Denon/Triad 5.1 system, to a 2.0 stereo syst .......
82: Tube DIY Asylum, RE: Depends on your goals (0.00)
Posted by maxhifi on 2017-01-27, 14:59:09 (206.75.129.36)
I have achieved decent results paralleling specific circuit board traces on a couple commercial amps which were not that well designed with bare #14 from Romex - not the stuff of high end, sure, but i .......
83: Tube DIY Asylum, Could be money laundering? (nt) (0.00)
Posted by maxhifi on 2017-01-25, 08:38:34 (198.233.141.11)
- .......
84: Tube DIY Asylum, Depends on your goals (0.00)
Posted by maxhifi on 2017-01-24, 15:26:00 (198.233.141.11)
DIY audio is a leisure activity into itself. The idea that it's possible to make something in your garage which will compete viably with a highly praised $10k commercial product is of course complete .......
85: Tube DIY Asylum, Looks like they need a better engineer (0.00)
Posted by maxhifi on 2017-01-19, 13:20:19 (198.233.141.11)
This thing is pretty basic: The coupling caps are all 0.1, no attempt to spread out poles by using different value caps. 221k grid resistors are really high for fixed bias, I think KT88 datasheet says .......
86: SET Asylum, RE: what about the central locator pin? (0.00)
Posted by maxhifi on 2017-01-07, 11:06:28 (206.75.129.36)
Ground it. .......
87: SET Asylum, RE: 2A3 Options - KR Audio? (0.00)
Posted by maxhifi on 2017-01-04, 09:33:47 (198.233.141.11)
As it happens for reasons unrelated to amplifiers I plan to take a vacation to the Czech Republic this spring, and being an audio guy I had to look at what's out there. Coincidentally KR Audio is loca .......
88: Vintage Asylum, RE: Looking for info on these Studio Lab speakers (0.00)
Posted by maxhifi on 2016-12-26, 09:52:12 (206.75.129.36)
Doing a quick bit of google research I see these were marketed by a company called sonic international corp, from Portland Oregon. Notice it says "studio lab series ", this appears to be a model and n .......
89: SET Asylum, RE: This style is what I meant (0.00)
Posted by maxhifi on 2016-12-25, 05:53:24 (206.75.129.36)
Oh that's right. I got that one to use as part of a hum cancel network in old RCA amps, Thre original capacitor leaked an actual puddle of oil under the amp. My quest to replace like with like ended w .......
90: SET Asylum, Maximum Rg for jj2A3-40 fixed bias? (0.00)
Posted by maxhifi on 2016-12-24, 23:47:28 (206.75.129.36)
Would be fairly easy to change from cathode to fixed bias. Anyone know what the max Rg is for the JJ? I have 150k at present, it seems marginal for such a big tube in fixed bias. .......
91: SET Asylum, RE: Thank you for that info. (0.00)
Posted by maxhifi on 2016-12-24, 22:56:29 (206.75.129.36)
No problem, try antique electronic supply and go on from there, I have no doubt you will turn some up. .......
92: SET Asylum, RE: Anyone know of an Loctal type 6J5? (0.00)
Posted by maxhifi on 2016-12-24, 22:50:46 (206.75.129.36)
7A4 Merry Christmas! .......
93: SET Asylum, This style is what I meant (0.00)
Posted by maxhifi on 2016-12-23, 13:28:15 (206.75.129.36)
Russian pio .......
94: SET Asylum, RE: Thank you! (0.00)
Posted by maxhifi on 2016-12-23, 12:22:42 (174.90.222.130)
Merry Christmas to you too! Good to see you're still around here. Nice to see an an endorsement for the EH tubes too. .......
95: SET Asylum, Paper in Oil (0.00)
Posted by maxhifi on 2016-12-22, 13:08:16 (198.233.141.11)
There's the rectangular USSR made paper in oils all over eBay. I got a couple of them for another project, and they tested good on a Sprague tel-ohm-mike. Did not use them yet. Dead on value and no le .......
96: High Efficiency Speaker Asylum, RE: Yummy - looks like a really nice job! nt. (0.00)
Posted by maxhifi on 2016-12-22, 13:03:55 (198.233.141.11)
Thank you. They were a lot more work than I had originally planned on, definitely pushed the upper limit of my tools and skill as an amateur carpenter. .......
97: SET Asylum, Thank you! (0.00)
Posted by maxhifi on 2016-12-22, 12:45:55 (198.233.141.11)
I see that the state of the world hasn't changed since I got the JJs in the first place... it's good to know I made the right choice to begin with. The EML looks like a very nice tube but is too much .......
98: SET Asylum, RE: 2A3 Options (0.00)
Posted by maxhifi on 2016-12-22, 11:15:21 (198.233.141.11)
Are those Obbligato filter capacitors motor run caps which have been painted, or is there something else special about them? They look exactly like the capacitors usually connected to 4 pole single p .......
99: SET Asylum, RE: 2A3 Options (0.00)
Posted by maxhifi on 2016-12-21, 13:12:57 (198.233.141.11)
Valve Art 2A3s are what I had when I first built the amp... the JJs 2A3-40s are a huge improvement, I definitely don't want the old Valve Art tubes back. .......
100: SET Asylum, 2A3 Options (0.00)
Posted by maxhifi on 2016-12-21, 10:23:30 (198.233.141.11)
I've posted about my single ended triode amplifier in the past. It's got a Mullard EF37A driving a JJ 2A3-40, with a 6CA4 rectifier and a CLC power supply. Output transformers are Sowter SP-02, and p .......
101: High Efficiency Speaker Asylum, SANSUI SP-3005 rebuild updated (0.00)
Posted by maxhifi on 2016-12-20, 22:31:09 (206.75.129.36)
Finished new Cabinets a couple weeks ago, see attached photo. Tried them at first with push pull amplifiers. Enjoyed the sound, but today tried with single ended triodes (EF37A driving JJ2A3) they .......
102: High Efficiency Speaker Asylum, New cabinet (0.00)
Posted by maxhifi on 2016-12-05, 09:11:32 (70.28.245.77)
Here's one of the almost complete new cabinets Note to self : never buy Chinese made plywood again! The other one is a mirror image of this one .......
103: Tube DIY Asylum, RE: Take a look at some DHT tubes (0.00)
Posted by maxhifi on 2016-11-09, 09:07:36 (174.90.222.96)
Hi Vinnie I it were possible to quantify the improvement the 26 offers over the 56, 76, etc how would you describe it? I expect that the objective performance should be fairly similar, but am Interes .......
104: Tube DIY Asylum, Two circuits on JE Labs (0.00)
Posted by maxhifi on 2016-11-09, 08:39:23 (198.233.141.11)
I enjoyed building the open baffle speaker from the JE labs website. To make this clear are you guys using the 76 with the 6SN7 cathode follower, or with transformer coupling? He has both on the webs .......
105: Tube DIY Asylum, Take a look at 5687 (0.00)
Posted by maxhifi on 2016-11-08, 14:11:27 (198.233.141.11)
Yes!! Good call on the 5687, thank you, I have a few of those, in my tube stash, I used one as a concertina phase inverter in a push pull EL34 amplifier I built in the 1990s, that amplifier always sou .......
106: Tube DIY Asylum, RE: May need a cathode follower (0.00)
Posted by maxhifi on 2016-11-08, 10:45:45 (198.233.141.11)
Hi Tre, I was overestimating those values intentionally, just to try and figure out a worst case, that's where 500pf came from. I will move the pot to the input of my preamp, the only advantage I see .......
107: Tube DIY Asylum, RE: May need a cathode follower (0.00)
Posted by maxhifi on 2016-11-08, 09:02:47 (198.233.141.11)
Amplifier requires 3.3V RMS input for full output (hence need for preamp) Preamplifier will be driving a 6 foot patch cord, load impedance at input of amplifier will consist of miller capacitance o .......
108: Tube DIY Asylum, RE: Take a look at some DHT tubes (0.00)
Posted by maxhifi on 2016-11-08, 06:49:25 (206.75.129.36)
Ahh old radio tubes, after seeing your post I did some reading and saw the curves of a 56, they are indeed extremely linear. My only reservation with those is purely practical, I already have a whole .......
109: Tube DIY Asylum, RE: DIY Line Stage (0.00)
Posted by maxhifi on 2016-11-07, 16:24:45 (198.233.141.11)
To be honest choke input scares me a bit, my RCA amplifiers have it, and not only do the chokes buzz, but the high voltage winding of the power transformer is really lethal.. to be fair, I also really .......
110: Tube DIY Asylum, May need a cathode follower (0.00)
Posted by maxhifi on 2016-11-07, 16:21:33 (198.233.141.11)
That's what I was thinking, but I keep reading "cathode followers sound bad", without any really convincing explanation as to why. I definitely don't want it to sound bad, but the low output impedance .......
111: Tube DIY Asylum, RE: I had 20k in McIntosh gear and (0.00)
Posted by maxhifi on 2016-11-07, 16:18:44 (198.233.141.11)
Speakers are early 80s Klipsch La Scala, Tannoy Saturn S6. or some Sansui SP-3005 which I am building new cabinets for. Amplifier is either a pair of restored and slightly modified RCA MI-12188A, Dyn .......
112: Tube DIY Asylum, DIY Line Stage (0.00)
Posted by maxhifi on 2016-11-07, 15:40:30 (198.233.141.11)
Am getting a little bit tired of using my McIntosh C-24, I think it's the weak link in my system and would like to do something which sounds better, DIY style. Am thinking to use the following setup: .......
113: High Efficiency Speaker Asylum, RE: Japanese Brochure & specs (0.00)
Posted by maxhifi on 2016-10-27, 12:09:03 (184.151.222.47)
Thanks for the ideas! I am about to make a cap order at parts express for the original values, wil toss in some polypropylene caps too for later experimentation. Looking at the frequency response char .......
114: High Efficiency Speaker Asylum, RE: Driver recommendation for this horn? (0.00)
Posted by maxhifi on 2016-10-27, 09:25:45 (184.151.222.47)
What is that a picture of? .......
115: High Efficiency Speaker Asylum, Japanese Brochure & specs (0.00)
Posted by maxhifi on 2016-10-25, 14:57:28 (198.233.141.11)
I could find barely any info on these in English, so decided to search yahoo.jp. Up came lots of stuff, of course, I can only look at the photos, but the frequency response graph doesn't show any h .......
116: High Efficiency Speaker Asylum, Damping isn't an issue, but damping factor can be (0.00)
Posted by maxhifi on 2016-10-25, 09:15:59 (174.90.222.227)
A single ended triode amplifier without global feedback will have a damping factor much lower than 20, more like 3, and if it's connected to a speaker with a widely varying impedance curve (say a thre .......
117: High Efficiency Speaker Asylum, RE: Simplify Sansui Speaker Crossovers And Enjoy (0.00)
Posted by maxhifi on 2016-10-20, 08:52:18 (184.151.222.116)
I really like the sound of your approach, I wish I could work that sort of magic working empirically! will definitely post back with impressions of the completed rebuild! I will probably not modify cr .......
118: High Efficiency Speaker Asylum, RE: Simplify Sansui Speaker Crossovers And Enjoy (0.00)
Posted by maxhifi on 2016-10-19, 07:21:35 (206.75.129.36)
"even stock, they are a much better sounding speaker than Klipsch Heresy, which I also own." Wow now this is encouraging! I really excited to get mine operational! Those crossover modifications sound .......
119: High Efficiency Speaker Asylum, no kidding! And they aren't likely to have lung cancer! (0.00)
Posted by maxhifi on 2016-10-18, 17:01:21 (206.75.129.36)
When I opened the bottom of my la scalas, it smelled like someone was in the room chain smoking! I imagine they did some time in a bar somewhere! .......
120: High Efficiency Speaker Asylum, RE: First Listen, sign Crossover dead? (0.00)
Posted by maxhifi on 2016-10-16, 12:20:07 (206.75.129.36)
This is absolutely not normal. I would not suspect crossovers, a bad crossover would more likely result in muffled highs. In this case the chances are good that there's an issue with the electronics, .......
121: Tube DIY Asylum, RE: alternate circuit RE: Proposed schematic (0.00)
Posted by maxhifi on 2016-10-14, 08:56:57 (198.233.141.11)
"Max - I'm sorry, you are correct. I didn't study your drawing enough. BTW, I measured the switch contacts on the 10amp switches I've been using and with over ten years use, none measured more than 10 .......
122: High Efficiency Speaker Asylum, More to this than I thought. (0.00)
Posted by maxhifi on 2016-10-12, 22:29:54 (206.75.129.36)
I measured all the crossover values, and the driver impedances at crossover frequencies. Simulated using Passive Crossover Designer 7, It turns out the crossover is designed with a high Q to compensa .......
123: Tube DIY Asylum, RE: alternate circuit RE: Proposed schematic (0.00)
Posted by maxhifi on 2016-10-12, 15:35:59 (174.90.222.34)
Have a second look at my circuit, the 8 ohm resistor is never connected to the same amplifier which is connected to the speakers, and just like the dpdt circuit there's never more than two contacts in .......
124: High Efficiency Speaker Asylum, RE: Sansui SP-3005 project confusion (0.00)
Posted by maxhifi on 2016-10-12, 14:32:53 (174.90.222.34)
Those ports look very similar to mine. I'm mid way done building new cabinets for the so-3005s, am excited to hear them! .......
125: Tube DIY Asylum, Proposed schematic (0.00)
Posted by maxhifi on 2016-10-12, 14:17:41 (174.90.222.34)
Here's how I plan to hook it up in order to make sure I don't damage the tube amp. One switch for left and another for right, but only one shown here. The non active amp is presented with a big pow .......
126: Tube DIY Asylum, RE: DIY amplifier selector suggestions. (0.00)
Posted by maxhifi on 2016-10-12, 10:16:26 (174.90.223.54)
I'm already pricing out super long patch cords to unite the two systems. I think the theatre would sound a whole lot better though my big RCA amplifiers, than it does with the Denon receiver, but I ma .......
127: Tube DIY Asylum, RE: DIY amplifier selector suggestions. (0.00)
Posted by maxhifi on 2016-10-12, 10:12:07 (174.90.223.54)
They do look pretty robust. I will put 1A through them and check voltage drop with a sensitive VTVM. Similar US made switches claim 10m ohms, and the Chinese ones look fairly similar, and we're really .......
128: Tube DIY Asylum, RE: DIY amplifier selector suggestions. (0.00)
Posted by maxhifi on 2016-10-11, 15:21:32 (174.90.223.25)
That's more or less what I was picturing but it seems nobody makes good ones anymore! :) I picked up a pair of these on eBay... Plan is to hook them up So the amp not in use sees an 8 ohm resistor. .......
129: Tube DIY Asylum, DIY amplifier selector suggestions. (0.00)
Posted by maxhifi on 2016-10-11, 14:09:53 (174.90.223.25)
Simple problem, complex solution: Problem: want to share one set of speakers between my tube based stereo and solid state home theatre Solution: build a selection box Complicating factors: want extre .......
130: High Efficiency Speaker Asylum, RE: Sansui SP-3005 project confusion (0.00)
Posted by maxhifi on 2016-10-09, 16:09:52 (206.75.129.36)
Wow, that's a lot to endure! Hope everything ends up okay! It's cool you re-used some parts from the Sansui speakers. I've been drawing out a schematic for the crossover, it's a bit of a mess. Ther .......
131: High Efficiency Speaker Asylum, RE: Sansui SP-3005 project confusion (0.00)
Posted by maxhifi on 2016-10-07, 17:06:09 (206.75.129.36)
This is a good point, I think my DMM is pretty close, (claims to be true RMS over a broader range than I am testing) but will redo tests with a VTVM to confirm. What I think is screwing up the result .......
132: High Efficiency Speaker Asylum, Second Woofer Measurement (0.00)
Posted by maxhifi on 2016-10-07, 13:46:24 (206.75.129.36)
First Speaker: Fs = 36.38 Qms = 2.93 Qes = 0.987 Qts = 0.738 Second Speaker: Fs = 34.79 Qms = 2.86 Qes = 1.06 Qts = 0.77 Looks like they're not all that different from each other. .......
133: High Efficiency Speaker Asylum, RE: Sansui SP-3005 project confusion (0.00)
Posted by maxhifi on 2016-10-07, 08:58:48 (184.151.222.46)
Hi Art, Did you end up using your Sansui speakers? My living room system has klipsch la scalas, so this kind of bass roll-off isn't unfamiliar, and to be honest I listen to mostly older recordings on .......
134: High Efficiency Speaker Asylum, RE: Sansui SP-3005 project confusion (0.00)
Posted by maxhifi on 2016-10-06, 10:45:22 (198.233.141.11)
I'm going to measure the other woofer tonight, and see how close they are to each other. You guys may have a point, there's definitely no sense in building enclosures if the speakers are shot. ::: TOP .......
135: High Efficiency Speaker Asylum, RE: Sansui SP-3005 project confusion (0.00)
Posted by maxhifi on 2016-10-05, 22:18:10 (206.75.129.36)
Thank you for the encouragement. This project exists only for fun/learning. I don't think they will be competition for my good speakers. I find it fascinating how these speakers appear to be very goo .......
136: High Efficiency Speaker Asylum, RE: Sansui SP-3005 project confusion (0.00)
Posted by maxhifi on 2016-10-05, 09:07:44 (174.90.223.248)
I tried to input the same parameters into different software. The Sansui port appears to be tuned to 64Hz according to online calculators. I got around 70 using the helmholtz resonance formula, but th .......
137: High Efficiency Speaker Asylum, Sansui SP-3005 project confusion (0.00)
Posted by maxhifi on 2016-10-04, 23:01:53 (198.233.141.11)
Picked up a pair of these rather unique speakers a few years back in very poor shape, cabinets had got wet at some point (by previous owner) and bottoms totally rotted out. Left them in the garage as .......
138: Vintage Asylum, RE: Simpson multi meter follow up (0.00)
Posted by maxhifi on 2016-09-28, 07:19:11 (206.75.129.36)
I have a -8 and a -6 I prefer the new one because it's in better condition and has more useful scales, but they're very similar. After frying a DMM with a voltage spike, I tend to save the DMM for mea .......
139: High Efficiency Speaker Asylum, RE: A magnificent headphone system or a marvelous stereo in a crappy room? (0.00)
Posted by maxhifi on 2016-09-16, 06:51:26 (206.75.129.36)
I would find a way to make speakers work, even if it means abandoning high efficiency and listening to two way monitors in the near field to limit room effects. lots of great compact speakers exist :: .......
140: Tube DIY Asylum, RE: I'm going to share with you guys a little trick for finding the noise in amps or preamps. (0.00)
Posted by maxhifi on 2016-09-06, 08:39:13 (174.90.222.51)
I do this too... This is a great way to find noisy plate load resistors and noisy tubes. Cannot always short grid to ground directly since grid not always at 0VDC. Another noise finding tip: I've had .......
141: Vintage Asylum, RE: Yeah but the article used present tense (0.00)
Posted by maxhifi on 2016-08-19, 13:40:06 (206.75.129.36)
That's what I was thinking! Though i was quietly hoping some boutique maker set up which I hadnt heard about yet! .......
142: Vintage Asylum, Yeah but the article used present tense (0.00)
Posted by maxhifi on 2016-08-19, 12:59:51 (206.75.129.36)
I've got lots of old made in Canada tubes from the tube era but the article used present tense and listed Canada amongst countries where tubes are still being made. .......
143: Vintage Asylum, what tubes are made in Canada? (0.00)
Posted by maxhifi on 2016-08-19, 12:26:41 (206.75.129.36)
Was surprised to read that in the article. .......
144: High Efficiency Speaker Asylum, RE: screw size for Klipsch heritage network terminal blocks? (0.00)
Posted by maxhifi on 2016-08-17, 16:28:39 (206.75.129.36)
A new terminal strip can be had from any supplier catering to industrial customers, check the yellow pages if you're in a big city. This type of barrier strip is called a cinch terminal block after th .......
145: High Efficiency Speaker Asylum, RE: What is a revere? (0.00)
Posted by maxhifi on 2016-08-17, 11:01:16 (206.75.129.36)
do they sound any good? Looks like a PA grade speaker from years past. .......
146: High Efficiency Speaker Asylum, What is a revere? (0.00)
Posted by maxhifi on 2016-08-16, 07:58:25 (24.67.164.56)
Have to ask .......
147: Vinyl Asylum, RE: Cartridge Replacement (0.00)
Posted by maxhifi on 2016-08-08, 12:25:54 (184.151.222.124)
Can't speak for compatibility but I would say in that price the ortofon blue is a solid choice. It has a nude diamond which is not always found in this price range. .......
148: High Efficiency Speaker Asylum, RE: These work good also ............ (0.00)
Posted by maxhifi on 2016-08-08, 10:14:47 (184.151.222.124)
Interesting. Looks a lot more durable than a vintage driver too, and not a bad price at all. Thanks for the link! .......
149: High Efficiency Speaker Asylum, RE: Yep... (0.00)
Posted by maxhifi on 2016-08-08, 08:43:22 (184.151.222.124)
I really like the T35s in my la scales, that's a super idea. Sadly II sold my old goodmans triaxiom speakers before I thought about open baffles. Am thinking about seeking out some GE 1201a drivers, h .......
150: High Efficiency Speaker Asylum, JE Labs Open Baffle (0.00)
Posted by maxhifi on 2016-08-07, 21:50:46 (206.75.129.36)
Built a pair today, got some 3/4 particle board at Lowes and built exactly as per plan. It's possible to make a pair from one sheet. Didn't even bother with the table saw just used a straight edge and .......
151: Vinyl Asylum, RE: Rare David Bowie lp sells for over $10,000 (0.00)
Posted by maxhifi on 2016-05-29, 08:31:41 (174.90.223.160)
You made me run down to my records, I just listened to this one last week! I had to check mine... Mine is clearly marked "counterfeit" from the record dealer I got it from - darn it :) .......
152: Vinyl Asylum, RE: Tachometer to measure speed. (0.00)
Posted by maxhifi on 2016-05-27, 11:09:19 (198.233.141.11)
I've looked into those before, and they usually seem to be intended for measuring higher speeds, like for example hundreds or thousands of RPM, and offer insufficient precision at low speeds. The set .......
153: Vinyl Asylum, RE: If it is a great table it deserves a (0.00)
Posted by maxhifi on 2016-05-26, 19:48:10 (184.151.222.215)
Nah it's an old portable record player, having fun tinkering with it but not about to invest $$$, on the other hand I'm going to google them anyway, learning is always good .......
154: Vinyl Asylum, RE: Strobe discs to measure speed. (0.00)
Posted by maxhifi on 2016-05-26, 19:45:00 (184.151.222.215)
Gave it a try, the iPhone app RPM (iPhone 5) measures about 33.0 rpm when the strobe pattern on my thorena stands still. Same for the strobe disk and LED light on two other turntables. Frequency count .......
155: Vinyl Asylum, RE: Strobe discs to measure speed. (0.00)
Posted by maxhifi on 2016-05-26, 13:12:39 (184.151.222.215)
Thank you! This is exactly what I wanted to know. Need to shave down a motor shaft to change an old Turntable from 50hz to 60hz and want to measure things along the way. .......
156: Vinyl Asylum, Strobe discs to measure speed. (0.00)
Posted by maxhifi on 2016-05-26, 12:10:57 (184.151.222.215)
I understand that with a strobe disk, the pattern will stand still once the speed is correct. If I want to instead measure an arbitrary speed, can I vary the frequency of the flashing of the lamp bein .......
157: Vintage Asylum, RE: Here is a Russian tube type color set. (0.00)
Posted by maxhifi on 2016-05-23, 20:23:24 (206.75.129.36)
You're not kidding, that video nearly made me seasick! I like tube TVs, I have a couple of old RCAs from the sixties, and a philco predicta. One of those foreign sets would be fun to restore but I th .......
158: Vintage Asylum, RE: Look at this 1976 Russian TV and the reason I show it is because we use (0.00)
Posted by maxhifi on 2016-05-23, 16:59:12 (206.75.129.36)
I have a small collection of USSR consumer electronics, if you like that TV should check out some of their hifi equipment and radios. .......
159: Tube DIY Asylum, RE: I still think this site is more hard core and less commercialized. (0.00)
Posted by maxhifi on 2016-05-19, 21:50:39 (206.75.129.36)
I mean that here, the topics are varied and interesting, where AK has interesting topics too but there's also a lot of fairly repetitive threads which get a bit boring. I've managed to learn a lot mor .......
160: Tube DIY Asylum, RE: I still think this site is more hard core and less commercialized. (0.00)
Posted by maxhifi on 2016-05-18, 20:39:48 (206.75.129.36)
AK has its moments (I.e. Some of the threads on modifications done to radio shack speakers a few years ago were fun to read), but AA has a better signal to noise ratio. .......
161: Tube DIY Asylum, RE: Cathode-Powered Filaments (0.00)
Posted by maxhifi on 2016-05-04, 22:23:51 (206.75.129.36)
Well, the left and right sides aren't identical, it's hard to like this circuit as is. If one wanted to keep it you could use pin four of the 12AX7 for, say, left, and pin 5 for right, and ground pin .......
162: Tube DIY Asylum, RE: Grounding??? (0.00)
Posted by maxhifi on 2016-05-04, 22:01:43 (206.75.129.36)
I would leave it alone, the UL knows what they are doing, if it comes without a ground wire it has a split bobbin power transformer and double insulation... Ground the chassis and you may introduce a .......
163: Tube DIY Asylum, RE: Well...... (0.00)
Posted by maxhifi on 2016-04-30, 09:04:47 (206.75.129.36)
Yes, I meant if the absolute value of the grid to filament or cathode voltage increases, (with the grid always being more Negative than the cathode or filament) the resistance of the tube from filamen .......
164: Tube DIY Asylum, RE: Well...... (0.00)
Posted by maxhifi on 2016-04-30, 00:57:21 (206.75.129.36)
I am confused by a few things here 1. There is no cathode in any of these tubes. I assume plate to cathode means plate to one of the filament pins, or to the centre tap of the hum balance pot. 2. If y .......
165: Tube DIY Asylum, RE: Another excellent troubleshooting video and theory behind it (0.00)
Posted by maxhifi on 2016-04-23, 10:24:46 (206.75.129.36)
I am fixing up an old 1935 era GE radio, and despite the 350V B+ it needs 500V capacitors... I calculated the surge voltage to be 505V, and that assumes 115V AC line. I will probably use 2 350V units .......
166: Tube DIY Asylum, RE: Another excellent troubleshooting video and theory behind it (0.00)
Posted by maxhifi on 2016-04-22, 22:48:03 (174.90.222.161)
The take away from this video, is that your filter caps may need a way higher voltage rating than you think. .......
167: Tube DIY Asylum, RE: No, those suckers get really hot (0.00)
Posted by maxhifi on 2016-04-18, 20:00:35 (174.90.222.22)
Some variation is normal but shouldn't be drastic. Begin by drawing a really accurate schematic, make a photocopy for the second channel and then record the DC voltage to ground at each of the tube te .......
168: Tube DIY Asylum, RE: No, those suckers get really hot (0.00)
Posted by maxhifi on 2016-04-18, 16:47:32 (70.28.245.7)
Thing is, if that amplifier is working at the shown operating point, the resistor should only be dissipating 1.5W. (41Vx0.036A), which shouldn't kill the capacitor right away even mounted like that. .......
169: Tube DIY Asylum, RE: hot time in the old cap tonight.... (0.00)
Posted by maxhifi on 2016-04-18, 14:12:31 (198.233.141.11)
I think he meant jumper leads to put the resistor back into the circuit, for testing purposes.. this layout isn't bad, I really like the use of bus wire as a ground down the middle, it's very RCA. ::: .......
170: Tube DIY Asylum, RE: hot time in the old cap tonight.... (0.00)
Posted by maxhifi on 2016-04-18, 09:13:05 (198.233.141.11)
This can be a few things, cap voltage rating too low, shorted 45 drawing too much current, thus over voltage on cap, cap installed backwards.. don't like how cap is so close to resistor either, better .......
171: High Efficiency Speaker Asylum, 6.5" speakers (0.00)
Posted by maxhifi on 2016-04-15, 10:21:53 (198.233.141.11)
Which 6.5" speaker are you specifically talking about? .......
172: Vinyl Asylum, RE: "A 78 stacker may be in my future." I can just hear (feel?) that 12" 78 dropping down on to the one below; ... (0.00)
Posted by maxhifi on 2016-04-15, 07:29:55 (206.75.129.36)
I play them on an Early 50s VM changer, I think the idea of it cracking or damaging records is exaggerated, it sure never happened to me. The springs under the changer seem to dampen the force very we .......
173: Vinyl Asylum, RE: Anyone use a record changer ? (0.00)
Posted by maxhifi on 2016-04-12, 12:35:38 (174.90.223.136)
Yep high level tape input - actually it does have a tape head input too, but that's not what I am using (NAB eq) . Just to make sure I have you right - cartridge feeds into 100pf cap, straight into no .......
174: Vinyl Asylum, RE: Anyone use a record changer ? (0.00)
Posted by maxhifi on 2016-04-12, 05:13:21 (174.90.223.136)
Hi Phil, I am using it on the "Tape" input of my old mcintosh C24, I put the 1M resistors in series with the signal, right under the player chassis, without them the 47k input impedance of the C24 des .......
175: Vinyl Asylum, Anyone use a record changer ? (0.00)
Posted by maxhifi on 2016-04-11, 22:10:50 (174.90.223.136)
Yep I know it sounds crazy, but I like to listen to music while I am working at home, and changing records was becoming distracting, so hooked up a BSR changer to the system and put on a stack of reco .......
176: Vintage Asylum, RE: Now this is a test bench we can all be Jealous of. (0.00)
Posted by maxhifi on 2016-04-04, 10:07:28 (198.233.141.11)
I enjoy his videos too. I think they do go on a bit long sometimes though, I rarely end up watching one all the way through. .......
177: Vintage Asylum, RE: Hallicrafters video of 1940 to 1945 I would guess. (0.00)
Posted by maxhifi on 2016-04-04, 09:49:49 (198.233.141.11)
I have a couple lower end models, an S-40 and an S-77. The 77 is a hot chassis, and a bit lower quality but it otherwise similar to the S-40. The S-40 is really beat up and used. Have yet to do a reca .......
178: Vintage Asylum, RE: Hallicrafters video of 1940 to 1945 I would guess. (0.00)
Posted by maxhifi on 2016-04-02, 06:31:38 (206.75.129.36)
Does yours have an ashtray on it ? :) I like how the women on the assembly line have their names on their tool boxes, and look at that wiring harness. What a cool video thanks for sharing... Makes me .......
179: Tube DIY Asylum, This is the capacitor I was talking about (0.00)
Posted by maxhifi on 2016-03-31, 16:51:39 (174.90.223.96)
Nt .......
180: Tube DIY Asylum, RE: The capa wth grounded cases typically had different terminals (0.00)
Posted by maxhifi on 2016-03-31, 13:22:01 (198.233.141.11)
Annoyingly pre was mono... looked like part of a radio station's rack mount equipment. I have the input and output transformers and most of the parts but took the unit apart 25 years ago before I unde .......
181: Tube DIY Asylum, Thanks all for opinions! (0.00)
Posted by maxhifi on 2016-03-31, 12:19:19 (198.233.141.11)
Shielding or lack thereof was what worried me about it to begin with - floating metal just seemed a bad idea. Also, I used to have an old Westinghouse broadcast microphone preamp with UTC transformers .......
182: Vintage Asylum, RE: A "better" speaker? (0.00)
Posted by maxhifi on 2016-03-30, 16:04:52 (198.233.141.11)
A pair of those corner speakers was on eBay a few years ago, with lots of pictures... very neat looking. .......
183: Tube DIY Asylum, Dumb question - Russian PIO (0.00)
Posted by maxhifi on 2016-03-30, 15:07:42 (174.90.223.59)
I asked for some advice about coupling capacitor a while back, for my RCA mono amplifiers, and settled on Russian PIO tubular caps. I needed 8 and ordered 10, all test good for tolerance (most are abo .......
184: Tube DIY Asylum, RE: That's really good advice, +1... (nt) (0.00)
Posted by maxhifi on 2016-03-30, 14:36:03 (198.233.141.11)
Hmm let's see. One time I wasn't paying attention and shocked myself on 450V B+, which made me quickly move my arm out of the way, catching a speaker wire, pulling the amplifier off the table and fal .......
185: Vintage Asylum, RE: Jesus wept ... (0.00)
Posted by maxhifi on 2016-03-30, 08:15:17 (174.90.223.59)
I wonder if that mid driver is anything special, it sure looks promising .......
186: Tube DIY Asylum, That's really good advice, +1... (nt) (0.00)
Posted by maxhifi on 2016-03-30, 07:39:52 (198.233.141.11)
nt .......
187: Vintage Asylum, RE: Combining vintage stereo gear with modern digital cable/flat panels (0.00)
Posted by maxhifi on 2016-03-28, 20:31:07 (206.75.129.36)
A Y adaptor isn't directional, it's just a piece of wire connecting L and R, essentially putting them in parallel, and combining them together. Bet if you disconnect one channel before the "combiner" .......
188: Vintage Asylum, RE: Combining vintage stereo gear with modern digital cable/flat panels (0.00)
Posted by maxhifi on 2016-03-28, 12:01:22 (174.90.223.20)
"The first thing I did was split the mini jack audio out with a 3.5 mini jack to two female plugs. Then I Y that again and then recombine one of those for a mono line level signal that I send to the s .......
189: Vinyl Asylum, Agreed, the little bear is great (0.00)
Posted by maxhifi on 2016-03-26, 09:29:44 (184.151.222.12)
I built mine into a Hammond instrument cabinet, and added tube shields and a lighted power switch. . Sounds fantastic with stock tubes... The closed case and good sound quality have discouraged me .......
190: Vintage Asylum, RE: Coaxial kits -1950s (0.00)
Posted by maxhifi on 2016-03-24, 10:39:22 (174.90.223.113)
So many products made at that time - go to the link below and look at audio magazine, from the intended time frame. You will probably find all the answers you want with a bit of digging. .......
191: Vintage Asylum, RE: Which Tester ? (0.00)
Posted by maxhifi on 2016-03-22, 13:12:18 (174.90.223.192)
I have two testers, an eico 667 and a military tv-7 I suggest to keep the eico for the following reasons: 1. It does a great job checking heater to cathode leakage, not all testers do this 2. It test .......
192: Tube DIY Asylum, RE: Vacuum Impregnation/choke buzz (0.00)
Posted by maxhifi on 2016-03-22, 07:08:52 (174.90.223.192)
This is interesting In which way do you see the deterioration manifest? With these amplifiers I believe they could have buzzed when new - all photos of original installations of these and similar RCA .......
193: Tube DIY Asylum, RE: Vacuum Impregnation/choke buzz (0.00)
Posted by maxhifi on 2016-03-21, 22:12:25 (184.151.222.88)
I am getting the parts values from the original RCA schematic, all parts are original in my amps. The schematic commonly seen online is based on a reverse engineered amplifier and contains some errors .......
194: Tube DIY Asylum, RE: Vacuum Impregnation/choke buzz (0.00)
Posted by maxhifi on 2016-03-21, 13:55:22 (198.233.141.11)
I did a bit of fooling around with PSUD, top image is stock, bottom is with a capacitor and some series resistance added. It does bring down the AC current through the inductor substantially, but I .......
195: Tube DIY Asylum, RE: There is some truth this article. (0.00)
Posted by maxhifi on 2016-03-21, 12:00:47 (198.233.141.11)
Live and let live... imagine how annoying it would be if everyone you know evangelized their hobbies all the time, I say leave high quality audio for people who go out of their way to find it. Those .......
196: Tube DIY Asylum, RE: Vacuum Impregnation/choke buzz (0.00)
Posted by maxhifi on 2016-03-21, 11:02:53 (198.233.141.11)
"That was my finding as well, I could feel movement between the i's and e's with my finger when the offending choke was buzzing." It's subtle but definitely possible to feel "Another question, were t .......
197: Tube DIY Asylum, RE: Vacuum Impregnation/choke buzz (0.00)
Posted by maxhifi on 2016-03-21, 10:48:31 (198.233.141.11)
I sure don't like the sound of that (changing the sound of the amp).. the buzz from the chokes isn't so terrible, it's just the last little detail which would make things perfect. In the past I had th .......
198: Tube DIY Asylum, RE: Vacuum Impregnation/choke buzz (0.00)
Posted by maxhifi on 2016-03-21, 10:40:54 (198.233.141.11)
OK this is interesting! For clarity let me see if I understand you. "loosen hardware" - assume these are the four bolts in the corners of the E-I laminations? "insert appropriate gap material" - the .......
199: Tube DIY Asylum, Vacuum Impregnation/choke buzz (0.00)
Posted by maxhifi on 2016-03-21, 09:15:08 (198.233.141.11)
Been doing some work on some vintage amplifiers - RCA MI-12188A One feature of these amplifiers, is a choke input power supply. One downside to this feature, is the 13H chokes tend to buzz. It's not .......
200: SET Asylum, Fighting hum (0.00)
Posted by maxhifi on 2016-03-18, 22:28:35 (206.75.129.36)
So after I got my la scalas, it was basically like hooking my stereo up to a signal tracer and cranking the gain all the way... Hum, hiss, thermal noise, ticking sounds, insanity... The amp was fine w .......
201: Tube DIY Asylum, RE: Do yourself a favor as you sound like you may have limited experience. (0.00)
Posted by maxhifi on 2016-03-17, 19:10:48 (174.90.222.145)
Well in any case it's not really harder than building a kit. Just be sure to get something simple And in good working condition. A heathkit may be a good choice or an eico .......
202: Tube DIY Asylum, RE: Do yourself a favor as you sound like you may have limited experience. (0.00)
Posted by maxhifi on 2016-03-17, 16:39:16 (174.90.222.145)
They can be pretty simple, I fixed one up when I was a teenager, if you pick a simple one with a push-pull 6V6 amplifier it shouldn't need more than about ten capacitors to work like new, unless you'r .......
203: Tube DIY Asylum, RE: Eli Duttman ?.. Can a 6SL7 work in a RCA 12AX7 phono stage curcuit ? (0.00)
Posted by maxhifi on 2016-03-17, 13:54:32 (198.233.141.11)
That's exactly what worries me. I like the idea of a 6SL7 phono stage but don't want to compromise RIAA accuracy. .......
204: Vintage Asylum, RE: Got a 6-inch alnico Weber today (0.00)
Posted by maxhifi on 2016-03-17, 13:52:18 (198.233.141.11)
Take some photos if you get a chance, I would like to see the little Webber. .......
205: Tube DIY Asylum, RE: Do yourself a favor as you sound like you may have limited experience. (0.00)
Posted by maxhifi on 2016-03-17, 13:39:38 (198.233.141.11)
Mono? Did you say Mono? You want to stay mono indefinitely? Here is my opinion: There's lots of orphan mono era integrated amplifiers out there who are unlikely to find a mate, which would make a fine .......
206: Tube DIY Asylum, RE: Eli Duttman ?.. Can a 6SL7 work in a RCA 12AX7 phono stage curcuit ? (0.00)
Posted by maxhifi on 2016-03-17, 10:25:02 (198.233.141.11)
Did you make any changes in component values to the RCA circuit in order to accommodate the 6SL7, or was it straight out of the back of the tube manual but with a different tube?? .......
207: SET Asylum, RE: Bass VS La Scalas (0.00)
Posted by maxhifi on 2016-03-17, 09:38:23 (198.233.141.11)
I suppose it wouldn't be life without compromise... I like the la scalas a lot but I can see why someone who is after deep bass response would be turned off them. I haven't got the space or budget for .......
208: SET Asylum, RE: Many many problems (0.00)
Posted by maxhifi on 2016-03-17, 09:29:41 (198.233.141.11)
"could very well be. I didn't meant to commit on that position per se, just the technical reasoning behind it." And thank you for doing so, more knowledge is always better! .......
209: Vintage Asylum, RE: Voltage check (0.00)
Posted by maxhifi on 2016-03-17, 07:09:31 (174.90.222.145)
Stuff like this is almost enough to make me want to learn to play guitar! I wish that companies like Webber and "Jensen" would make a "hifi" speaker based on 1950s technology, I would buy it in a hear .......
210: SET Asylum, RE: Many many problems (0.00)
Posted by maxhifi on 2016-03-17, 07:01:37 (174.90.222.145)
This makes a whole lot of sense. Concert sound looks like a real challenge, especially outdoor concerts! The reason I didn't account for the sum of two speakers, is I tend to listen to a fair niumber .......
211: SET Asylum, RE: Many many problems (0.00)
Posted by maxhifi on 2016-03-16, 19:38:54 (206.75.129.36)
This is a really good, and somewhat surprising point, which I had never considered before, and cannot say I fully understand. I think it merits further reading, thanks for raising it. .......
212: Vintage Asylum, RE: Voltage check (0.00)
Posted by maxhifi on 2016-03-16, 12:27:50 (174.90.222.145)
That wooden cradle which is holding the chassis is really cool, gotta get me one of those. I didn't have a lot of hope for that speaker. Does the "slow start" rectifier have less voltage drop than a u .......
213: SET Asylum, RE: Many many problems (0.00)
Posted by maxhifi on 2016-03-16, 10:33:27 (198.233.141.11)
I think that a couple things could be at play there. But one of them is that there's no way that speaker is actually 97dB sensitive across the board - see link below. If we are dealing with a 94.6 dB .......
214: SET Asylum, RE: Need some opinions and maybe a lot of help with 300Bsign.ree (0.00)
Posted by maxhifi on 2016-03-16, 07:58:08 (198.233.141.11)
Another thing to consider is using a well known design as a starting point, for example the JE labs circuit, it's more or less the most ubiquitous entry level 300B amplifier on the 'net, and won't .......
215: SET Asylum, RE: Need some opinions and maybe a lot of help with 300B design. (0.00)
Posted by maxhifi on 2016-03-14, 23:16:37 (174.90.223.60)
It's not so bad, just increase that 10uf input capacitor to say 40 or 50uF. Download PSUD and play around to get the right voltage level, you're on the right track. If you wanted a choke input power s .......
216: Speaker Asylum, Early detection is the key to prevention, get a cableoscopy! (0.00)
Posted by maxhifi on 2016-03-12, 07:08:13 (206.75.129.36)
Nt .......
217: Vintage Asylum, RE: Eico HF-12 power tranny question (0.00)
Posted by maxhifi on 2016-03-11, 21:41:33 (206.75.129.36)
I would hook the primary up to a variac, with all secondaries disconnected, and then slowly ramp it up to operating voltage, monitoring current - turning it back down immediately if there's any signif .......
218: Vintage Asylum, RE: High compliance ceramic cartridges (0.00)
Posted by maxhifi on 2016-03-11, 15:24:58 (206.75.129.36)
That is cool ! Kind of in a class of its own, I totally overlooked it browsing their catalogue. Some company in the Netherlands is selling them for 29'euros, I have to check the exchange rate. ::: TOP .......
219: Vintage Asylum, RE: High compliance ceramic cartridges (0.00)
Posted by maxhifi on 2016-03-11, 11:36:16 (198.233.141.11)
I got it to work - lots of interesting things in their old catalogue - I remembered right away what you were talking about, I used to check out their website from time to time when it was active One .......
220: High Efficiency Speaker Asylum, RE: RCA broadcast/commercial -- heck, yeah! (0.00)
Posted by maxhifi on 2016-03-11, 09:57:11 (198.233.141.11)
Would like to take the opportunity to thank you for the excellent website! I will send you an email later today once I am home. .......
221: Tube DIY Asylum, RE: RE How do you get 6.3 vdc for filaments? (0.00)
Posted by maxhifi on 2016-03-11, 09:42:37 (198.233.141.11)
What's wrong with series heaters? For one thing they're designed for it, and for another with reduced current you get more bang for your buck out of filter capacitors and rectifiers. I am planning a p .......
222: High Efficiency Speaker Asylum, RE: Some of it is here: (0.00)
Posted by maxhifi on 2016-03-10, 21:18:31 (206.75.129.36)
I forgot how good the photos page is, thanks for posting this. .......
223: Vintage Asylum, RE: 1955 tweed Fender Champ (0.00)
Posted by maxhifi on 2016-03-10, 15:17:29 (198.233.141.11)
Yeah, could always just recap it and put the old ones into s zip lock bag for future reference. I like how simple it is.. did you do a frequency sweep on the speaker and see if it's still in good shap .......
224: Vintage Asylum, RE: 1955 tweed Fender Champ (0.00)
Posted by maxhifi on 2016-03-10, 09:26:20 (198.233.141.11)
I would also worry about that red "Astron" which connects the chassis to the line! If that one is shorted it won't benefit the longevity of the guitar player! On the other hand it's so nice to look a .......
225: Vintage Asylum, RE: 1955 tweed Fender Champ (0.00)
Posted by maxhifi on 2016-03-10, 06:47:00 (206.75.129.36)
It's beautiful how original it is in there! Are those capacitors still operational? And who would think fender would use an off the shelf power transforner! Do the early ones use a way high voltage on .......
226: Vintage Asylum, RE: High compliance ceramic cartridges (0.00)
Posted by maxhifi on 2016-03-09, 09:59:45 (198.233.141.11)
Thanks for this interesting bit of history... I thought the Weathers speakers which look like books were a pretty cool setup (never seen them in the flesh though), and sure are the ancestor to the Bos .......
227: Vintage Asylum, Decca Specs (0.00)
Posted by maxhifi on 2016-03-09, 09:57:53 (198.233.141.11)
Found this on another forum: Decca Deram Ceramic: Stereo / Mono cartridge. White shell: transcription quality. Playing weight 2 gm; Tip mass 0.6gm Compliance: 9 x 10-6 lateral, 5 x 10-6 vertical. F .......
228: Vintage Asylum, RE: High compliance ceramic cartridges (0.00)
Posted by maxhifi on 2016-03-08, 19:49:08 (184.151.222.232)
Oh awesome thank you I checked out the Decca you referred to - looks amazing for a ceramic and they're still around too. .......
229: High Efficiency Speaker Asylum, RE: Carousel CD Player (0.00)
Posted by maxhifi on 2016-03-08, 14:14:19 (198.233.141.11)
Just giving you a hard time - and I am not one to talk, I have one of those 300 disc pioneer changers under the stairs which I bought in the late 1990s... what a stupid idea that one was! .......
230: Vintage Asylum, RE: High compliance ceramic cartridges (0.00)
Posted by maxhifi on 2016-03-08, 13:32:31 (184.151.222.232)
What's the brand/model ? .......
231: Vintage Asylum, RE: High compliance ceramic cartridges (0.00)
Posted by maxhifi on 2016-03-08, 13:12:20 (184.151.222.232)
Hi Eli, My plan is to use a 6J7 with a DC filament, and a 1-2M grid reaistor. I will use my turntable's existing SME tonearm wiring, I like your idea of close coupling but don't want to mess with what .......
232: Vintage Asylum, RE: High compliance ceramic cartridges (0.00)
Posted by maxhifi on 2016-03-08, 13:03:52 (184.151.222.232)
Hi Phil Yes the RC-30 circuit comes to mind for me too now that you mention it. I would go for metal octal tubes just because I want to match the look and feel of other gear in my system, but I think .......
233: Vintage Asylum, RE: High compliance ceramic cartridges (0.00)
Posted by maxhifi on 2016-03-08, 10:35:34 (198.233.141.11)
Hi Phil Yes, this is sort of my thinking.. I want to mount one onto a (genuine) SME headshell, align it correctly, and see what sort of performance I can squeeze out of it. The microacoustics isn't re .......
234: Speaker Asylum, May have to chalk this one down to experience! (0.00)
Posted by maxhifi on 2016-03-08, 08:25:19 (198.233.141.11)
Troubleshooting a rattle sound I took the cover off the bottom of one of my la scalas, and got a whiff of smoke so strong it smelled like a European taxi... I guess their previous life involved a smok .......
235: Vintage Asylum, High compliance ceramic cartridges (0.00)
Posted by maxhifi on 2016-03-08, 07:57:27 (184.151.222.232)
As per subject kind of want to try one just for fun. I noticed a subset of ceramic cartridges have great specifications in terms of compliance, tracking force, and frequency range. Would like to insta .......
236: High Efficiency Speaker Asylum, RE: vintage speaker repair - advice solicited (0.00)
Posted by maxhifi on 2016-03-07, 14:51:07 (198.233.141.11)
This has been added to the shopping list - thank you! .......
237: High Efficiency Speaker Asylum, RE: ship them (0.00)
Posted by maxhifi on 2016-03-07, 14:48:21 (198.233.141.11)
Now this begs the question - what is a self respecting audio asylum inmate doing with a carousel style CD player? :) .......
238: High Efficiency Speaker Asylum, RE: vintage speaker repair - advice solicited (0.00)
Posted by maxhifi on 2016-03-07, 13:49:41 (174.90.223.65)
Organ damage? Higher than a kite? Hmmm thanks for the warning, was thinking about performance as a solvent and not health and safety, definitely don't want to trade damaged speakers for damaged organ .......
239: High Efficiency Speaker Asylum, RE: ship them (0.00)
Posted by maxhifi on 2016-03-07, 11:59:15 (174.90.223.65)
"I now live in a marriage headed for divorce and the original buyer caused 90% of this with that darn box sitting in our house as I waited for the drivers to be picked for 2 years and my wife keep ple .......
240: High Efficiency Speaker Asylum, RE: vintage speaker repair - advice solicited (0.00)
Posted by maxhifi on 2016-03-07, 05:53:50 (174.90.223.65)
Got some acetone from the garage last night and gave it a try - it melts the black speaker lead glue quite easily, I let it soak into the glue around the felt dust cap of the oaktron and it popped rig .......
241: High Efficiency Speaker Asylum, vintage speaker repair - advice solicited (0.00)
Posted by maxhifi on 2016-03-06, 15:37:41 (206.75.129.36)
One problem I have encountered on some vintage speakers, is glue which has reached the end of its life - dried out and not sticky anymore. This results in spiders which come loose, and make frequency .......
242: High Efficiency Speaker Asylum, RE: RCA broadcast/commercial -- heck, yeah! (0.00)
Posted by maxhifi on 2016-02-25, 05:41:57 (184.151.222.21)
I found what I needed on my old laptop! Luckily I had Downloaded the catalogs back in 2009 or 2010. I actually did contact Oswald mills a while back and the reaponse was that there is no plan to bring .......
243: High Efficiency Speaker Asylum, found it (0.00)
Posted by maxhifi on 2016-02-24, 22:54:21 (206.75.129.36)
here you go - from RCA sound products catalog 218 .......
244: High Efficiency Speaker Asylum, RE: RCA broadcast/commercial -- heck, yeah! (0.00)
Posted by maxhifi on 2016-02-24, 10:01:48 (198.233.141.11)
:) Nuts? I think I am guilty of this! (one doesn't check into an asylum without any reason, right?) I LOVE that website... have spent hours and hours reading different publications, everything from Ra .......
245: Tubes Asylum, RE: McINTOSH MC-30 & FISHER 90-C REBUILD by MIKE SAMRA (0.00)
Posted by maxhifi on 2016-02-24, 09:41:40 (198.233.141.11)
Cool, am thinking of going in that direction. Vintage mono preamps are still fairly affordable compared to their stereo cousins of a similar quality. .......
246: High Efficiency Speaker Asylum, any current source for old RCA product info online? (0.00)
Posted by maxhifi on 2016-02-24, 09:31:56 (198.233.141.11)
Probably you guys remember the former Oswald Mills RCA archive... is there any current online source for that info? I am looking for the sound products catalogs, as well as the data sheets they had on .......
247: Tubes Asylum, RE: McINTOSH MC-30 & FISHER 90-C REBUILD by MIKE SAMRA (0.00)
Posted by maxhifi on 2016-02-24, 06:24:46 (206.75.129.36)
This man puts his money where his mouth is, look at all those Russian PIO capacitors. Can't wait to try mine when they show up! How do you find you like using two mono preamp? I have thought about it, .......
248: Tubes Asylum, RE: Let me ask this question another way (0.00)
Posted by maxhifi on 2016-02-23, 10:16:30 (198.233.141.11)
Seriously? That is terrible. I have seen some of their stuff reverse engineered, and they do seem to do things like exceed the maximum input filter capacitor size on rectifier tubes. All the same, tu .......
249: Tubes Asylum, RE: Let me ask this question another way (0.00)
Posted by maxhifi on 2016-02-23, 07:32:21 (198.233.141.11)
3500 hours? Consider getting a spare Set of tubes to gave on hand. Keep them clean inside and out Get a schematic and check voltages with a high impedance volt meter like a DMM after amps have warmed .......
250: Tubes Asylum, RE: ANY us made old stock 6SN7 will be a vast improvement (0.00)
Posted by maxhifi on 2016-02-20, 10:23:17 (206.75.129.36)
I have a couple old TVs I restored, philco predicta for example... nobody is going to argue that tube video looks better but it's fun to work on, and I like watching it. The predicta even came with a .......
251: Tubes Asylum, RE: ANY us made old stock 6SN7 will be a vast improvement (0.00)
Posted by maxhifi on 2016-02-19, 10:54:36 (198.233.141.11)
That tube on the left, is a GE, can't see markings on the other. Those were super plentiful in 1950s televisions. .......
252: Tubes Asylum, RE: Why fool around with NP 6SL7s when you can buy Tung-Sol roundplates? (0.00)
Posted by maxhifi on 2016-02-18, 15:08:10 (198.233.141.11)
A few? I'd say so :) Open market value is tending towards stratosphere, but these definitely check all the boxes for what one wants from a tube. .......
253: Tubes Asylum, RE: Why fool around with NP 6SL7s when you can buy Tung-Sol roundplates? (0.00)
Posted by maxhifi on 2016-02-18, 14:14:46 (198.233.141.11)
Now those are cool... really like the RCA logo. I have some "special red" 6SJ7s which have a similar premium look to them, and great performance too. Kind of like getting the well aged whiskey in a ni .......
254: Tubes Asylum, RE: Why fool around with NP 6SL7s when you can buy Tung-Sol roundplates? (0.00)
Posted by maxhifi on 2016-02-17, 10:01:54 (198.233.141.11)
Because $63.99 plus $29 shipping is nearly $100 USD for a pair of *used* tubes, which may end up having a cathode to heater short, or less life in them than claimed. I just don't see it as a responsib .......
255: Tubes Asylum, RE: 6SL7 - your experience with the Russian tubes? (0.00)
Posted by maxhifi on 2016-02-14, 20:25:12 (174.90.222.184)
Oh, I meant the svetlana factory in st Petersburg and their soviet era production, not Their 21st century products. Although I did have a set of their pre new sensor EL34s in the late 1990s and was im .......
256: Tubes Asylum, is this an RCA made tube? (0.00)
Posted by maxhifi on 2016-02-14, 09:57:40 (174.90.222.184)
If so I put together a pair... Both are identical except labels, one says Rogers the other GE, but based on looking at pictures online they appear to be RCA. Good sound too. .......
257: Tubes Asylum, RE: 6SL7 - your experience with the Russian tubes? (0.00)
Posted by maxhifi on 2016-02-14, 06:10:55 (174.90.222.184)
Hi Ivan, Thank you very much for your overview! I have some experience with Russian tubes and equipment, so I am not totally a stranger to the fact that the USSR produced some excellent equipment. I h .......
258: Tubes Asylum, RE: 6SL7 - your experience with the Russian tubes? (0.00)
Posted by maxhifi on 2016-02-13, 17:19:17 (70.28.245.54)
I was looking at the widely distributed reflector version, but now that I see this one I kind of want to try it, I like how it looks already. What was the name of the Moscow factory? I will have to lo .......
259: Tubes Asylum, RE: 6SL7 - your experience with the Russian tubes? (0.00)
Posted by maxhifi on 2016-02-12, 13:18:25 (174.90.223.14)
That's what I thought too, but antique electronic supply wants $30 for a NOS 6SL7 now! And prices on eBay are nuts too... Last time I bought them I paid about $6.00 each. That's why I am looking into .......
260: Tubes Asylum, RE: I'm interested for Ampeg B-15 (0.00)
Posted by maxhifi on 2016-02-12, 10:39:25 (198.233.141.11)
How come not for hi-fi? It's not a lot different than a 12AX7 performance wise, especially if you aren't using it in a low noise application. .......
261: Tube DIY Asylum, Better rectifier tubes (0.00)
Posted by maxhifi on 2016-02-12, 09:14:58 (198.233.141.11)
Was thinking about concerns regarding the ratings of the rectifier tube. Although the GE tubes in the amplifier continue to work well, I am thinking about what can be done to improve matters. Looks l .......
262: Tubes Asylum, 6SL7 - your experience with the Russian tubes? (0.00)
Posted by maxhifi on 2016-02-12, 07:52:38 (198.233.141.11)
Want to get some new 6SL7 tubes for my old RCA amplifiers, and am thinking to try the Russian ones, due to their excellent price but for one concern. I restored another RCA amplifier some time back w .......
263: Tube DIY Asylum, RE: Advice on safe troubleshooting method please (0.00)
Posted by maxhifi on 2016-02-11, 06:03:51 (206.75.129.36)
With this sort of problem, one method I like to employ is to apply power slowly through a variac, closely monitoring AC current draw with a kill a watt. And checking voltages. If something is drawing .......
264: Tube DIY Asylum, RE: You don't want the atoms (0.00)
Posted by maxhifi on 2016-02-10, 21:33:06 (206.75.129.36)
What do you think of the old standby Philips/BC components/Vishay capacitors? The axial ones with the translucent blue plastic insulation, which have looked the same since the late 60s. .......
265: Tube DIY Asylum, RE: I just saw the amps like the ones you have. (0.00)
Posted by maxhifi on 2016-02-10, 21:27:41 (206.75.129.36)
The 5R4 is the only common rectifier capable of handling the voltage of the power transformer, which is really high due to the choke input filter. Here's a picture of them. The non matching plate c .......
266: Tube DIY Asylum, RE: What capacitors to buy to refurbish old RCA amp? (0.00)
Posted by maxhifi on 2016-02-10, 16:00:44 (206.75.129.36)
Nice collection! I didn't realize the round output transformers were that limited, I've wanted something including them for a long time - my MI-12188a's are very wide range. I also have an MI-12202B w .......
267: Tube DIY Asylum, RE: What capacitors to buy to refurbish old RCA amp? (0.00)
Posted by maxhifi on 2016-02-10, 13:06:33 (198.233.141.11)
My plan is to let them sit at 400VDC with a bench power supply and measure leakage with my Simpson 260 on the 50uA scale, before I go ahead and put them into the amplifiers. I don't have an actual cap .......
268: Tube DIY Asylum, RE: What capacitors to buy to refurbish old RCA amp? (0.00)
Posted by maxhifi on 2016-02-10, 12:36:57 (198.233.141.11)
I have had many of these leaky brand new (NOS) the paper in oil? I plan on testing them each for leakage before use .......
269: Tube DIY Asylum, RE: What capacitors to buy to refurbish old RCA amp? (0.00)
Posted by maxhifi on 2016-02-10, 12:24:45 (198.233.141.11)
The feedback configuration threw me for a loop at first too (no pun intended!) Especially the little trick they used to bias the first 6SL7 section properly. DC current flows through the feedback resi .......
270: Tube DIY Asylum, RE: What capacitors to buy to refurbish old RCA amp? (0.00)
Posted by maxhifi on 2016-02-10, 10:01:47 (174.90.222.193)
I ordered ten k40y-9 0,1uf 400V capacitors for the 0.1's, and two 0.5uf 1000V KBG-MN bathtub paper in oils for the 0.5uf capacitors. They have the look I want and are exactly the value of originals. .......
271: Tube DIY Asylum, RE: What capacitors to buy to refurbish old RCA amp? (0.00)
Posted by maxhifi on 2016-02-10, 08:10:27 (198.233.141.11)
Long term relationship? I would definitely owe them some major alimony if I decided to move on.. I've had other amplifiers in and out of my system but prefer the sound and power of the RCAs. I like t .......
272: Tube DIY Asylum, RE: What capacitors to buy to refurbish old RCA amp? (0.00)
Posted by maxhifi on 2016-02-10, 07:40:21 (198.233.141.11)
Thank you for this, looks like Mouser has a good selection of CDE WMF. and unlike the Soviet caps these ones are not 25 years old NOS. .......
273: Tube DIY Asylum, RE: What capacitors to buy to refurbish old RCA amp? (0.00)
Posted by maxhifi on 2016-02-10, 07:39:17 (198.233.141.11)
Thank you for your experience! I too have had good luck with Panasonic capacitors, having used them in several restorations and construction projects. Actually I usually go with Panasonic as my first .......
274: Tube DIY Asylum, RE: What capacitors to buy to refurbish old RCA amp? (0.00)
Posted by maxhifi on 2016-02-10, 07:36:15 (198.233.141.11)
Those are all attractive looking options. My only worry with the Russian ones, is that they are already 25 years old. Maybe they can last a long time, but I have some experience repairing Soviet made .......
275: Tube DIY Asylum, RE: What capacitors to buy to refurbish old RCA amp? (0.00)
Posted by maxhifi on 2016-02-10, 07:34:15 (198.233.141.11)
Those look like a good substitute for orange drops. I also repair old radios and may have to try some in that application too. .......
276: Tube DIY Asylum, RE: What capacitors to buy to refurbish old RCA amp? (0.00)
Posted by maxhifi on 2016-02-10, 07:32:42 (198.233.141.11)
I heard they moved production to China, and also, they have radial leads, designed for PC boards, instead of axial leads like something from 1951 would have. Otherwise I've heard only good things too, .......
277: Tube DIY Asylum, RE: What capacitors to buy to refurbish old RCA amp? (0.00)
Posted by maxhifi on 2016-02-10, 06:24:57 (206.75.129.36)
Here Is the original RCA schematic - I was lucky to get the instructions with my amp. The one you have is based on reverse engineering, and isn't completely correct. There is global feedback here, .......
278: Tube DIY Asylum, What capacitors to buy to refurbish old RCA amp? (0.00)
Posted by maxhifi on 2016-02-09, 16:58:34 (198.233.141.11)
Figured it's time to refurbish my old RCA mono amplifiers (MI-12188A). These are rather large 70W PPP 807 amplifiers, with a big choke input power supply, and regulated screen supply. Right now the c .......
279: Vinyl Asylum, RE: Clearaudio Aurum Classics Wood - what to do? (0.00)
Posted by maxhifi on 2015-12-11, 08:25:30 (184.151.222.120)
So reading more on the subject I learned the audio technica p mount stylii will also fit. I happened to have an old AT92E which I got as an emergency spare some years ago. I trimmed back the plasti .......
280: Vinyl Asylum, RE: Clearaudio Aurum Classics Wood - what to do? (0.00)
Posted by maxhifi on 2015-12-09, 19:47:45 (206.75.129.36)
Good point! The Maestro looks like an impressive cartridge, really on the top end of the MM world. I am not suggesting Clearaudio is selling a $50 cartridge for $500, I am more interested in what sort .......
281: Vinyl Asylum, RE: Clearaudio Aurum Classics Wood - what to do? (0.00)
Posted by maxhifi on 2015-12-09, 13:43:18 (198.233.141.11)
It is more than a visual similarity, many people report success installing an AT95E stylus in a Clearaudio body I even watched a guy do the work on youtube.. looks easy enough. However, I don't want a .......
282: Vinyl Asylum, Clearaudio Aurum Classics Wood - what to do? (0.00)
Posted by maxhifi on 2015-12-09, 09:35:33 (198.233.141.11)
I have one I got back in 2008 for my emotion/satisfy. I decided to try another cartridge, and removed the aurum classics wood - set it down beside my turntable, perhaps for an hour or two. The cat dec .......
283: High Efficiency Speaker Asylum, RE: La Scala (0.00)
Posted by maxhifi on 2015-04-09, 09:27:55 (184.70.169.107)
La Scalas Update: I thought I should come back here some months later, and do a follow up. I picked up the La Scalas back in December. At first I was using them with a low powered 2A3 amplifier, and .......
284: High Efficiency Speaker Asylum, RE: Consider RCA Surround less driver (0.00)
Posted by maxhifi on 2014-12-22, 12:07:55 (184.70.169.107)
Always been curious about those - they're heavily featured in old 50s era books. What kind of enclosure do you use? Note: Given prices they have been reaching lately (yes I have been watching), I woul .......
285: High Efficiency Speaker Asylum, Free lunch ? (0.00)
Posted by maxhifi on 2014-12-15, 12:59:41 (184.70.169.107)
Is it possible you are expecting a free lunch? Compact size, high efficiency, good bass response - you can only have two at a time, there's no way around this. The midrange peak sounds like cone break .......
286: High Efficiency Speaker Asylum, RE: Fostex fx-120 (0.00)
Posted by maxhifi on 2014-12-15, 10:02:37 (184.70.169.107)
My solution to the "little fingers" thing has been to leave delicate things all over the place, and take the time to describe what is delicate and why. Never had any damage to anything from children. .......
287: High Efficiency Speaker Asylum, RE: Fostex fx-120 (0.00)
Posted by maxhifi on 2014-12-15, 09:23:43 (184.70.169.107)
My Bedroom system is a Sony clock radio... I think an upgrade may be in order. What does the back of those speakers look like? What about enclosures? .......
288: High Efficiency Speaker Asylum, RE: Klipsch La Scala Restoration/modification (0.00)
Posted by maxhifi on 2014-12-15, 08:56:05 (184.70.169.107)
I haven't had a ton of free time since getting the new speakers set up... so far I have only used them with my single ended 2A3 amplifier, and it literally can be heard from every corner of my 1350 sq .......
289: High Efficiency Speaker Asylum, RE: Klipsch La Scala Restoration/modification (0.00)
Posted by maxhifi on 2014-12-12, 11:23:22 (184.70.169.107)
I have to say, I am on an earlier point of the curve than some of you guys here. To me the midrange of the La Scala was a strong selling point I definitely love the way the K400 horns project such an .......
290: High Efficiency Speaker Asylum, Klipsch La Scala Restoration/modification (0.00)
Posted by maxhifi on 2014-12-12, 10:10:23 (184.70.169.107)
After exhausting everyone's opinions on which high efficiency speakers to buy, I ended up bringing a pair of 1981 vintage La Scalas into my listening room. Giving them a frequency sweep showed up some .......
291: High Efficiency Speaker Asylum, First impressions (0.00)
Posted by maxhifi on 2014-12-11, 22:38:48 (68.148.189.116)
Finally got some help to get the monsters to the basement, and set them up. These are some very unique speakers! First off the filament supply in my 2A3 amplifier is very inadequately filtered. Seco .......
292: High Efficiency Speaker Asylum, RE: Sobering (0.00)
Posted by maxhifi on 2014-12-10, 10:53:15 (184.70.169.107)
Jamie Just wanted to thank you for all your insight into the speaker situation! As you can see after research and consideration I did end up going with the la scalas. Why? 1. Price, it's an all in so .......
293: High Efficiency Speaker Asylum, RE: got them! (0.00)
Posted by maxhifi on 2014-12-10, 08:46:02 (174.90.222.167)
With the citation Ii powering then and sat in corners the bass was not particularly wanting. I guess it's a matter of expectations, I have a Triad powered sub for my home theatre (a 12 in a heavy seal .......
294: High Efficiency Speaker Asylum, RE: La Scala (0.00)
Posted by maxhifi on 2014-12-10, 08:33:35 (184.70.169.107)
Thank you for the above story! I think I will re-visit this thread in a year or two once I am familiar with the stock speakers, and am seeking a new level of performance. Right now I am way too amaze .......
295: High Efficiency Speaker Asylum, got them! (0.00)
Posted by maxhifi on 2014-12-10, 07:32:26 (68.148.189.116)
The seller had a Harmon kardon Citation II and HK tube preamp hooked up to a Thorens. It didn't take me very long to realize these speakers are apecial! These have the AA networks rebuilt with sonica .......
296: High Efficiency Speaker Asylum, MOMENT OF TRUTH (0.00)
Posted by maxhifi on 2014-12-09, 13:30:07 (184.70.169.107)
Going to go check them out tonight - here`s hoping for the best! Thank you everyone for your contributions! -Max .......
297: High Efficiency Speaker Asylum, RE: LaScala copies (0.00)
Posted by maxhifi on 2014-12-08, 17:10:01 (184.70.169.107)
how much? .......
298: High Efficiency Speaker Asylum, RE: Sobering (0.00)
Posted by maxhifi on 2014-12-06, 14:30:21 (184.70.112.38)
Hey Jamie! I am out of town for an office Christmas party this weekend, wi-fi here is horrible! Not close to sober yet, thank you very much for all the advice! I have to say I am envisioning a setup .......
299: High Efficiency Speaker Asylum, RE: I can't seem to find a good frequency response plot for the La Scalas (0.00)
Posted by maxhifi on 2014-12-06, 13:56:16 (184.70.112.38)
$1700 CDN is the asking price I would probably offer a maximum of $1500 I am out of the city for the weekend, will respond to all the awesome feedback tomorrow evening .......
300: SET Asylum, RE: Why waste the time? (0.00)
Posted by maxhifi on 2014-12-05, 09:30:33 (184.70.169.107)
Just to play the devil's advocate, how about designs like Doug Self's Blameless amplifier, which literally has almost no measureable distortion, and more or less ideal square wave response? I appreci .......
301: High Efficiency Speaker Asylum, RE: La Scala (0.00)
Posted by maxhifi on 2014-12-05, 08:58:12 (184.70.169.107)
It's only crass to talk about money when it isn't relevant. (And yea I am the type of Canadian who will become offended if someone directly asks my income!) The la scalas are black and the guy is aski .......
302: SET Asylum, JJ tubes arrived! (0.00)
Posted by maxhifi on 2014-12-04, 21:47:58 (68.148.189.116)
First, fhese are some visually impressive tubes! Open the box and there is an individual test sheet with a serial number on it. Under a piece of foam is the tube itself, sparkling clean and not a m .......
303: High Efficiency Speaker Asylum, RE: La Scala (0.00)
Posted by maxhifi on 2014-12-04, 19:14:10 (68.148.189.116)
Hey Jamie, Now you have me second guessing myself! Are the la scalas really that bad? The polarization of opinions online made me want to hear them, I haven't pushed "go" yet, but I figured a product .......
304: High Efficiency Speaker Asylum, RE: La Scala (0.00)
Posted by maxhifi on 2014-12-04, 15:47:42 (70.28.245.29)
See link - no personal experience but read good things online .......
305: High Efficiency Speaker Asylum, RE: La Scala (0.00)
Posted by maxhifi on 2014-12-04, 14:58:25 (184.70.169.107)
Hey Bob Different La Scalas, am not anywhere near to you geographically. In other words, we are not competing... go get those ones and we can compare notes :) -Max .......
306: High Efficiency Speaker Asylum, RE: La Scala (0.00)
Posted by maxhifi on 2014-12-04, 13:33:54 (184.70.169.107)
Hi Moray, Thank you for your response! I was actually reading about the riser mod at the attached link just before I read your message, and it looks like an absolutely decent project. I really like th .......
307: High Efficiency Speaker Asylum, RE: La Scala (0.00)
Posted by maxhifi on 2014-12-04, 13:11:09 (184.70.169.107)
My systems are all analog and all tubes. Hum is more or less a non issue with the Priboi and the Dynaco amplifiers, but the SET and the RCA's may need a little tune up. Going to go see the speakers on .......
308: High Efficiency Speaker Asylum, RE: La Scala (0.00)
Posted by maxhifi on 2014-12-04, 09:38:04 (70.28.245.29)
I have a few I want to try 1. Single ended triode (2A3) with EF37A driver and Sowter output transformer (self made) 2. RCA MI-12188a mono amplifiers (push pull parallel 807) 3. 75W Priboi amplofier ( .......
309: High Efficiency Speaker Asylum, La Scala (0.00)
Posted by maxhifi on 2014-12-04, 08:28:58 (184.70.169.107)
Going to take a look at 1981 vintage La Scalas, with the Bob Crites upgraded AA crossover. I have a room which is 30 x 14 with an 8 foot ceiling, acoustic tile ceiling and carpet floor. Would put the .......
310: High Efficiency Speaker Asylum, RE: RCA fan ? (0.00)
Posted by maxhifi on 2014-12-03, 16:12:49 (184.70.169.107)
Ahh looks like I misinterpreted what was meant by RCA fan .......
311: High Efficiency Speaker Asylum, RE: Pro audio look for vintage Altec EV JBL etc (0.00)
Posted by maxhifi on 2014-12-03, 14:25:47 (184.70.169.107)
You sir, have shown a photo of a 1956 gullwing Mercedes to someone with the budget for a Mazda Miata... of course, a lot of fun can be had with a Miata too, so all is not lost. That RCA setup looks sp .......
312: High Efficiency Speaker Asylum, RE: I never met a (0.00)
Posted by maxhifi on 2014-12-03, 09:07:41 (184.70.169.107)
I have some Traynor PA columns which are very very loud, but not much else. And you're right... I have certainly never been blown away by the sound of the 12 - 15" woofer plus a horn type systems when .......
313: High Efficiency Speaker Asylum, RE: Klipsch Cornwall II (0.00)
Posted by maxhifi on 2014-12-03, 09:04:02 (184.70.169.107)
This really is a commonly recommended speaker... I could easily accommodate a pair in my listening room, and unlike many other options they don't appear to be bass deficient. I think resale wouldn't b .......
314: High Efficiency Speaker Asylum, RE: Yorkville pro sound speakers for SET ? (0.00)
Posted by maxhifi on 2014-12-03, 09:01:24 (184.70.169.107)
Thank you! I won't waste my time - the specs seemed too good to be true, but I am trying to look at ALL my options. Basically I love the sound of my recently completed 2A3 amplifier, but it really run .......
315: High Efficiency Speaker Asylum, RE: RCA fan ? (0.00)
Posted by maxhifi on 2014-12-03, 08:57:36 (184.70.169.107)
A pair of RCA SL-12's just went on eBay for some serious $$ for 60 year old speakers I have never heard. I was hoping that I could get some SL-12 or SL-8 for a half decent price but not happening on e .......
316: High Efficiency Speaker Asylum, RE: Do keep in mind pricing is per 'each', not per 'pair'... (0.00)
Posted by maxhifi on 2014-12-02, 21:01:10 (68.148.189.116)
Hi Paul, Thank you for reminding me that your company's website has an excellent section on efficient speakers. I read it years ago before I actually had a triode amp and was ready to buy something, .......
317: High Efficiency Speaker Asylum, RE: Do keep in mind pricing is per 'each', not per 'pair'... (0.00)
Posted by maxhifi on 2014-12-02, 19:40:51 (68.148.189.116)
The Cornwall on paper looks like an excellent choice, my only reservation is that when I auditioned a pair of heresy III's quite recently (admittedly not a Cornwall) I found them to have a certain box .......
318: High Efficiency Speaker Asylum, RE: At the risk of being run out of town on a rail.... (0.00)
Posted by maxhifi on 2014-12-02, 15:03:13 (184.70.169.107)
No I have not - looks like they have a lot of options, the DIY ones are quite cost effective too! That 8pi looks like a formidable beast .......
319: High Efficiency Speaker Asylum, RE: Yorkville pro sound speakers for SET ? (0.00)
Posted by maxhifi on 2014-12-02, 14:12:32 (184.70.169.107)
"Most prosound speakers today are designed for very high power use. This means that the horn tweeter has to be crossed very high, around 2200hz for example. Consequently, the woofer (often 12") is use .......
320: High Efficiency Speaker Asylum, RE: Yorkville pro sound speakers for SET ? (0.00)
Posted by maxhifi on 2014-12-02, 12:31:09 (184.70.169.107)
The ones I see are used, it's just a classified ad. I am just fishing for some opinions on weather or not this is a direction which may be worth pursuing. (99dB/W and smooth response 60 Hz - 20KHz is .......
321: High Efficiency Speaker Asylum, Yorkville pro sound speakers for SET ? (0.00)
Posted by maxhifi on 2014-12-02, 08:28:09 (70.28.245.29)
Been looking for some speakers for my single ended triode setup, and need someone to tell me why this idea is bad. After searching for suitable speakers here comes the yorkvilles yX12c The specs are .......
322: High Efficiency Speaker Asylum, RE: How to raise the total resistance of a speaker (0.00)
Posted by maxhifi on 2014-12-01, 20:55:56 (68.148.189.116)
What an awesome anplifier to own, yes of course I was making a generalization, I am not sure what mechanism limits current in the Pass amp but it doesn't matter, that is clearly a very specialized (an .......
323: SET Asylum, RE: OPT as Impedence Matching Device (0.00)
Posted by maxhifi on 2014-12-01, 20:27:56 (68.148.189.116)
Hi Jamie, I have two comments on the above analogy 1. consider that this analogy avoids one fact Volts = speed of truck Amps = weight of load Ohms = height of hill Play with the three variables and yo .......
324: SET Asylum, RE: JJ 2A3-40 (0.00)
Posted by maxhifi on 2014-11-30, 20:43:42 (68.148.189.116)
I looked at the curves before I hit "buy" Is your nickname on here a wireless world reference? If so that's pretty cool. .......
325: High Efficiency Speaker Asylum, RE: JE Labs Baffles - SPL from SET? (0.00)
Posted by maxhifi on 2014-11-30, 11:14:30 (68.148.189.116)
I used to have a pair of Goodmans Triaxiom speakers and felt exactly the same about the discontinuity between bass and treble. I had mine in washing machine sized cabinets, and despite their excellent .......
326: SET Asylum, RE: if money wasn't a consideration... (0.00)
Posted by maxhifi on 2014-11-30, 10:09:40 (68.148.189.116)
I will make a mechanical analogy which may help you understand this topic a little bit. Voltage can be compared to speed, and current to torque, and an output trabsformer and a transmission have about .......
327: SET Asylum, RE: 32 Ohm Drivers // 32 Ohm OPTs (0.00)
Posted by maxhifi on 2014-11-28, 16:01:44 (68.148.189.116)
Far from screwed - go series parallel and if you want to be anally retentive about it measure the Fs of each driver and match them accordingly : say that A and B are in parallel, and C and D are in pa .......
328: SET Asylum, RE: 32 Ohm Drivers // 32 Ohm OPTs (0.00)
Posted by maxhifi on 2014-11-28, 14:05:46 (184.70.169.107)
I'm not in the audio industry, I wouldn't challenge the opinion of a famous active crossover manufacturer. My response was directed towards using the speakers full range, with resonance inside the pa .......
329: SET Asylum, RE: 32 Ohm Drivers // 32 Ohm OPTs (0.00)
Posted by maxhifi on 2014-11-28, 13:49:31 (184.70.169.107)
If you are not using the drivers anywhere near their resonant frequency, then it's a non-issue. They should match fairly well above this frequency, and any anomalies below the crossover frequency won' .......
330: SET Asylum, RE: 32 Ohm Drivers // 32 Ohm OPTs (0.00)
Posted by maxhifi on 2014-11-28, 12:57:46 (184.70.169.107)
Well, first off, I made a mistake, it is actually going to reduce power to 50%, not 25%. (I was for some reason thinking we were halving the voltage rAnd it may be a little more than 50% since the hig .......
331: SET Asylum, RE: 32 Ohm Drivers // 32 Ohm OPTs (0.00)
Posted by maxhifi on 2014-11-28, 12:20:00 (184.70.169.107)
If you use a 32 ohm speaker on a 16 ohm tap, it can reduce the power output from the amplifier to 25% of the rated value. If they are very efficient speakers, this may not matter. Also, if the speaker .......
332: SET Asylum, RE: 32 Ohm Drivers // 32 Ohm OPTs (0.00)
Posted by maxhifi on 2014-11-28, 12:00:31 (184.70.169.107)
Just out of curiosity, why not just wire the same four drivers to get a lower impedance instead? .......
333: SET Asylum, RE: Wrong forum? (0.00)
Posted by maxhifi on 2014-11-28, 11:58:17 (184.70.169.107)
"How much are the Cornwalls you know about?" $2700 CDN, and the seller makes note of them being Cornwall III. If it was a cheap pair of first gen I would call it a no brainer, but this is way too much .......
334: High Efficiency Speaker Asylum, RE: Goodmans 201 with a T35B capped in at about 6KHz? (0.00)
Posted by maxhifi on 2014-11-28, 11:29:57 (184.70.169.107)
I just sold some goodmans speakers earlier this year! I had them in my basement for 20 years and sold them to make space shortly before getting into SETs... let it be known, never sell anything! haha .......
335: SET Asylum, RE: Wrong forum? (0.00)
Posted by maxhifi on 2014-11-28, 11:26:35 (184.70.169.107)
Yeah, I am thinking JE Labs baffle with some as yet unknown driver... it will get me started with a minimal investment. Don't want to lock in to some high dollar horn system just yet. Already posted o .......
336: High Efficiency Speaker Asylum, How about the audio nirvana speakers? (0.00)
Posted by maxhifi on 2014-11-28, 11:02:17 (184.151.222.117)
Anyone tried them? Look to be perfect but the Advertising style isn't very Appealing, way too much bragging going on. .......
337: High Efficiency Speaker Asylum, JE Labs Baffles - SPL from SET? (0.00)
Posted by maxhifi on 2014-11-27, 14:22:32 (184.70.169.107)
I am just getting in to the single ended triode thing, and need to get some speakers which will generate some "SPLs" from a SET amplifier. Specifically, around 2W RMS output from a 2A3. My attraction .......
338: High Efficiency Speaker Asylum, RE: How to raise the total resistance of a speaker (0.00)
Posted by maxhifi on 2014-11-27, 13:28:49 (184.70.169.107)
The reason why there aren't many high impedance speakers, is that when you use a solid state amplifier (as most people do), the amplifier will deliver less power into a higher impedance speaker. A hig .......
339: SET Asylum, RE: Wrong forum? (0.00)
Posted by maxhifi on 2014-11-27, 08:11:28 (68.148.189.116)
And herein lies the hard part. Locally there's some Altec 755c's in JE labs style baffles for sale, there's some klipsch la scales for more money, and some Cornwalls. I haven't read the entire Fostex .......
340: SET Asylum, RE: Wrong forum? (0.00)
Posted by maxhifi on 2014-11-26, 20:03:05 (68.148.189.116)
I saw an alarming statistic recently about what percentage of North Americans believe in ghosts, it was mind blowing how high it was! That said if ghosts did exist I doubt you would be the only one :) .......
341: SET Asylum, RE: Wrong forum? (0.00)
Posted by maxhifi on 2014-11-26, 17:52:06 (68.148.189.116)
I have to say I have always been a committed push pull guy - testing the amplifier last night and seeing it clip asymmetrially, as the grid started drawing current and drag down the driver was really .......
342: SET Asylum, RE: Unfortunately it's too later to change the impedance (0.00)
Posted by maxhifi on 2014-11-26, 17:46:50 (68.148.189.116)
I actually did have that in mind when I first built it in 2006, the driver stage was inspired by a Japanese 45 amp. I went with the 2A3 becasuse they are available new. With the JJs on the way I am mo .......
343: SET Asylum, RE: Unfortunately it's too later to change the impedance (0.00)
Posted by maxhifi on 2014-11-26, 15:47:45 (184.70.169.107)
Yes, I certainly could give that a try. The only reason I haven't gone down that path, is the transformer will be more lossy that way. Us engineers can tend to hit a mental road block when entering th .......
344: SET Asylum, Wrong forum? (0.00)
Posted by maxhifi on 2014-11-26, 15:37:08 (184.70.169.107)
The fact that everything I have asked about has nearly immediately generated an extremely helpful and useful response, has sort of told me I am in the right place. To be honest I am enjoying having ac .......
345: SET Asylum, Unfortunately it's too later to change the impedance (0.00)
Posted by maxhifi on 2014-11-26, 15:22:17 (174.90.223.218)
I orginally bought these transformers for a single ended EL84 project. I put this amplifier together using things I already had on hand, to get a taste of what real triodes are capable of. If doing it .......
346: SET Asylum, RE: Dropping the Power Stage (0.00)
Posted by maxhifi on 2014-11-26, 13:57:29 (184.70.169.107)
That amplifier looks like a real beauty, I saw it on trader - nice buy .......
347: SET Asylum, RE: 2A3 Actuals (0.00)
Posted by maxhifi on 2014-11-26, 13:43:20 (184.70.169.107)
Hi Jeff As per my above post, I think your operating point is probably not only best empirically, but it does seem to look the best theoretically too, given my other constraints. Looks like the bes .......
348: SET Asylum, RE: 2A3 Actuals (0.00)
Posted by maxhifi on 2014-11-26, 13:35:36 (184.70.169.107)
I think the JJ 2A3s I bought are good for 400V Check out the attachment I added - THD is clearly lower for the higher current (well, as it should be since it's in a more linear part of the curve), .......
349: SET Asylum, RE: 2A3 Actuals (0.00)
Posted by maxhifi on 2014-11-26, 09:59:39 (184.70.169.107)
I must have a phase reversal happening in the output transformer, or it is also possible that I didn't return the "phase" knob on my scope to "normal" between tests. The clipping behaviour is definite .......
350: SET Asylum, 2A3 Actuals (0.00)
Posted by maxhifi on 2014-11-26, 09:36:20 (184.70.169.107)
Last night I decided to have some fun on the bench.. I connected my 2A3 amplifier to an 8 ohm dummy load, and fed it with a signal from my audio oscillator. I used 60Hz, just so that my DMM would be c .......
351: SET Asylum, RE: 2A3 Operating Points (0.00)
Posted by maxhifi on 2014-11-25, 13:00:04 (184.70.169.107)
Hi Paul, This looks like a decent operating point P = 3.5W H2 = 7.6% H3 = 1% RL = 5.1k B+ = 360V VG1 = -60V If I can raise my B+ to 375V as per your design, it will more than double power output. It .......
352: SET Asylum, RE: RCA 5691 Red Base Tubes (0.00)
Posted by maxhifi on 2014-11-25, 11:32:19 (184.70.169.107)
Looks like a special 6SL7, would be a voltage amplifier for audio Sell them to these guys and go on vacation :) https://www.tubeworld.com/5691.htm .......
353: SET Asylum, RE: 2A3 Operating Points (0.00)
Posted by maxhifi on 2014-11-25, 11:30:11 (184.70.169.107)
When I have designed amplifiers previously, I relied 100% on hand written calculations and my TI-85 pocket calculator... this seems to add a whole new dimension to what is possible. I am an EE, but ha .......
354: SET Asylum, RE: 2A3 Operating Points (0.00)
Posted by maxhifi on 2014-11-25, 11:21:17 (184.70.169.107)
Wow! CAD for tube amplifiers, who knew! Thank you!! .......
355: SET Asylum, 2A3 Operating Points (0.00)
Posted by maxhifi on 2014-11-25, 11:03:16 (184.70.169.107)
While I wait for my eagerly anticipated and democratically chosen JJs to show up, I want to do a little bit of analysis and see what I have bought and how it can best be used. I plan to use mine with .......
356: SET Asylum, RE: Getting back to what Dennis said.... (0.00)
Posted by maxhifi on 2014-11-25, 08:14:54 (68.148.189.116)
This luckily is not a problem of philosophy but rather a technical one. if the lower portion of the wave is driving the tube into cutoff, you will also get more distortion and less output. The bias po .......
357: SET Asylum, RE: Dropping the Power Stage (0.00)
Posted by maxhifi on 2014-11-25, 07:31:36 (68.148.189.116)
If you want to try some unconventional tubes, there are some things to look for. The triode curves should have a small bend at the low end and fhen be almost perfectly straight, with even Spacing betw .......
358: SET Asylum, RE: Second Hand Testimonial from someone Experienced (0.00)
Posted by maxhifi on 2014-11-24, 18:55:39 (68.148.189.116)
Hi Jeff, I must have read your mind - AES has been my preferred vendor For over 20 years now, the Sale just solidified their place. My output transformers (sowter sa02) are good for 45mA and I have 28 .......
359: SET Asylum, THANK YOU ALL - I ORDERED THE JJ 2A3-40 (0.00)
Posted by maxhifi on 2014-11-24, 18:31:45 (68.148.189.116)
On sale at antique electronic supply, went for a matched pair... can't wait for them to show up! .......
360: SET Asylum, RE: original H plate (0.00)
Posted by maxhifi on 2014-11-24, 13:50:15 (184.70.169.107)
Hmmm digging deeper it looks like the going rate for a pair of used USA 2A3's is around $100, and about double that for a pair of NOS. This is pretty darn competitive with most of the new offerings.. .......
361: SET Asylum, RE: State of the art, or jewelry? New tubes. (0.00)
Posted by maxhifi on 2014-11-24, 13:31:57 (184.70.169.107)
My output transformers apparently cost £285.12 per pair now... Ouch! I am sure I didn't pay quite so much when I ordered them in 2003. I have had very good luck with Sovtek tubes in the past (guitar .......
362: SET Asylum, ebay transformers (0.00)
Posted by maxhifi on 2014-11-24, 13:23:01 (184.70.169.107)
Any ideas what these are? http://www.ebay.com/itm/300B-SE-tube-output-transformer-one-pair-Similar-Western-Electric-171A-for-91A-/121490405993?pt=Vintage_Electronics_R2&hash=item1c49647a69 They sure d .......
363: SET Asylum, State of the art, or jewelry? New tubes. (0.00)
Posted by maxhifi on 2014-11-24, 12:51:41 (184.70.169.107)
So since getting my humble 2A3 amplifier going on the weekend (see my other post), I have been bitten by the SET bug. One item which seems to pop up as a low hanging fruit, in terms of improvements, a .......
364: SET Asylum, RE: Dropping the Power Stage (0.00)
Posted by maxhifi on 2014-11-24, 11:58:29 (184.70.169.107)
Late to the party here, but I will throw in my two cents as you all have been so helpful on my recent posts. This is in essence a bad idea... the driver stage in any amplifier (except where grid curre .......
365: SET Asylum, RE: 'it is not the same tube internally' (0.00)
Posted by maxhifi on 2014-11-23, 14:45:12 (68.148.189.116)
Lots of tubes are different when you wouldn't expect them to be: i.e. 6N7 is different than the 6SN7 the 6Q7 has a lower mu than the 6SQ7 The 6J7 has a lower transconductance than the 6SJ7, and better .......
366: SET Asylum, RE: "6J7 has lower distortion than 6SJ7" (0.00)
Posted by maxhifi on 2014-11-23, 12:07:33 (174.90.222.28)
It's because it is not the same tube internally, it's not related to the grid cap. .......
367: SET Asylum, RE: Clean and simple! (0.00)
Posted by maxhifi on 2014-11-23, 12:06:08 (174.90.222.28)
Have you actually heard these? on paper they look great... It's a shame the second page is included, with te $57/ea banana plugs, it makes me doubt if the speakers are worth their asking price, althou .......
368: SET Asylum, RE: Clean and simple! (0.00)
Posted by maxhifi on 2014-11-23, 11:11:45 (174.90.222.28)
The Heathkit W6M drives the output tubes with a pair of cathode followers, achieving essentially what you are saying, driving power tybe grids with a very low impedance. I have always seen that as a f .......
369: SET Asylum, RE: WECo 91A/B--Additional points and some corrections (0.00)
Posted by maxhifi on 2014-11-23, 10:21:40 (174.90.222.28)
Another awesome post! Thank you again. The RDH4 was my bed time reading for a couple years in the 1990s so that makes a lot of sense that is the source - thanks for the reference! I am now very curio .......
370: SET Asylum, RE: "6J7 has lower distortion than 6SJ7, and it avoids the need for a weird tube socket. " (0.00)
Posted by maxhifi on 2014-11-23, 10:02:35 (174.90.222.28)
Yes, a friend in the UK sent them too me as a gift years ago. I just put them back in the amp... Vesus the RCA 6J7 I have to say the difference if any is sure not obvious. I thought the RCAs sounded b .......
371: SET Asylum, RE: that's not just any front-end tube... (0.00)
Posted by maxhifi on 2014-11-23, 09:31:37 (174.90.222.28)
I didn't define "it" :) What I am referring to is the quantity of information my system is now delivering to my ears, it's like I went from 480p to full HD, using an amplifier which has higher distort .......
372: SET Asylum, RE: that's not just any front-end tube... (0.00)
Posted by maxhifi on 2014-11-23, 08:28:59 (68.148.189.116)
Yes this is true! Although to be honest I am now running it with 1940s metal RCA 6J7 tubes and prefer their sound slightly. I am glad I dusted this thing off and gave it some attention, I had no idea .......
373: SET Asylum, RE: Clean and simple! (0.00)
Posted by maxhifi on 2014-11-22, 21:45:00 (68.148.189.116)
edit: the diodes I used to drop voltage to the 2A3 filaments are drawn backwards... I should proof read before posting! .......
374: SET Asylum, RE: Clean and simple! (0.00)
Posted by maxhifi on 2014-11-22, 20:57:45 (68.148.189.116)
I just drew it out - I lost the original schematic but the power supply is my design. Don't copy how I used diodes to drop voltage to the 2A3 heaters, it would be better to add another RC filter bu .......
375: SET Asylum, 2A3 amplifier - SET Fever (0.00)
Posted by maxhifi on 2014-11-22, 19:57:10 (68.148.189.116)
All my recent interest in the WE91A has motivated me to dig out an amplifier I built back in 2006, and was never satisfied with it. The amplifier is a single ended 2A3 design, using 5000/4-8-16 oh .......
376: SET Asylum, RE: "6J7 has lower distortion than 6SJ7, and it avoids the need for a weird tube socket. " (0.00)
Posted by maxhifi on 2014-11-22, 19:09:04 (68.148.189.116)
I read an article a long time ago, maybe in audio magazine, maybe radio&tv news, to be honest I forget the origin. The author tested all the small signal pentodes, and the conclusion was that the 6J7 .......
377: SET Asylum, RE: WECo 91A/B--Long, but hopefully informative (0.00)
Posted by maxhifi on 2014-11-22, 12:46:51 (68.148.189.116)
Thank you for taking time time to write such a detailed response, it actually is a big help, and it settles some points too. 1. Input tubes will be metal 6J7. 6J7 has lower distortion than 6SJ7, and .......
378: SET Asylum, RE: 6C6 in the WE 91A (0.00)
Posted by maxhifi on 2014-11-22, 09:44:23 (68.148.189.116)
This is really interesting! I think you explained why R41 exists. Also, note that the plate load resistor for v2 in your early version schemaric is 100k versus 90 in the one I posted. Thank you for p .......
379: SET Asylum, RE: WESTERN ELECTRIC 91A CLONE DISCUSSION (0.00)
Posted by maxhifi on 2014-11-22, 09:13:50 (68.148.189.116)
The only one I haven't seen a schematic for yet is Thorsten Loesch's , but by reading his descritption it looks excellent. I think I will be looking at combining elements of all three designs in what .......
380: SET Asylum, RE: WESTERN ELECTRIC 91A CLONE DISCUSSION (0.00)
Posted by maxhifi on 2014-11-22, 09:08:40 (68.148.189.116)
This one looks like one of the most interesting of all from the description, perhaps the truest to the original but unfortunately none of the images work anymore... if anyone would happen to have a sc .......
381: SET Asylum, RE: Consider this DC circuit for 2A3 (0.00)
Posted by maxhifi on 2014-11-21, 23:28:09 (68.148.189.116)
This looks loke a loftin white variant. The 6SF5 is more or less half a 12AX7. I think the down side to this circuit is it needs a huge B+ voltage. Never heard one but it sure looks elegant ... I have .......
382: SET Asylum, RE: A M91 for MG iron (0.00)
Posted by maxhifi on 2014-11-21, 21:38:14 (68.148.189.116)
There is interest here! Would love to see your adaptation Paul. I read the sound practices article before posting here, however I don't feel as though all stones are unturned yet. Several years ago I .......
383: SET Asylum, WESTERN ELECTRIC 91A CLONE DISCUSSION (0.00)
Posted by maxhifi on 2014-11-21, 14:34:16 (184.70.169.107)
Been around the block a few times with audio, but never have owned a 300B amplifier. Have decided to start at the start, and build myself a Western Electric 91A clone. My logic is to start with thi .......
384: High Efficiency Speaker Asylum, RE: Oswald's Mill Website (0.00)
Posted by maxhifi on 2014-06-11, 12:06:24 (184.70.169.107)
It makes me wonder what I am currently taking for granted but should be scrambling to archive! .......
385: High Efficiency Speaker Asylum, RE: Oswald's Mill Website (0.00)
Posted by maxhifi on 2014-06-10, 16:42:58 (184.70.169.107)
Maybe they got tired of the high price of old RCA equipment! .......
386: High Efficiency Speaker Asylum, Oswald's Mill Website (0.00)
Posted by maxhifi on 2014-06-09, 16:32:56 (184.70.169.107)
I come and go from this hobby - recently came back to it and wanted to download some info from the excellent RCA archive at the Oswald's mill website "underground", and found it all gone. Did this stu .......
387: General Asylum, RE: LOL ... (0.00)
Posted by maxhifi on 2013-11-29, 09:55:36 (184.70.169.107)
High end means what you think it means... to me it means equipment built to a performance standard rather than a price, although there's some grey area there too. You should really get out there and .......
388: General Asylum, RE: Joy or danger of picking up/delivering used equipment one buys... (0.00)
Posted by maxhifi on 2013-11-26, 14:44:47 (184.70.169.107)
Buying stuff - go to someone's house, listen to it briefly to confirm it works, hand over exact cash, load the car, and go. Usually the seller will help load the car, and I haven't run into any a-hole .......
389: General Asylum, RE: LOL ... (0.00)
Posted by maxhifi on 2013-11-26, 14:00:51 (184.70.169.107)
Disclaimer: I have a Miata and love it The Miata is a perfect example though of compromise - it does one thing very well, and that thing is handling. On long drives it becomes intolerable from a comfo .......
390: General Asylum, RE: The woes of being a poor audiophile. ;-) (0.00)
Posted by maxhifi on 2013-11-25, 12:50:30 (184.70.169.107)
Be resourceful - Buy used, build from a kit, keep eyes on craigslist and wait for bargains to come up. They can and do come up more or less constantly. A lot of people have more gear than they know wh .......
391: Planar Speaker Asylum, RE: Gotta ask--anyone else using an old Dynaco Stereo 70 with MMGs? (0.00)
Posted by maxhifi on 2013-11-22, 11:42:13 (184.70.169.107)
I use my Magnepan MG-IIB with a Stereo 70/II (Panor version made about 1990) It gets plenty loud for me, I won't change anything any time soon. I am kind of puzzled every time I read that you must hav .......
392: Planar Speaker Asylum, RE: Magnepan MG-IIA rebuild (0.00)
Posted by maxhifi on 2013-11-14, 10:55:03 (184.70.169.107)
I'm about to do this with a pair of MG-IIb, turns out acklands-grainger in Canada does stock 3M Fastbond 30nf, it's just not on their website. Good call about doing it outside, but there's snow on the .......
393: Planar Speaker Asylum, RE: Glue for Magnepan Repair (0.00)
Posted by maxhifi on 2013-10-31, 10:24:48 (184.70.169.107)
This is what Acklands-Grainger has in Canada https://www.acklandsgrainger.com/AGIPortalWeb/WebSource/ProductDisplay/globalProductDetailDisplay.do?item_code=MMM30GN1L Kind of pricy, but seems to only c .......
394: Planar Speaker Asylum, RE: Question for Quad guru's ... (0.00)
Posted by maxhifi on 2013-10-31, 09:54:27 (184.70.169.107)
Unless you use a true sine wave inverter ($$$), this will feed the QUADs power supply transformer with a square wave (BAD!), causing heating in the windings, and possibly making them fail prematurely. .......
395: Planar Speaker Asylum, Glue for Magnepan Repair (0.00)
Posted by maxhifi on 2013-10-31, 09:47:16 (184.70.169.107)
I have an old pair of MG-IIb speakers, and one of the tweeters is dead. I have been doing a lot of reading, and the procedure to repair seems to be fairly well defined at this point in time - looks a .......
396: Tubes Asylum, RE: Vintage Transformer- Good find? (0.00)
Posted by maxhifi on 2013-08-23, 21:24:00 (23.17.38.144)
That looks like a military surplus potted transformer. Who knows what it was made for, likely some cold war type purpose. I really want to visit this "local surplus place" next time I'm in the area if .......
397: Vinyl Asylum, RE: Thorens TD124 - problems after new belt installed (0.00)
Posted by maxhifi on 2012-03-26, 20:25:37 (23.17.36.86)
oil the bearings in the motor my td-124/11 wouldn't move when I got it in the mid 90s due to this issue. .......
398: Tubes Asylum, Works great in Dynaco ST-70/II (0.00)
Posted by maxhifi on 2012-01-31, 18:08:25 (209.89.146.153)
Changed to 90s vintage Sovtek 5881s to "temporarily" replace worn EL34s a few years ago. Provided you can adjust the bias to stay within spec, I say go for it. .......
399: Tubes Asylum, RE: Ok...I'll ask (0.00)
Posted by maxhifi on 2012-01-29, 10:45:43 (209.89.146.153)
To be practical about this topic, if you live in a major city, you can go to a guitar store, and buy most of the audio tubes you will need at a reasonable price. If there's a problem, take them back f .......
400: Vintage Asylum, RE: What is the sound of a crossover that needs new parts? (0.00)
Posted by maxhifi on 2012-01-25, 18:09:00 (209.89.146.153)
Dull or uneven highs I did a frequency sweep with a calibrated mic on some 70s speakers before and after new electrolytic capacitors. Before changing electrolytics highs were down and jagged.... new c .......
401: Tubes Asylum, RE: EH 6C4? (0.00)
Posted by maxhifi on 2010-10-15, 20:39:24 (199.126.230.76)
If the Mullard is noisy, try another one. Noise levels can vary greatly from tube to tube, even if same manufacturer. This is why people pay a premium for tubes selected for low noise for phono stages .......
402: Tape Trail, RE: Sony Cassettes Availability (0.00)
Posted by maxhifi on 2010-05-26, 10:24:10 (200.238.83.49)
I left the store with a smile on my face, goes to show how out of touch I can be with popular culture! I was thinking of saying something easy to relate with, like well, my Mazda has a cassette player .......
403: Tape Trail, RE: Sony Cassettes Availability (0.00)
Posted by maxhifi on 2010-05-26, 09:15:26 (200.238.83.49)
Hey, interesting update. I suspected it had something to do with the website not representing the full range of products. I've never seen any of the Thailand made Sony HF tapes, but will keep my eyes .......
404: Tape Trail, RE: Sony Cassettes Availability (0.00)
Posted by maxhifi on 2010-05-26, 09:07:20 (200.238.83.49)
Here in Edmonton tapes are pretty easy to come by. I just picked up a two pack of TDK "D" at "the source" (radio shack in Canada since 2005) yesterday. London Drugs has Sony and Maxell, and what's lef .......
405: Tape Trail, Sony Cassettes Availability (0.00)
Posted by maxhifi on 2010-05-25, 09:03:50 (200.238.83.49)
I've noticed that all audio cassettes are no longer on the US or Canadian websites - will we see them withdrawn from stores fairly soon also? Just for curiosity I checked the UK, and Japanese website .......
406: Tape Trail, RE: Oh no, where can I get high bias tape!? (0.00)
Posted by maxhifi on 2010-05-20, 08:44:41 (200.238.83.49)
I did read some reviews of these in Hi-Fi World, and they look promising! My only concern is cost, but I guess as high quality cassettes become a specialty product, it's going to become more and more .......
407: Tape Trail, RE: Oh no, where can I get high bias tape!? (0.00)
Posted by maxhifi on 2010-05-20, 08:42:13 (200.238.83.49)
If TDK SA is still being made, it does sound like a good option. TDK has been poorly distributed in Canada, with the majority of stores apparently preferring to sell Maxell. You can find "D" at a few .......
408: Tape Trail, Oh no, where can I get high bias tape!? (0.00)
Posted by maxhifi on 2010-05-19, 15:20:22 (199.126.230.95)
I went to London Drugs to pick up a new box of XL-II, and it's all gone! All they have is normal bias tape, except Fuji DR-II. I have never had good luck with DR-II, neither my Teac nor either of my .......
409: Tube DIY Asylum, If the tube is worth some money may want to buy these (0.00)
Posted by maxhifi on 2009-12-07, 14:00:39 (81.25.172.228)
www.tubesandmore.com part: P-STKY-1 .......
410: Vintage Asylum, RE: Microphonics ... (0.00)
Posted by maxhifi on 2009-11-08, 19:30:08 (199.126.250.124)
I tried a second used 6SC7 I found, and it is also noisy and somewhat microphonic - I think the problem is in the amp, and not the tube, unfortunately. Will figure it out when I have a bit more time. .......
411: Vintage Asylum, RE: Microphonics ... (0.00)
Posted by maxhifi on 2009-11-08, 19:27:41 (199.126.250.124)
I tried a second used 6SC7 I found .......
412: Vintage Asylum, RE: 6SC7 should be easy to find... (0.00)
Posted by maxhifi on 2009-11-08, 17:55:28 (199.126.250.124)
I remembered a Hallicrafters receiver I have contains a 6SC7, and tried it in the Electrohome - no luck, same problem. I suspect bad old capacitors and/or a noisy resistor - will troubleshoot when I h .......
413: Vintage Asylum, RE: There are .7 mil styli available for your GE RPX ... (0.00)
Posted by maxhifi on 2009-11-08, 11:11:34 (199.126.250.124)
Great advice, thank you! So the issue with the GE playing stereo records is down to stylus size, and not anything else? I might have to order both a .7 mil stylus for the GE, and track down the Picker .......
414: Vintage Asylum, RE: GE RPX cartridge questions (0.00)
Posted by maxhifi on 2009-11-07, 18:31:42 (199.126.250.124)
Thank you, this is just what I was looking for. Stanton says it tracks at 3-7 grams, which is why it's my first choice. I am completely sure I could set it up for, say, 5 grams. The GE is a standard .......
415: Vintage Asylum, GE RPX cartridge questions (0.00)
Posted by maxhifi on 2009-11-07, 18:14:28 (199.126.250.124)
This might be pushing the limit of vintage a little bit - hope not. I have an old Electrohome console hi-fi I am refurbishing. It's an upper mid quality model from the early 50s, which is equipped wi .......
416: Tape Trail, RE: Not aware of any.... (0.00)
Posted by maxhifi on 2009-09-29, 14:38:13 (81.25.172.228)
London Drugs, in western canada still has a decent selection of blanks. I am not sure if they're out east or not. .......
417: Tweakers' Asylum, RE: Poor college student trying to upgrade to mid-fi (0.00)
Posted by maxhifi on 2009-07-24, 14:37:40 (81.25.172.228)
This sort of turntable is pretty well balanced as is. There is someone making aftermarket elliptical stili for this cartridge, (AT3600) but I think that the limiting factor here is by far the arm, so .......
418: High Efficiency Speaker Asylum, RE: did you try improving the xover caps to the tweeters? (0.00)
Posted by maxhifi on 2009-07-19, 16:07:33 (68.148.146.57)
Good point - I opened the crossovers to clean the L-pads, but never even looked at the caps. .......
419: High Efficiency Speaker Asylum, Not worth the effort (0.00)
Posted by maxhifi on 2009-07-16, 10:35:00 (81.25.172.228)
Since 1994 I have owned a pair of Triaxiom 212c in 7 cubic foot infinite baffle enclosures. I used them in my main system for about 5 years, while I was getting interested in tube amplifiers. Although .......
420: High Efficiency Speaker Asylum, RE: RCA Vintage Speakers - general questions (0.00)
Posted by maxhifi on 2008-12-05, 22:02:40 (209.29.53.12)
Yes, I have seen it - very informative and interesting website, and the archive page is a geat resource. I especially enjoyed reading the two "Sound Products" catalogues. .......
421: High Efficiency Speaker Asylum, RCA Vintage Speakers - general questions (0.00)
Posted by maxhifi on 2008-12-05, 21:26:36 (209.29.53.12)
I'd like to get a pair of RCA MI series speakers. I've had a pair of their old amps for years, and have always wanted some RCA speakers as well. I know the LC-1a is legendary, and some of the compres .......
422: Vinyl Asylum, Major Thanks! (0.00)
Posted by maxhifi on 2007-12-26, 19:34:17 (68.151.133.44)
Now, which one do I need? I assume this one http://www.kraudioproducts.com/SME/ProductDetail.aspx?CatID=71&ProductID=159 And, is it worthwhile to upgrade the bias weight holder to the one with the lit .......
423: Vinyl Asylum, SME 2012 rubber (0.00)
Posted by maxhifi on 2007-12-26, 10:59:16 (68.151.133.44)
Simple question - where can I get replacement rubber bushings for my 1967 vintage SME 3012 tonearm? (for the counterweight) .......
424: Tape Trail, Where to buy replacement heads for cassette deck? (0.00)
Posted by maxhifi on 2007-10-10, 14:46:23 (198.53.67.86)
Can someone please point me to a source of replacement mono heads, for cassette decks? Thanks in advance, Max .......
425: Tube DIY Asylum, RE: DIY 45 amp (0.00)
Posted by maxhifi on 2007-08-21, 13:15:10 (198.53.67.86)
Getting it working should be pretty easy, just choose a simple circuit. I built something similar unsing an EF37A driving a 2A3, and I am sure many others have too. Pay attention to layout - copy some .......
426: Tube DIY Asylum, RE: Tubes for transformer couple headphone amp? (0.00)
Posted by maxhifi on 2007-08-16, 14:29:47 (198.53.67.86)
6Y6G (cool looks, cheap price) 50L6/25L6 50EH5 6AQ5 (super cheap 7 pin 6V6 equivalent) 6L6GA in SE triode connection (looks cool) 6L6 (metal) in SE triode 6V6GT 2A3 with DC filament supply 6S4 6SN7GTB .......
427: Tube DIY Asylum, RE: preamp problem from non DIYer (0.00)
Posted by maxhifi on 2007-07-27, 10:22:27 (198.53.67.86)
hmm you said before it didn't hum, and now it does? Let's make sure it's really an internal problem first. 1. does the unit have a three prong power cord, and has anything changed with regards to pow .......
428: Tube DIY Asylum, RE: 2A3 (0.00)
Posted by maxhifi on 2007-07-26, 19:35:26 (68.151.133.44)
I think it's great - I built an SE 2A3 amplifier, but my speakers are not efficient enough to get the most from it. .......
429: SET Asylum, RE: It does matter (0.00)
Posted by maxhifi on 2007-07-17, 08:59:38 (198.53.67.86)
Theoretically push pull should do a better job of rejecting noise from the power supply, because there is some cancellation in the output stage. This is one reason why push pull amplifiers need smalle .......
430: Vintage Asylum, Re: Phase Linear 4000 - Repair advice needed! (0.00)
Posted by maxhifi on 2007-04-25, 00:12:29 (68.151.134.69)
Thanks for the response, and advice! I traced it to a bad 47uF cap on the one of the correlator boards. I took it apart today, cleaned everything, and put it all back together. From tonight's experien .......
431: Vintage Asylum, Phase Linear 4000 - Repair advice needed! (0.00)
Posted by maxhifi on 2007-04-24, 18:27:30 (68.151.134.69)
I had one of these come my way. It has a loud rushing noise when you turn on the "auto correlator" function - any ideas? This is for a friend .......
432: Tube DIY Asylum, Anecdotal advice (0.00)
Posted by maxhifi on 2007-04-19, 10:11:52 (198.53.67.86)
I used a pair of 19AU4's (I had an 18VCT power transformer from Radio Shack) The 19AU4's have lasted for years (I think I changed them once, but the originals I used were used tubes from old TVs) - a .......
433: Tubes Asylum, Re: Bass all gone (0.00)
Posted by maxhifi on 2007-04-18, 10:00:18 (198.53.67.86)
swap the channels - it might be a speaker problem if the tweeter is the only driver playing. .......
434: Tubes Asylum, Re: First Tube Failure (0.00)
Posted by maxhifi on 2007-04-16, 22:09:39 (68.151.134.69)
Based on my experience, 1500 hours seems like very little time Output tubes, if they are good quality, should be more like 3000 - 5000 hours, depending on how hot they are run. They should fail by los .......
435: Tube DIY Asylum, Re: When was the last time you cycled 300-450 Volts through your body? (0.00)
Posted by maxhifi on 2007-04-16, 09:50:39 (198.103.167.20)
About 1999 Touched the 450V B+ in my amplifier by accident, then threw my arm back, which caught my power supply's umbilical cord, knocking the amp on to the floor, where it landed on my toes, corner .......
436: SET Asylum, Re: Swap the output tubes; then the input tubes... (0.00)
Posted by maxhifi on 2007-04-03, 18:08:02 (198.53.67.86)
Did you try swapping the left and right signal cables feeding the amp? This has been a problem for me more than once. .......
437: Tube DIY Asylum, Local Loop feeback (0.00)
Posted by maxhifi on 2007-04-03, 12:55:12 (198.53.67.86)
"Yes. I tried local feedback as you describe for many years on and of - but always came back to no feedback with triodes. But if you (insist) on using pentode connection then it will be a big help - a .......
438: Tube DIY Asylum, Re: how do you plan to use them (0.00)
Posted by maxhifi on 2007-04-03, 10:38:22 (198.53.67.86)
In my (limited) experience, Sylvania tubes are better quality than RCA, will last longer, and are more likely to be on spec. .......
439: Tube DIY Asylum, Mullard 4-20 (NT) (0.00)
Posted by maxhifi on 2007-04-03, 10:36:26 (198.53.67.86)
. .......
440: Tube DIY Asylum, Re: Impulse Purchase (Piltron 1250 ohm PP 400W) output transformers (0.00)
Posted by maxhifi on 2007-04-01, 14:02:54 (198.53.67.86)
With such a large amplifier, I think it would be foolish to go with non standard tubes, as it's very likely you'll be changing them now and again, and it would be nice to have something easily availab .......
441: Speaker Asylum, Re: rca (tube driven era) 3 connector speaker contacts (0.00)
Posted by maxhifi on 2007-03-28, 12:03:02 (198.53.67.86)
It's the black round thing I am assuming. I think that's originally a battery connector, or if not, very similar to one. It will take some searching to dig those up - try antique electronic supply ::: .......
442: Tube DIY Asylum, Re: 6HR6 Work-Around? (0.00)
Posted by maxhifi on 2007-03-23, 09:01:27 (198.53.67.86)
Look online for other sources http://www.thetubestore.com/nos-6hr6.html etc Spend the $20 and then forget about it .......
443: Tube DIY Asylum, Re: Using A Tube With Two Diodes (0.00)
Posted by maxhifi on 2007-03-22, 01:01:56 (68.151.134.69)
What is it, a 12AV6? Ground the diodes .......
444: Tube DIY Asylum, Re: Source for inexpensive 1/4 inch plate/grid caps or?? (0.00)
Posted by maxhifi on 2007-03-20, 16:19:56 (68.151.134.69)
breadboarding? Lots of things will work for almost free A length of solid copper wire, AWG 18 - 14, wrapped into a spiral slightly smaller than the cap will fit very tight. You can solder your lead to .......
445: OTL Asylum, Re: help me concerning this amp (0.00)
Posted by maxhifi on 2007-03-18, 21:10:12 (68.151.134.69)
My advice, for what it's worth - don't bother. Build an SE EL84 amp, with a 12AX7 preamp tube. You can find transformers used from an old radio or console, or even buy them new. It will save time, and .......
446: Speaker Asylum, Re: hooking up speaker system (0.00)
Posted by maxhifi on 2007-03-17, 19:04:21 (68.151.134.69)
why do you need 3 speakers?? Generally speaking, speakers are used as stereo pairs, unless we are talking home theatre. If you insist on having all 3 connected, I'd connect the KLH pair to the "speake .......
447: Tape Trail, Sony TC-RX420 (0.00)
Posted by maxhifi on 2007-02-19, 10:04:38 (198.103.167.20)
After many years of good service, my Teac A-100 lost the ability to rewind and fast forward, and the play button became loose. I checked out the price of new belts, and it would be about $20 US plus s .......
448: High Efficiency Speaker Asylum, Corner Placement Room Gain (0.00)
Posted by maxhifi on 2006-08-14, 09:23:29 (198.103.167.20)
I have read, and subjectively experienced that speakers placed in the corner will have enhanced bass response over speakers which are not placed in the corner. Up until now, I have always kept my spea .......
449: Speaker Asylum, Re: non EIA speaker codes (0.00)
Posted by maxhifi on 2006-08-13, 20:07:02 (68.151.134.69)
These sound like Canadian codes to me, but I don't know enough to do anything more than guess .......
450: High Efficiency Speaker Asylum, Fostex 400HT (0.00)
Posted by maxhifi on 2006-06-09, 13:09:32 (198.103.167.20)
Has anyone tried this tweeter, as available from madisound for home hi-fi applications? If so, what did you think of it? thanks Max .......
451: Tube DIY Asylum, Re: Best sounding driver stage for SE 2A3 amp? (0.00)
Posted by maxhifi on 2006-05-24, 16:36:57 (68.151.134.69)
I'm not qualified to give you a real answer to your question, not having tried all of those topologies, but my amplifier using an EF37A driving a 2A3 sounds very good in most ways, within its limits. .......
452: Tube DIY Asylum, Re: Can I use a transformer from a push-pull 6v6 amp for 300B SET? (0.00)
Posted by maxhifi on 2006-05-23, 14:27:52 (198.103.167.20)
I just completed a project using a power transformer from a push-pull 6V6 amplifier for a stereo 2A3 amplifier, so it can be done... I wouldn't use the output transformer though. .......
453: Tube DIY Asylum, Re: 50c5 tubes (0.00)
Posted by maxhifi on 2006-05-22, 21:57:41 (68.151.134.69)
I had a portable record player, with one of those really cheap Garrard changers, and an even cheaper line powered stereo amplifier using two 50EH5's (the high transconductance cousin of the 50C5). Whe .......
454: Tube DIY Asylum, Re: 50c5 tubes (0.00)
Posted by maxhifi on 2006-05-22, 15:27:07 (68.151.134.69)
www.tubesandmore.com has them - all other tube dealers which cater to the antique radio crowd should have them too. - they're the power output tube for just about every low priced AM radio made betwee .......
455: Tube DIY Asylum, Speakers (0.00)
Posted by maxhifi on 2006-05-19, 20:17:50 (68.151.134.69)
"My drivers are made by an Australian company called Rola (or later Plessey-Rola). They are 8" (I think the type number on them is C8P from memory). They are not coaxially mounted speakers like your G .......
456: Tube DIY Asylum, Re: It's 2A3 for me (0.00)
Posted by maxhifi on 2006-05-19, 20:07:29 (68.151.134.69)
My coupling cap is .22uF now - I think you might be right, and I'm considering building a tube phono stage anyway, so I may as well leave it to that point before I think about warp filters seriously. .......
457: Tube DIY Asylum, Re: It's 2A3 for me (0.00)
Posted by maxhifi on 2006-05-19, 20:02:32 (68.151.134.69)
My amplifier is EF37A -> 2A3 similar to WE91 topology Rectifier is a 6CA4 for both stereo channels it's playing right now... sounds great .......
458: Tube DIY Asylum, RIAA Preamp Options (0.00)
Posted by maxhifi on 2006-05-19, 10:39:19 (198.103.167.20)
I've got my 2A3 amplifier up and running beautifully.... now I'm thinking about tube based RIAA amplifiers, to match with my MM cartridge. I'm currently using the phono section of a rebuilt McIntosh C .......
459: Tube DIY Asylum, Re: It's 2A3 for me (0.00)
Posted by maxhifi on 2006-05-19, 08:42:28 (198.103.167.20)
I've listened to the amplifier quite a lot more now, and I have a few more comments about it 1. I think it needs some kind of a steep but very low frequency high pass filter, because record warps can .......
460: Tube DIY Asylum, Re: Amperage Rating Of Wires (0.00)
Posted by maxhifi on 2006-05-18, 17:00:17 (68.151.134.69)
After I posted it, I checked it again, and it does look like the power transmission column is a bit low, and the chassis column is a bit high for my liking - compare 14AWG at 5.9A to the 15A it gets w .......
461: Tube DIY Asylum, Re: Amperage Rating Of Wires (0.00)
Posted by maxhifi on 2006-05-18, 14:11:23 (198.103.167.20)
This should help .......
462: SET Asylum, Re: switch for 8 or 16 ohm impedance form output transformer (0.00)
Posted by maxhifi on 2006-05-18, 11:32:27 (68.151.134.69)
Switching it live shouldn't present any problems to the amplifier, tubes are pretty tough - but why would you want to? Why not just install 3 terminals instead of two, like on a normal amplifier? The .......
463: Tube DIY Asylum, Re: Thanks guys. ???One more question, please??? (0.00)
Posted by maxhifi on 2006-05-18, 00:28:21 (68.151.134.69)
yes... don't rely on the screw threads as the only means of contact, get it to bare metal under whatever you're screwing down .......
464: Tube DIY Asylum, dremel with the little grinding wheel (nt) (0.00)
Posted by maxhifi on 2006-05-18, 00:26:58 (68.151.134.69)
. .......
465: Tube DIY Asylum, It's 2A3 for me (0.00)
Posted by maxhifi on 2006-05-17, 20:47:10 (68.151.134.69)
I just finished my 2A3 amplifier, which I was posting about on here about a month ago. I hooked everything up as per my schematic, and was rewarded with a dead silent background, and a perfectly opera .......
466: High Efficiency Speaker Asylum, Re: DIN 45575 IEC BAFFLE - what is it? (0.00)
Posted by maxhifi on 2006-05-17, 14:51:35 (68.151.134.69)
This is exactly what I was looking for, thanks very much! .......
467: High Efficiency Speaker Asylum, DIN 45575 IEC BAFFLE - what is it? (0.00)
Posted by maxhifi on 2006-05-16, 10:00:13 (198.103.167.20)
I often see speakers tested on the baffle listed in the subject line - I assume it's some sort of standard testing baffle, but can does anyone have the specs for what it actually is? thank you ::: TOP .......
468: Tube DIY Asylum, Re: Suggest One Book (0.00)
Posted by maxhifi on 2006-05-08, 09:12:57 (198.103.167.20)
Go to your closest university, and look in their technical library... if it's been around for any length of time, they'll have hundreds of books and periodicals on tube theory, circuit design, etc. It .......
469: Tubes Asylum, a few things (0.00)
Posted by maxhifi on 2006-05-06, 22:54:59 (68.151.134.69)
- system dosen't go as loud as it used to - rushing, or popping noise occurs, maybe intermitantly - tubes have been used for many thousands of hours - lightly tapping the tube when it's on (say with t .......
470: OTL Asylum, Re: A predicament.... (0.00)
Posted by maxhifi on 2006-05-06, 11:14:02 (68.151.134.69)
This one is easy.... finish the horn first, then move on... otherwise you'll end up like me and have a bunch of half done projects laying around :) .......
471: High Efficiency Speaker Asylum, SPL at chair (0.00)
Posted by maxhifi on 2006-05-01, 09:05:06 (198.103.167.20)
Ok, let's see 10 log (0.2/1) = -6dB So, if I have a 2W amplifier, I'm looking at my speaker's sensitivity minus 6dB at one meter, as my maximum average listening level. Now, how do I figure out what t .......
472: High Efficiency Speaker Asylum, Re: How efficient for SE 2A3? (0.00)
Posted by maxhifi on 2006-04-27, 23:28:19 (68.151.134.69)
The Tannoys are 6 ohms... worth a shot anyway though nothing to lose .......
473: High Efficiency Speaker Asylum, Re: How efficient for SE 2A3? (0.00)
Posted by maxhifi on 2006-04-27, 08:45:39 (198.103.167.20)
hmm 91 is about where my Tannoys are. They're much better speakers than anything else I can afford at the moment specifically for the 2A3's, so I'll give them a try! .......
474: Tube DIY Asylum, SS Rectifiers, etc (0.00)
Posted by maxhifi on 2006-04-24, 09:50:14 (198.103.167.20)
I'll have access to the transformer on wednesday, at which time I'll measure it, etc. It's got to be very low impedance though, considering it's rated to deliver over 4 amps at 240V, and no, it's not .......
475: Tube DIY Asylum, Now what's the fun in that idea??? Here's another one... (0.00)
Posted by maxhifi on 2006-04-24, 00:47:10 (68.151.134.69)
I have no interest in buying a "T" amp.... I've been "on" tubes for the past 13 or so years, with no plans to go back. I guess I just didn't consider that a low impedance power supply could possibly b .......
476: Tube DIY Asylum, Re: Just thought of this point - I think I'd better build this thing first (0.00)
Posted by maxhifi on 2006-04-23, 20:48:40 (68.151.134.69)
I agree, it would be a good idea to do that (in fact I did do it once, with a different transformer and big bank of light bulbs), but my resources are fairly limited right now, so I'm trying to keep c .......
477: Tube DIY Asylum, Re: Somebody please check his resistor values !!! Dissipation wise !! (0.00)
Posted by maxhifi on 2006-04-23, 20:27:48 (68.151.134.69)
44 Volts, at 110mA for both tubes is 4.84 watts, which is less than half the rating, so should be safe ummm... yes.... white coffin is bad you say... you nailed it though, it's exactly what I ordered. .......
478: Tube DIY Asylum, Here, you go, sir! (0.00)
Posted by maxhifi on 2006-04-23, 20:12:13 (68.151.134.69)
Before I say anything else, I have to say this forum is wonderful, I honestly can't believe how everyone is bending over backwards to help me with my one little project! what a great community of enth .......
479: Tube DIY Asylum, Here's my iron (0.00)
Posted by maxhifi on 2006-04-23, 18:40:11 (68.151.134.69)
In order of appearance... the power transformer, the choke, and and one of the two output transformers the dead UX-245 (may you RIP) is for size comparison .......
480: Tube DIY Asylum, Re: Eliminate 150 Ohms of Series Resistance (0.00)
Posted by maxhifi on 2006-04-23, 18:28:45 (68.151.134.69)
"We could have a supply with a choke in the first position, but if the henry value of that choke (determined by the working voltage and the current draw) is too small, the supply will act as a capacit .......
481: Tube DIY Asylum, Just thought of this point - I think I'd better build this thing first (0.00)
Posted by maxhifi on 2006-04-23, 18:25:26 (68.151.134.69)
I really have no idea how good the voltage regulation of my power transformer is. It came out of a 1951 RCA console hifi which had an AM tuner and a push pull 6V6 amplifier. I designed the power suppl .......
482: Tube DIY Asylum, That's about what I though too - thanks. (nt) (0.00)
Posted by maxhifi on 2006-04-23, 18:12:37 (68.151.134.69)
- .......
483: Tube DIY Asylum, Re: Eliminate 150 Ohms of Series Resistance (0.00)
Posted by maxhifi on 2006-04-23, 16:18:46 (68.151.134.69)
Okay, makes sense. But won't the 100uF capacitor average this out, and lower the impedance of the supply for those quick variations? It's not as though the 150ohms is directly between the last capacit .......
484: Tube DIY Asylum, Re: Eliminating the 150 Ohms of Series Resistance (0.00)
Posted by maxhifi on 2006-04-23, 16:02:32 (68.151.134.69)
it measures 44.5 ohms, and it's wound on a 1" stack of E-I laminations, which are 2.5" by 3". The laminations are oriented such that their is a gap so it can pass DC. I don't know the actual value in .......
485: Tube DIY Asylum, Re: Eliminating the 150 Ohms of Series Resistance (0.00)
Posted by maxhifi on 2006-04-23, 13:35:33 (68.151.134.69)
I was playing with this idea myself, but I found the value of the cap is quite critical, and it seriously harms the ripple voltage figure, like by a factor of 5 or 10 - how much ripple is OK for a SET .......
486: Tube DIY Asylum, Re: first time posting an image - try this one (0.00)
Posted by maxhifi on 2006-04-23, 11:17:31 (68.151.134.69)
As I said, I did it strictly to be cheap, and to get the amplifier working soon... I honestly don't like the idea of running the filaments in series, but I will add a little bit of resistance if they .......
487: Tube DIY Asylum, Re: first time posting an image - try this one (0.00)
Posted by maxhifi on 2006-04-23, 11:07:13 (68.151.134.69)
I'm going to be doing all the wiring on terminal strips, so this kind of mod will be dead easy to do.... I'll keep this in mind for the first round of upgrades! .......
488: Tube DIY Asylum, Re: good for you! (0.00)
Posted by maxhifi on 2006-04-23, 11:05:42 (68.151.134.69)
I can hardly take credit for the idea, I have seen it done on several schematics online, as well as on several cheap amplifiers which use more modern indirectly heated tubes. I figure that with such a .......
489: Tube DIY Asylum, Re: Eliminate 150 Ohms of Series Resistance (0.00)
Posted by maxhifi on 2006-04-23, 10:56:14 (68.151.134.69)
I put them there for two reasons 1. not exceed the peak current rating of the 6CA4 2. get the voltage down so the 2A3 is operating at the right point (250V) - It looked more linear this way as opposed .......
490: Tube DIY Asylum, Re: Have you thought of using an innerstage transformer (0.00)
Posted by maxhifi on 2006-04-22, 18:47:00 (68.151.134.69)
This is very good to know - I know someone who has a Citation II which he built as a kit in the early 1960s... it was the first tube amplifier I ever saw, and I plan on making an offer one of these ye .......
491: Tube DIY Asylum, Re: first time posting an image - try this one (0.00)
Posted by maxhifi on 2006-04-22, 18:36:28 (68.151.134.69)
I must have forgot to put that on the schematic... the reference to ground should be a 150k resistor which for some reason I didn't draw. Thanks for pointing that out! The bias supply is in an effort .......
492: Tube DIY Asylum, Re: Have you thought of using an innerstage transformer (0.00)
Posted by maxhifi on 2006-04-22, 16:36:11 (68.151.134.69)
Took a look at your profile Wow - you have a Citation II, AND a pair of MC60's??? Those have both been on the dream amplifier list for years... which one do you like better? Or is it a case of both ha .......
493: Tube DIY Asylum, Re: Have you thought of using an innerstage transformer (0.00)
Posted by maxhifi on 2006-04-22, 16:01:41 (68.151.134.69)
I will have room on the chassis for them! I am going to build it as shown, since I already ordered the parts, but that's definitly a future upgrade idea! I sure don't like how those square waves look, .......
494: Tube DIY Asylum, first time posting an image - try this one (0.00)
Posted by maxhifi on 2006-04-22, 14:47:42 (68.151.134.69)
- .......
495: Tube DIY Asylum, final 2A3 amplifier schematic - any comments? (0.00)
Posted by maxhifi on 2006-04-22, 14:43:18 (68.151.134.69)
Thank you to everyone who offered me advice on this project so far. Here is the schematic of the amplifier I ordered parts for, and will build. I don't have a scanner, so I used my digital camera, it .......
496: High Efficiency Speaker Asylum, Re: I cannot imagine using 2A3s SE with 96db efficient speakers (0.00)
Posted by maxhifi on 2006-04-21, 14:33:58 (198.103.167.20)
I better give some more background so you can see what angle I'm coming from with this question. The reason I'm building the 2A3 amps, is I ordered a really nice pair of output transformers about 3 ye .......
497: Tube DIY Asylum, Re: Which amp would you build? (0.00)
Posted by maxhifi on 2006-04-21, 12:07:34 (198.103.167.20)
like the other guys say, buy an old dynaco, or a pair of heathkits, or etc and replace the resistors and capacitors .......
498: Tube DIY Asylum, Re: The williamson mullard??? (0.00)
Posted by maxhifi on 2006-04-21, 11:50:15 (198.103.167.20)
The williamson was set up to drive triode connected output tubes, with a nice clean 6SN7 driving them. The Mullard on the other hand is using a comparitively anemic 12AX7. Some Eico variations on the .......
499: Tube DIY Asylum, Re: Looking for preamp and EL34 amp schematics (0.00)
Posted by maxhifi on 2006-04-21, 11:44:57 (198.103.167.20)
www.triodeel.com has a nice replacement driver board for the ST-70, you will find that the 7199's originally called for are expesive and rare. It would be easy to buy that board, and some transformers .......
500: High Efficiency Speaker Asylum, Re: How efficient for SE 2A3? (0.00)
Posted by maxhifi on 2006-04-21, 08:56:24 (198.103.167.20)
Looks like the magic number is ~96dB. Thanks everyone for your responses, I ordered all the parts for my amplifier last night, and in a few weeks I'll be ready to start fooling around with speaker ide .......
Found total of 500 records, Query: , Author: maxhifi in All Forums, Time: 1 sec.