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1: Tube DIY Asylum, RE: Of course there's a difference (0.00)
Posted by Stuben on 2022-02-26, 09:38:51 (50.5.138.226)
TK, We do have a problem when we provide resources to watch the little guy but not our Oligarchs $$ who have bought OUR government. Government is not the problem, the folks who purchase our Government .......
2: Tube DIY Asylum, RE: Looking for Other Low Wattage SE OPT Options (0.00)
Posted by Stuben on 2022-02-01, 15:57:18 (50.5.138.226)
Lundahl LL1663 5K primary 50 mA Stuben .......
3: Digital Drive, RE: MQA damage (0.00)
Posted by Stuben on 2021-11-28, 12:00:13 (50.5.138.226)
I stream Tidal and have MQA compliant DACs. I hear a great increase in overall performance with MQA content. I really don't care about claims from any camp for or against. My ears tell my what I need. .......
4: Tube DIY Asylum, RE: amp build (0.00)
Posted by Stuben on 2021-11-17, 12:22:11 (50.5.138.226)
While you are fiddling with feedback, try output feedback by tying you OPT cathodes to ground through the secondary of the OPT transformer in addition to your cathode load. I don't like the sound of U .......
5: SET Asylum, RE: Budget speakers to pair with SET amp (0.00)
Posted by Stuben on 2021-10-13, 13:32:07 (174.46.140.130)
I built a pair of Madisound Back loaded cabinets with FE206ne drivers and a couple of old super tweeters I had in stock. Crossover only on the tweeters. $750. Getting ready to replace the inexpensive .......
6: Tube DIY Asylum, RE: CCS question about 6SL7 Cathode Resistor (0.00)
Posted by Stuben on 2021-03-20, 11:17:59 (208.102.196.236)
I used a K&K coscode CCS to load 6sl7 a few years ago, worked OK. The 6SN7 is a much better fit if you can get by with the Mu. I tend to go with the highest transconductance driver that will provide e .......
7: Tube DIY Asylum, Re: 5687 ? (0.00)
Posted by Stuben on 2021-03-19, 11:05:10 (208.102.196.236)
Hey TK, I'm driving (2) channels of PP ITs in my dual mono PP amp. Using a single 6n30p-dr. I've never experienced any audible cross talk. Stuben .......
8: Tube DIY Asylum, RE: SE 6V6 E-Linear : found my schematic ... (0.00)
Posted by Stuben on 2020-12-30, 12:31:07 (208.102.196.236)
Our Guy at Glassware shared something like this with us a while back. As stated by our gurus, takes some artistic patients... Stuben .......
9: Tube DIY Asylum, RE: Another 5842 question, grid and cathode (0.00)
Posted by Stuben on 2020-11-11, 14:43:25 (208.102.196.236)
Good point, I've too busy listening. I'll put a scope on see what I see. Stuben .......
10: Tube DIY Asylum, RE: Another 5842 question, grid and cathode (0.00)
Posted by Stuben on 2020-11-10, 12:58:45 (208.102.196.236)
Funny, just checked mine from a build 12 years or so ago, 270 ohms on all (4) with a ferrite bead. It surprised me. I don't remember why I made the decision but I've never had any "Audible" issues...I .......
11: SET Asylum, RE: Last night I measured My lowest Hum level ... (0.00)
Posted by Stuben on 2020-11-09, 16:56:26 (208.102.196.236)
Lipo Batteries? :) Good job. How many turns are on your pots? Stuben .......
12: SET Asylum, RE: Looking for SET amp for my Altec speakers (0.00)
Posted by Stuben on 2020-10-19, 18:22:48 (208.102.196.236)
The strapped pentodes will do a decent job at 2 watts with the efficiency you're working with. The 2a3 approach will let more magic out using a comparably thought out design and build. I've implemente .......
13: Tube DIY Asylum, RE: What makes a high quality plate choke? .... Better yet .... (0.00)
Posted by Stuben on 2020-10-09, 13:34:32 (66.42.221.248)
I'm running SE K88 with cathode feedback across the Output secondary. The input is 6sn7 cascade with second stage CF - RL coupled. Haven't made any real measurements but the sound is very palatable. H .......
14: Tube DIY Asylum, RE: Amp Issue (0.00)
Posted by Stuben on 2020-08-15, 10:10:26 (66.42.221.248)
Checked the connections and one channel is open to grid to ground on the pot. Nice sounding AN pot. Looks like the pot connection has failed. I was able to wiggle it around and get some continuity to .......
15: Tube DIY Asylum, RE: Amp Issue (0.00)
Posted by Stuben on 2020-08-15, 05:54:27 (66.42.221.248)
Thanks Paul, Yea after the post, I thought some more about heat. I have had heat issues with position I placed the amp, in furniture with little head space. I've also had funky heat related issues in .......
16: Tube DIY Asylum, Amp Issue (0.00)
Posted by Stuben on 2020-08-14, 14:05:37 (66.42.221.248)
Guys, One of my builds has developed an issue. After some time in service, one of the channels goes 100% with the volume at 0%.The other channel sounds slightly distorted. I do do have CCS feeding th .......
17: Tube DIY Asylum, RE: Sorry Folks (0.00)
Posted by Stuben on 2020-07-18, 12:12:13 (208.102.169.8)
I believe this is the DIY forum. Total agree never though I down played measurement. Unless a technician is provided with every product, You buy or build for your listening experience which includes .......
18: Tube DIY Asylum, RE: Bad socket then? (0.00)
Posted by Stuben on 2020-07-18, 11:59:45 (208.102.169.8)
Lots of ways to make an oscillator. I would be interested in seeing a scheme of your voltage amplifier. Stuben .......
19: Tube DIY Asylum, RE: Sorry Folks (0.00)
Posted by Stuben on 2020-07-12, 11:08:03 (4.30.82.186)
Measurement gets you to the ball park. The Game is the synergy of components required from source to the ear. You can't get the magic out with individual well measured components alone. Stuben ::: T .......
20: Tubes Asylum, RE: Opinions??? (0.00)
Posted by Stuben on 2020-05-15, 12:49:34 (66.42.220.231)
If it were point to point wiring would be worth the effort and $$. I have used a Valab NOS DAC for years. Decent product. Assuming a certain level of quality, chassis, assumed decent iron is worth th .......
21: General Asylum, RE: it's amazing (0.00)
Posted by Stuben on 2020-05-01, 08:55:06 (66.42.220.231)
bean, I started building in 2002 I'm now 57. I'm also experiencing the eye issues. I've have (4) Rod Coleman Reg boards on my bench. I can't get up the gumption to start soldering:( The point to point .......
22: General Asylum, RE: Who is better? The Beatles or The Rolling Stones? (0.00)
Posted by Stuben on 2020-04-26, 07:14:57 (66.42.220.231)
Yes The WHO is better. In my mind it's a bad comparison. The Beatles were a boy band trying to be a Blues / Rockabilly band and the Stones were a Blues band trying to be a boy band. The Beatles eventu .......
23: Tube DIY Asylum, RE: Need help selecting a 5.0volt D.C. module for 300B filament , (0.00)
Posted by Stuben on 2020-04-10, 12:10:27 (66.42.220.231)
Will, I remember seeing this in a post a few weeks ago. http://www.intactaudio.com/fil.html Could be a real estate saver Stuben .......
24: Tube DIY Asylum, RE: Need help selecting a 5.0volt D.C. module for 300B filament , (0.00)
Posted by Stuben on 2020-04-10, 11:33:40 (66.42.220.231)
I guess I need to mention a CRC filter prior to the regulator. (I know you know that) AC heating with 5.0 volts would yield some hum but it would require the least amount of foot print. I'm working o .......
25: Tube DIY Asylum, RE: Need help selecting a 5.0volt D.C. module for 300B filament , (0.00)
Posted by Stuben on 2020-04-10, 10:38:08 (66.42.220.231)
Hey Will, You can use a Rod Coleman regulator which would mean you could probably avoid a big choke. I have (4) of on my bench. The only problem is as we age, those little boards get harder and harder .......
26: General Asylum, RE: Certainly better things the government could do with the money... (0.00)
Posted by Stuben on 2020-04-04, 08:08:43 (66.42.220.231)
Agreed, we can't restart the economy until we have decent facts on the ground. The folks in real trouble show get help first. Facts on the ground will help decide that also. Knowing where our friend h .......
27: General Asylum, RE: The American Enterprise institute (0.00)
Posted by Stuben on 2020-03-29, 08:15:24 (66.42.220.231)
Thanks...Yea, The Middle class income doesn't quiet buy what it used to. Coming from a working class family in the 60s and 70s it is obvious we are running with the goal posts. Opportunity per dollar .......
28: Tubes Asylum, RE: Work from home question.... (0.00)
Posted by Stuben on 2020-03-27, 11:28:28 (66.42.220.231)
Unless you're willing to measure and modify in response to results, please just enjoy the music. If you purchased an amp where you can't afford to replace the valves, the concern lies elsewhere...:) I .......
29: Inmate Central, RE: State of Confusion--not just an old Kinks song anymore... (0.00)
Posted by Stuben on 2020-03-13, 08:47:01 (69.61.128.82)
I'm in the Cincinnati area, just read that Ohio health care folks "predict" that there are 100,000 cases of this stuff in Ohio... I agree, our leadership can't win on this one. You shut things down, y .......
30: General Asylum, RE: The difference in the flu and the corona virus.. (0.00)
Posted by Stuben on 2020-03-06, 05:06:07 (69.61.128.82)
I do find it interesting that in a day when "States Rights" are king screw the over reach of the Fed, we expect some sort of guidance or help when shit gets weird but thumb our noses when the Fed trie .......
31: General Asylum, RE: How Would You Handle a Package from China? (0.00)
Posted by Stuben on 2020-03-06, 04:59:39 (69.61.128.82)
If we don't contract it this season, it will be waiting for us next season. I guess it is matter of having some control over the inevitable. Stuben .......
32: Vinyl Asylum, RE: Amazon Prime video has a nice documentary about ZZ Top. (0.00)
Posted by Stuben on 2020-03-05, 09:16:52 (69.61.128.82)
Good documentary. personally, they lost me after Degualo when they started the whole MTV thing...Billy Gibbons solo stuff is great. Stuben .......
33: Tube DIY Asylum, RE: Note the interstage is in 1:2.25 (0.00)
Posted by Stuben on 2020-03-04, 09:51:19 (69.61.128.82)
After some trial and error, I connected my 1660s with all primaries in series for max H. I never looked back. I was NOT driving a big triode though. Stuben .......
34: Tube DIY Asylum, RE: Voyager 300B SE with EF86 / 6V6 (0.00)
Posted by Stuben on 2020-03-04, 09:15:44 (69.61.128.82)
I'm with TK, the EF86 is far superior even as a Pentode as far as I'm concerned. Stuben .......
35: Tube DIY Asylum, RE: SE IT, Flux reserved for AC and DC (0.00)
Posted by Stuben on 2020-02-29, 07:33:45 (66.42.220.231)
Eric, That has been my experience but it really depends on the severity of the saturation. If you can you put them in the circuit for a try without a huge amount of trouble, you should give it a try a .......
36: Tube DIY Asylum, RE: SE IT, Flux reserved for AC and DC (0.00)
Posted by Stuben on 2020-02-28, 08:43:48 (69.61.128.82)
Eric, It will work. Depending on how much you actually saturate the core, you'll lose on the low and high end. Throw a wet blanket over your speakers if you want a sample. (a worse case example) :) St .......
37: Tube DIY Asylum, RE: Wire gauges (0.00)
Posted by Stuben on 2020-02-28, 06:46:00 (69.61.128.82)
Hey Ray, I typically use 18-22 gauge wire (under the chassis) across the board for amp projects. For filaments, the use of a shielded pair cable helps. Only ground the shield on one side. These cha .......
38: Tube DIY Asylum, RE: Are you convinced what this guy said about 845 (0.00)
Posted by Stuben on 2020-02-25, 12:05:39 (69.61.128.82)
I have only built a parafeed line stage. Just wondering about the low end limitation associated with a power amp of this topology.. need to do some digging. I'm sure the Cap is a huge factor. Stuben .......
39: Tube DIY Asylum, RE: Are you convinced what this guy said about 845 (0.00)
Posted by Stuben on 2020-02-25, 12:00:45 (69.61.128.82)
Tre, Funny I was just re-reading an article written by Claus Byrith on a SEP build. From article below: Unfortunately an air gap reduces primary inductance and decreases coupling between primary and s .......
40: Tube DIY Asylum, RE: Are you convinced what this guy said about 845 (0.00)
Posted by Stuben on 2020-02-25, 10:44:19 (69.61.128.82)
I'd tell this individual to keep trying. Anyone who has spent time building audio systems knows Technical tenacity is your best attribute. Again, the system as a whole ... BTW, what would be the defin .......
41: Tube DIY Asylum, RE: High input or output impedance (0.00)
Posted by Stuben on 2020-02-18, 07:16:42 (69.61.128.82)
I found this link in my old file of links....must be getting old and forgetful...not really a simple answer...looks like several. https://www.electronicdesign.com/technologies/communications/article/ .......
42: High Efficiency Speaker Asylum, RE: spend some time with a 1970s pair of Heresys (0.00)
Posted by Stuben on 2020-02-18, 06:54:40 (69.61.128.82)
Most full range driver have the propensity for what I call "2k shout" where the their curves spike providing an unpleasant listen fatigue. You'll know it when you hear it...I'm sure you can get a simi .......
43: Tube DIY Asylum, RE: High input or output impedance (0.00)
Posted by Stuben on 2020-02-18, 06:36:05 (69.61.128.82)
Eli, What would be a good "Rule of thumb" for impedance matching between let's say a Line Stage and a Power amp? I have had interesting results using different output and input impedance between stage .......
44: Computer Audio Asylum, RE: Unless using streaming services, why is dedicated audio machine connected to Internet in the first place? (0.00)
Posted by Stuben on 2020-02-14, 08:27:18 (69.61.128.82)
That's a fair question. If you don't need to be connected to Ethernet media, don't ...the adapter just puts an unnecessary burden on the processor. Stuben .......
45: Speaker Asylum, RE: Shouting (0.00)
Posted by Stuben on 2020-02-14, 06:26:49 (69.61.128.82)
All of the full range drivers are capable of the 2k shout. The system as a whole needs to be assessed. Your room, amplifier dampening, your baffle correction, Your enclosure. I've been working with Fo .......
46: Tube DIY Asylum, RE: Voyager 300B SE with EF86 / 6V6 (0.00)
Posted by Stuben on 2020-02-11, 10:07:10 (69.61.128.82)
I use a 417a into a LL1692A IT works well. Just need to deal with 4 hot grids... Stuben .......
47: Tube DIY Asylum, RE: Tranny coupling versus cap coupling (0.00)
Posted by Stuben on 2020-02-04, 05:30:49 (69.61.128.82)
You can get good results with both. I find IT coupling to be little more challenging as far as establishing the optimum H and primary current when loading the preamp section. When you get it right, th .......
48: Tube DIY Asylum, RE: You might want to make sure your amp was designed for ECC99 (0.00)
Posted by Stuben on 2020-01-28, 14:14:03 (69.61.128.82)
I agree with Chip. The values on your RC coupling look off. Run your calc and reassess. CCS loading the first section of the ECC99 will likely provide some interesting results in light you're tweaking .......
49: Tube DIY Asylum, RE: Reduce 3rd order distortion, CCS or carhode Degeneration? (0.00)
Posted by Stuben on 2020-01-28, 09:32:21 (69.61.128.82)
Hey Eric, If you have the room under the chassis, plate loading with a CCS (in my experience) will provide better distortion levels and will open up the ability of the voltage amp to drive with less d .......
50: Tube DIY Asylum, RE: Another Mouser story (0.00)
Posted by Stuben on 2020-01-24, 10:39:05 (66.42.220.231)
I picked mine up at Part Express. Stuben .......
51: SET Asylum, RE: Need Replacement Tamura Power Transformer Sun Audio (0.00)
Posted by Stuben on 2020-01-23, 07:01:48 (165.225.0.73)
Hey Mike, Have you figured out what happened as far as cause? You need to check your coupling caps and any other component that will facilitate a high current draw on failure before you replace the po .......
52: High Efficiency Speaker Asylum, RE: New Fostex FE- NV Series (0.00)
Posted by Stuben on 2020-01-17, 07:38:11 (69.61.128.82)
I've been working with the FE206ne, and fe166ne for few years. Like everything else in Audio, it's all about the design of the system. I find the Fostex offerings a very good value considering their p .......
53: Tube DIY Asylum, RE: Why cathode bais is normally preferred for 300B SE (0.00)
Posted by Stuben on 2020-01-16, 06:05:28 (69.61.128.82)
Fixed bias requires more design and real estate. In light that many folks prefer the sound of Auto Bias, the ROI is not necessarily there. You can bypass with a better quality cap or don't bypass. I'v .......
54: Tube DIY Asylum, RE: Not soldering - Waygo connectors (0.00)
Posted by Stuben on 2020-01-16, 05:30:57 (69.61.128.82)
Interesting..I specified Wago terminals in a Paper Mill control system back in 89...The installing electricians hated me...they ended filing down screw drivers to accommodate. They make decent connect .......
55: Tube DIY Asylum, RE: SMPS DC heater supply : part 2 (0.00)
Posted by Stuben on 2020-01-03, 04:19:18 (69.61.128.82)
For a IDHT, your wave form will probably be transparent enough. For a DHT, a minute sine wave sounds better than any form on angles. Stuben .......
56: SET Asylum, RE: Coupling Caps for a 300B SET (0.00)
Posted by Stuben on 2020-01-03, 04:14:38 (69.61.128.82)
For bang for the buck, Russian PIO have been my go to for a few years. The price is going up. Stuben .......
57: Tube DIY Asylum, RE: You can do that (0.00)
Posted by Stuben on 2019-12-18, 04:34:22 (69.61.128.82)
Hi Eric, I think someone has already mentioned this but, you are close enough to the 10% spec. If the lower voltage really bothers you...you can regroup and connect the sections in parallel provided y .......
58: Tube DIY Asylum, RE: Need advice in design, ECC99 What is your experience (0.00)
Posted by Stuben on 2019-12-02, 09:15:05 (66.42.231.242)
I agree less is better. I have avoided direct coupling mostly because I have never heard the sonic results. I'm probably under estimating the ROI. Stuben .......
59: Tube DIY Asylum, RE: Need advice in design, ECC99 What is your experience (0.00)
Posted by Stuben on 2019-12-01, 11:53:50 (50.5.140.254)
Eric, Brave man. I started building doing the same thing only the rigs didn't cost that much... A couple of things: 1. The miller cap of those big plates has be to considered. Which is the reason fo .......
60: SET Asylum, RE: Need Help for Emission Labs 300B Mesh (0.00)
Posted by Stuben on 2019-11-29, 11:30:00 (50.5.140.254)
Interesting scheme. My only comment is there is a hefty amount of DCR on the B+. Might consider using minimal H and DCR and still accommodate critical inductance and then simulate for sanity. Stuben : .......
61: Tube DIY Asylum, RE: anyone try this low current CCS board ... (0.00)
Posted by Stuben on 2019-11-26, 06:27:20 (66.42.231.242)
I've been working with Kevin for about 20 years. Lundahl is my goto for signal transformers. I've applied his CCS kits many times. He is an outstanding resource, a straight shooter and a nice guy. Stu .......
62: Tube DIY Asylum, RE: Need advice, low plate voltage on 5687 (0.00)
Posted by Stuben on 2019-11-25, 07:39:15 (66.42.231.242)
Eric, You're gong to be outside the tubes operating range. The distortion and linearity will be buggered. You can give it try. You might have better luck at that voltage with the 6922 family. BTW, TH .......
63: SET Asylum, RE: Webster output transformers (0.00)
Posted by Stuben on 2019-11-22, 11:45:07 (50.5.140.254)
Hey wclarson12, If gapped, it's probably SE. So yes the max usable current on the primaries is fixed. The gap is to permit constant current (Class A) operation without saturation. Class A is the defau .......
64: Tube DIY Asylum, RE: 6DJ8 vs 12AU7 / 12AT7 (0.00)
Posted by Stuben on 2019-11-13, 16:52:44 (50.5.140.254)
If you're looking for a driver for a project, the 6DJ8 and it's medium Mu cousins will probably work for you. I've found these puppies work well driving IDH pentodes and tetrodes with a little mu requ .......
65: Tube DIY Asylum, RE: I wouldn't bother with an IT in anything (0.00)
Posted by Stuben on 2019-10-24, 14:41:59 (50.5.140.254)
I've used Lundahl IT in both SE and PP. Took a while to figure out the proper H (multiple primaries) and Current in the primaries. I have not measured anything from a phase POV. I can say the sound ul .......
66: Tubes Asylum, RE: "I try to never use transistors" (0.00)
Posted by Stuben on 2019-10-16, 06:57:27 (66.42.231.242)
Depends what your goals are. If it is your goal of "No sand" ever then it directly conflicts with the goal of optimizing performance economically. I have used coscoded Mosfets for plate loading with s .......
67: Tube DIY Asylum, RE: You missed my point, the home is not a women's job (0.00)
Posted by Stuben on 2019-10-09, 08:41:38 (66.42.231.242)
Yes, sir...I like the way you think...nothing like being put on tread mill and you can't remember why... Stuben .......
68: Tube DIY Asylum, RE: I don't know! (0.00)
Posted by Stuben on 2019-09-26, 11:47:54 (66.42.231.242)
I have not drank the time cool aid but could Mr DF be referring to minute DC various created by changing load across the OPT due to the AC element considering there is no such thing as perfect DC. The .......
69: Tubes Asylum, RE: Best El84 (0.00)
Posted by Stuben on 2019-09-21, 10:59:16 (50.5.140.254)
JJ EL84s are a good New stock option. It has been several years since I purchased any. I assume they haven't changed in there construction. Stuben .......
70: SET Asylum, RE: SET fundamentalism is often (0.00)
Posted by Stuben on 2019-09-17, 12:50:06 (66.42.231.242)
Yea, the building in a vacuum thing is problematic. It would greatly benefit everyone, if we all could hear the other's creations. The learning would would be big for all involved. Instead we bicker .......
71: Tube DIY Asylum, RE: Lowering gain in DIY 6L6 amplifier - picture (0.00)
Posted by Stuben on 2019-08-22, 05:19:42 (50.5.140.254)
Wow, is it the summer heat...just recommended a driver to help Pete move away from the guitar amp drivers. The ECC99, 5687, 6sn7s are all superior in most applications where the design accommodates. D .......
72: Tube DIY Asylum, RE: Lowering gain in DIY 6L6 amplifier - picture (0.00)
Posted by Stuben on 2019-08-19, 12:02:45 (50.5.140.254)
Hey Pete Yes, increasing FB with lessen gain. If you rely on a Linestage. Might try a driver with more transconductance and less gain. 12au7 comes to mind. Stuben .......
73: SET Asylum, RE: "It might also run counter to many people's understanding of what makes a nice-sounding amp" (0.00)
Posted by Stuben on 2019-08-11, 06:05:03 (50.5.140.254)
My Living room amp is also a SE KT66 amp with output feedback. I like the sound of the Tetrodes and Pentodes when enough "Taming" is applied. My reference amp is 6a3 IT coupled Mono blocks. The linea .......
74: SET Asylum, RE: 2A3 Direct Coupled VS. Capacitor coupled (0.00)
Posted by Stuben on 2019-07-25, 09:56:21 (66.42.231.242)
Hey TK, Just saw your post. Correct me if I'm wrong:>) but I think it is the RC network that is susceptible to Blocking distortion and a LC would be less susceptible while proving minimal DCR to groun .......
75: Tube DIY Asylum, Interesting stuff (0.00)
Posted by Stuben on 2019-07-17, 16:40:06 (50.5.140.254)
https://phys.org/news/2019-07-first-ever-visualizations-electrical-gating-effects.html Could this be the beginning of devices that can make the Thermonic/Sand Device argument null... Stuben ::: TOPIC: .......
76: Tube DIY Asylum, RE: Choke Loading (0.00)
Posted by Stuben on 2019-07-17, 10:51:57 (66.42.231.242)
Hey TK, Used Chokes with CF for a couple of builds recently. The last preamp prototype uses a pair plate chokes I had laying around. Results are are VERY good. Stuben .......
77: Tube DIY Asylum, RE: Grid choke on pentode or triode? (0.00)
Posted by Stuben on 2019-06-17, 13:12:38 (66.42.231.242)
Generally, Grid chokes can used to load the grids of Triodes or Pentodes depending on the current requirements. I've used them on the input and output sections with good results. Just replace the the .......
78: Tube DIY Asylum, RE: Low Mu's KT-88 update (0.00)
Posted by Stuben on 2019-06-11, 09:17:18 (66.42.231.242)
I have always kept an open mind when it comes to the Power supply touted by Jeff and others. With that said, I'm still a "Critical Inductance" guy. I was at a customer site in the KC area a few years .......
79: Tube DIY Asylum, RE: grid stoppers (0.00)
Posted by Stuben on 2019-03-08, 09:37:48 (66.42.231.242)
Eli, YUP I put a bead on heater wiring also. Probably per your suggestion..been a while. No oscillations that I can hear... Stuben .......
80: Tube DIY Asylum, RE: grid stoppers (0.00)
Posted by Stuben on 2019-03-07, 08:57:50 (66.42.231.242)
Hey Fitz Might need to resort to adding a ferrite bead on the approach to the Grids. Did this on grid connections for the 5842. .......
81: SET Asylum, RE: Advise on SET + single driver setup (0.00)
Posted by Stuben on 2019-02-14, 12:16:44 (66.42.223.245)
Hello fellow Audio crazy.. 1 - Speakers - What single driver options would you consider for around $1,000. I've has my eye on some Omegas (Super 3 XRS enclosure with RS7 drivers, 94.5 dB at 8 ohms). .......
82: SET Asylum, RE: Advise on SET + single driver setup (0.00)
Posted by Stuben on 2019-02-14, 12:09:05 (66.42.223.245)
Hello fellow Audio crazy.. 1 - Speakers - What single driver options would you consider for around $1,000. I've has my eye on some Omegas (Super 3 XRS enclosure with RS7 drivers, 94.5 dB at 8 ohms). .......
83: Tube DIY Asylum, RE: Do you ever listen to equipment made by other DIYers? (0.00)
Posted by Stuben on 2019-02-02, 12:57:17 (66.42.223.245)
Yep and it is golden to have other ears listening to your stuff especially if their willing to honestly critique. Personally, I think we all should be listening and learning from each other which is s .......
84: Tube DIY Asylum, RE: Miller and Feedback and Controls (0.00)
Posted by Stuben on 2019-01-09, 10:46:06 (66.42.223.245)
Hey TK, how about a nice grid choke for the EF86... Stuben .......
85: Tube DIY Asylum, RE: Looking to build an EL-84 power amp (0.00)
Posted by Stuben on 2018-12-31, 09:25:49 (66.42.223.245)
Provides grid load for the input. Low DCR high H for freq response. Can use a resister or input pot. The later might be appropriate with more gain in the section maintaining a 2 stage design.. Stuben .......
86: Tube DIY Asylum, RE: Looking to build an EL-84 power amp (0.00)
Posted by Stuben on 2018-12-30, 13:32:10 (66.42.223.245)
This design needs a preamp to make it worth the trouble. Not an inexpensive build considering the iron involved. You could go with a CCS Plate load on the driver and nix the IT. Might enjoy more gain. .......
87: Tube DIY Asylum, RE: Looking to build an EL-84 power amp (0.00)
Posted by Stuben on 2018-12-30, 09:52:17 (66.42.223.245)
Built This one a few years back. Needs some gain up front to really let the magic out. Great performer otherwise. Stuben .......
88: High Efficiency Speaker Asylum, RE: My hats off to those (0.00)
Posted by Stuben on 2018-11-25, 16:27:22 (66.42.223.245)
Work with the " What is the requirements of my new room" concept and you know how to make yourself happy with sound... .......
89: Tube DIY Asylum, RE: SE 6CB5 with Hammond 126C IT (0.00)
Posted by Stuben on 2018-10-10, 09:24:03 (66.42.231.242)
The 6SN7, IMO is one of the best voltage amps ever as far as sound and ease of implementation. I think it's Rp is a little high for IT service. Give it try, you can always find another octal valve wit .......
90: Tube DIY Asylum, RE: Puzzle for Electrical Geniuses on this forum ...... (0.00)
Posted by Stuben on 2018-10-07, 14:49:58 (66.42.223.245)
Sounds like you are adding a load that challenges the potential enough to drop the whole rail..everybody sucks up big current on startup. Stuben .......
91: SET Asylum, RE: The JBL-L112 and the 2A3 SET.... (0.00)
Posted by Stuben on 2018-08-31, 13:24:45 (66.42.223.245)
Sweet Will, you always inspire...thanks for sharing Stuben .......
92: Tube DIY Asylum, RE: Amp hums on start up (0.00)
Posted by Stuben on 2018-08-03, 08:27:26 (66.42.231.242)
I have a couple of builds that provide a brief low hum on startup. I have attributed this to instability on startup. Both builds have OPT feedback through the secondary of the OPT which I have assumed .......
93: SET Asylum, RE: output transformer recommendation (0.00)
Posted by Stuben on 2018-07-29, 12:25:48 (66.42.223.245)
I've been a Lundahl user for 20 years. Personally, I think you get great performance with a mid-range price. Contact Kevin Carter @ K&K Audio Stuben .......
94: Tube DIY Asylum, RE: 5Y3 rectifier (0.00)
Posted by Stuben on 2018-07-22, 08:57:00 (66.42.223.245)
Hey Ed, The new stocks are ok. You might consider something with less voltage drop provided the amp will permit a little higher b+. I have found the best way to let the magic out of a SE DHT is to put .......
95: Tube DIY Asylum, RE: eBay Caution (0.00)
Posted by Stuben on 2018-07-07, 14:03:14 (66.42.223.245)
Thanks TK I tend to use "Nearest First" ...good information to have. Stuben .......
96: Tubes Asylum, RE: Which would sound better driving a DC coupled 2A3,a Single or a Paralelled section 6SN7 triode, (0.00)
Posted by Stuben on 2018-07-04, 13:42:02 (66.42.223.245)
Hey Willie, Try a CCS a top the first half of the 6SN7. If you go parallel, you can do the same. Kits are plentiful. Stuben .......
97: Tube DIY Asylum, RE: coming full circle with a nice beginners project amp (0.00)
Posted by Stuben on 2018-06-24, 12:18:58 (66.42.223.245)
Hey Vinnie, You've probably mentioned this in the past threads but, what speakers are you driving from an efficiency stand point? I've been running voight pipes with FE206en drivers. I'm probably 90-9 .......
98: Tube DIY Asylum, RE: Yup. (0.00)
Posted by Stuben on 2018-06-24, 12:00:21 (66.42.223.245)
Nice looking gear. I re-cap a Bass man head for a friend, I plugged it into my twin cabinet for a test ride...wow I was tempted to offer a trade for the Twin... Stuben .......
99: Tube DIY Asylum, RE: Preamp Progress (0.00)
Posted by Stuben on 2018-06-21, 04:05:07 (66.42.231.242)
Very Nice TK. Built like a Tank and pretty. ;>) Stuben .......
100: Tube DIY Asylum, RE: how many here (0.00)
Posted by Stuben on 2018-06-18, 14:52:47 (66.42.223.245)
Dude, I would think going away from an octal tube if already implemented wouldn't make a huge amount of sense considering the 6s were replaced by the a 9 pin inferior valve? Stuben .......
101: Tubes Asylum, RE: Need a warm sounding tube for a ARC VT60 (0.00)
Posted by Stuben on 2018-05-22, 11:25:36 (66.42.231.242)
What sources are you using? The amplifier is probably providing an accurate presentation of the what it is receiving up front. In my experience, CD sources can be tamed with a good out board DAC. In m .......
102: Tube DIY Asylum, RE: HDMI pin out??? (0.00)
Posted by Stuben on 2018-05-20, 12:22:17 (66.42.223.245)
HDMI to analog converts are out there...if you are willing to buy from EBAY ....$20.00 or so if memory serves. The converter box will have RCA connected right and left analog signals. Stuben ::: TOPIC .......
103: Tubes Asylum, RE: There needs to be a better way (0.00)
Posted by Stuben on 2018-05-16, 06:58:29 (66.42.231.242)
Hey DAK..couldn't agree more. If this is the best we can do in our experiment with Capitalism, then we are screwed and China will get the last laugh...we have been high jacked by a new type of Neo-Lib .......
104: Tube DIY Asylum, RE: Would you use these chokes? (0.00)
Posted by Stuben on 2018-05-09, 08:42:21 (66.42.231.242)
Very nice chokes...if you are concerned about cost and can you get by with a 300 mA Choke, the Hammond 193M is trending about half that cost. 10h 63ohms. Stuben .......
105: Tube DIY Asylum, RE: 6C45-PE and LL1660/18 (0.00)
Posted by Stuben on 2018-05-08, 07:15:29 (66.42.231.242)
I configured mine for the max primary inductance. The primaries all in series. I used the 1660s/18 SE-PRI PP-SEC. The drivers I'm using are low plate impedance fairly hi transconductance. After sever .......
106: SET Asylum, RE: Power cable for low watt SET amp? (0.00)
Posted by Stuben on 2018-04-30, 09:02:38 (66.42.231.242)
Three pronged work just fine. Unless you can prove a perfect system up stream, you'll never hear it. .......
107: Tube DIY Asylum, RE: Power supply problem (0.00)
Posted by Stuben on 2018-04-15, 12:38:43 (66.42.231.242)
Like others have indicated, check and make sure you have cathodes to ground in some manner...did this once. I then proceeded to use myself to achieve a ground connection...stopped drinking and solderi .......
108: Tube DIY Asylum, RE: Input on first choke in a LCLC PS (0.00)
Posted by Stuben on 2018-04-13, 08:44:15 (66.42.231.242)
Hey Mike, I have used the Hammond 193 M ...10H, 63 ohms 300 mA. Stuben .......
109: Tube DIY Asylum, RE: It's called "absolute phase." (0.00)
Posted by Stuben on 2018-04-06, 08:24:51 (66.42.223.245)
I rotate my amplifiers in and out all the time. It is interesting, the initial listen exposes the differences readily, give it a few minutes and difference are forgotten and replaced by the signature .......
110: Tube DIY Asylum, RE: Good input circuit (0.00)
Posted by Stuben on 2018-04-05, 13:23:26 (66.42.223.245)
Using a CCS loaded 6SN7 with cathode follower from second triode...really like the result .......
111: Tubes Asylum, RE: anyone tried this tube buffer from China? (0.00)
Posted by Stuben on 2018-03-09, 12:09:26 (66.42.223.245)
Can't vouch the line stage but I have their Phono stage. It was DOA. I contacted the seller who informed me the shipping back was not worth his money in so many words. At this point I had the realizat .......
112: Tube DIY Asylum, RE: Yup... (0.00)
Posted by Stuben on 2018-03-06, 07:18:17 (66.42.231.242)
Like others have said...stoppers on all the grids...ferrite bead just up stream. Stuben .......
113: Tube DIY Asylum, RE: LC choke vs resistor (0.00)
Posted by Stuben on 2018-03-05, 08:56:17 (66.42.231.242)
I usually see around 10% drop across a choke input. Stuben .......
114: Tube DIY Asylum, RE: Doug frequently praises triode strapped 6BQ5 and 6CL6... (0.00)
Posted by Stuben on 2018-02-15, 07:06:16 (66.42.231.242)
I have a EL84 Line stage prototype on my bench. Two sections strapped, CCS on the first section plates with a choke load on the cathode. The second section is a CF. The intent is to drive my 50 Mono b .......
115: Tube DIY Asylum, RE: Is there any way to make this sound better? (0.00)
Posted by Stuben on 2018-02-13, 04:56:47 (66.42.231.242)
CCS on top of V1, change V2 to something with a little more transconductance and go CF. Better yet chuck both 12ax7s. The feedback complexity is just that. Stuben .......
116: Tube DIY Asylum, RE: FB question (0.00)
Posted by Stuben on 2018-01-30, 10:14:13 (66.42.231.242)
I've had good results applying Cathode feedback in the output section through the secondary of the OPT. As long as the speaker correction has a Zoebel network. Without the Zoebel shunt, an interestin .......
117: Tube DIY Asylum, RE:The threat of physical violence was all it took, as so often is the case. (0.00)
Posted by Stuben on 2018-01-26, 12:47:49 (66.42.223.245)
Is this sarcasm, or you have a bad connection? .......
118: Tube DIY Asylum, RE: So now I have to trouble shoot a complex speaker crossover (0.00)
Posted by Stuben on 2018-01-25, 07:06:35 (66.42.231.242)
Have you checked interconnects including speaker connections? Simple stuff sometimes is the answer. I assume there are no active components in your crossover..if film caps are used, hard to imagine wh .......
119: Tube DIY Asylum, RE: What tubes does this use? (0.00)
Posted by Stuben on 2018-01-18, 06:40:43 (66.42.231.242)
See if you figure out the Power transformer secondary voltage and the output transformer primary impedance...report back.. Stuben .......
120: Tubes Asylum, RE: 5687 to 6922 tube adapters - eBay (0.00)
Posted by Stuben on 2018-01-07, 16:09:20 (66.42.223.245)
The 5687 is a different animal. Much higher current capabilities and half the MU. Also likes a higher plate voltage than the 6922. Unless you plan on modifying the amp, not a good idea. Stuben ::: TOP .......
121: Tube DIY Asylum, RE: If it was easy, anyone could do it... (0.00)
Posted by Stuben on 2017-11-21, 10:29:31 (66.42.223.245)
I did the same thing on a build I've had on my bench for way too long. I was fortunate enough to be able to modify the driver to get it to work...I think. Would not be acceptable if I were building to .......
122: Tube DIY Asylum, RE: Question for DIYers (0.00)
Posted by Stuben on 2017-11-10, 06:36:14 (66.42.231.242)
Best answer.. .......
123: High Efficiency Speaker Asylum, RE: Silver Speaker Cables with Avantgarde Horns (0.00)
Posted by Stuben on 2017-11-07, 11:51:59 (66.42.231.242)
I sampled a set of Trios years ago and I was a bit surprised by the mid range "Shout" I heard. The amp was a 18 watt 6C33 LAM SET. You have some serious efficiency to deal with...are you looking at th .......
124: Tube DIY Asylum, RE: Built myself a 26 line stage (0.00)
Posted by Stuben on 2017-11-06, 16:10:44 (66.42.223.245)
Looks like Coscoded Mosfets, BTW, WTF is a Gyrator, is it a kin to a vibrator? Stuben .......
125: Tube DIY Asylum, RE: Projects built by Ken_ (0.00)
Posted by Stuben on 2017-11-03, 09:04:23 (66.42.231.242)
Been posting here on and off for about 15 years, would you know if Ken had a SET forum moniker ? Stuben .......
126: Tube DIY Asylum, RE: How does CCS plate load sound vs Resistor load (0.00)
Posted by Stuben on 2017-10-29, 12:07:30 (66.42.223.245)
Were you have room and $$, the plate choke is a much better alternative To resister. One day I will set up a resister / sound comparison in the same application .......
127: Tube DIY Asylum, RE: 6L6G SE amp schematic (0.00)
Posted by Stuben on 2017-10-26, 13:39:30 (67.207.103.2)
TK, Agreed, my ears prefer no UL at least for my PP builds. It has been so long since I tried UL on SEP build, I don't recall the sound...:>) Stuben .......
128: Tube DIY Asylum, RE: 6L6G SE amp schematic (0.00)
Posted by Stuben on 2017-10-26, 13:33:22 (67.207.103.2)
Have look at how Claus Byrith designed a nice SEP amp. http://www.lundahl.se/wp-content/uploads/datasheets/cb-amplifier_8wse.pdf I implemented the output feedback scheme described on a PP build and ne .......
129: Tube DIY Asylum, RE: How does CCS plate load sound vs Resistor load (0.00)
Posted by Stuben on 2017-10-17, 16:30:21 (70.213.17.34)
Beats the hell out of a resister, and it gives you more flexibility because you have more plate voltage to work with if you want to explore different valves for the application. The sound only gets be .......
130: SET Asylum, RE: I have neither the experience or knowledge of the Serious Stereo amplfiers, but... (0.00)
Posted by Stuben on 2017-10-13, 06:30:45 (66.42.231.242)
Everyone has different ears and criteria for "Good Sound" or fidelity of the reproduction. There are absolute truths in engineering design. The truths get us to the table as far as achieving this ext .......
131: SET Asylum, RE: ... 265Vp and 38ma across the Plate of a W.E. VT-52 ..... (0.00)
Posted by Stuben on 2017-10-13, 05:15:58 (66.42.231.242)
Will, I have three Sylvania VT-52s, I don't have enough efficiency speaker drivers to really let the magic out. I use 50s instead. So I've heard the WE versions have higher plate dissipation? I think .......
132: Tube DIY Asylum, RE: Series Filaments - Why Not? (0.00)
Posted by Stuben on 2017-10-11, 10:45:08 (66.42.231.242)
Hey TK, It is just about series reliance of the two valves. You can't assume they are at the same voltage as they age and during warm up... Have at it and run them in series for a while...chances are .......
133: Tube DIY Asylum, RE: welcome to the club (0.00)
Posted by Stuben on 2017-10-05, 09:20:26 (66.42.231.242)
On my first IT build, I tied the wrong polarity together in the loop. Sent a sketch to Kevin Carter who chuckled when he saw it. I'm a 30 year controls engineer who should see current loops in their s .......
134: Tubes Asylum, RE: Psvane EL34 impressions? (0.00)
Posted by Stuben on 2017-09-27, 07:16:34 (66.42.231.242)
In my gear the Mullard new stock sounds better. .......
135: SET Asylum, RE: Don Allen Amplifier Questions (0.00)
Posted by Stuben on 2017-09-24, 15:19:54 (66.42.223.245)
Jeff, If you have the efficiency down stream, You will probably be pleased with the choice. Stuben .......
136: Tube DIY Asylum, RE: Priorities (0.00)
Posted by Stuben on 2017-09-18, 09:10:29 (66.42.231.242)
I'm with you TK, you have to get your hands dirty to participate in the most meaningful ways in this forum. From building, we learn one valuable thing, We are working with a very dynamic system with m .......
137: Tube DIY Asylum, RE: Ok, i understand that better now. (0.00)
Posted by Stuben on 2017-08-18, 04:04:15 (66.42.231.242)
I was re-building an Zenith SE EL84 amp many moons ago. I neglected to re-install this resister...the plates went rosy red post hast on start up:>) This was one of my learning experiences.. Stuben ::: .......
138: Tube DIY Asylum, RE: Paralleling KSG Silver Mica Caps (0.00)
Posted by Stuben on 2017-07-21, 08:03:59 (66.42.231.242)
Try and have a listen. Don't take our word for it. .......
139: Tube DIY Asylum, RE: what's the best stopper approach to avoid trouble with 5842q? (0.00)
Posted by Stuben on 2017-07-19, 12:28:22 (66.42.231.242)
I implemented the same for my builds. Stopper on all 4 grids and a ferrite bead on the heater. No audible issues. Stuben .......
140: Tube DIY Asylum, RE: Type 45 tube comparison (0.00)
Posted by Stuben on 2017-07-12, 09:37:54 (66.42.231.242)
I run the same configuration with 50s. One day, I will up grade my speakers to accommodate. Stuben .......
141: Tube DIY Asylum, RE: Installing a current meter.. (0.00)
Posted by Stuben on 2017-07-02, 07:16:08 (50.5.143.176)
I would think placing a measuring device in the loop might be a bad idea. Just thinking about it's potential for adding color.. but a calc off a know voltage drop would be less intrusive. ..might be o .......
142: Tube DIY Asylum, RE: how to remove feedback loops (0.00)
Posted by Stuben on 2017-06-12, 14:39:35 (50.5.128.225)
One thing for got mention, maybe someone else did...removing the loop will negate some of voltage requirements for the front end which is there to accommodate the FB Loop, so you can back down the dis .......
143: Tube DIY Asylum, RE: how to remove feedback loops (0.00)
Posted by Stuben on 2017-06-12, 14:25:05 (50.5.128.225)
Vinnie, Remove the feedback loop, put a nice solid voltage on G2, run your cathodes through the opt secondaries to ground for cathode feedback, you still need the resistance up or down stream of your .......
144: SET Asylum, RE: Is an SET Amp or Some Variation complementary with my Speakers? (0.00)
Posted by Stuben on 2017-05-24, 13:47:36 (50.5.128.225)
I concur with the "Get more efficient drivers or look at a nice Pentode build". They are out there. I can't think of a practical SET solution unless you have $$ and are willing to work with HV. Even t .......
145: SET Asylum, RE: whats Better dynamically better quality but smaller or large awg?? (0.00)
Posted by Stuben on 2017-03-26, 06:25:29 (104.231.33.166)
My day job involves the design of Automation systems that pass data back and forth. Sold core conductors have a higher band width than stranded. We like to use stranded because it is more robust to in .......
146: Tube DIY Asylum, RE: And who are you? (0.00)
Posted by Stuben on 2017-03-16, 16:04:22 (104.231.33.166)
Guys, Things go south when folks speak IN ABSOLUTES. We all do things that might not align with bottom line design but most don't swear it's the only way...especially in DIY. Being sold faith leaves .......
147: Tube DIY Asylum, RE: O/T Squirrel proof bird feeder (0.00)
Posted by Stuben on 2017-03-14, 12:18:15 (66.42.231.242)
I have used a 3/32 stranded cable. Hang the feeder at least 8 feet from the nearest tree trunk and 7 feet from the ground. No flying rodent issues. Stuben .......
148: Tube DIY Asylum, RE: who uses different wire colors in amps? (0.00)
Posted by Stuben on 2017-03-05, 06:32:06 (104.231.33.166)
I tend to use green for Earth, Black for line and Red for everything down stream of the Power secondaries. I do go RED/BLK on the OPT secondaries. There are exceptions, when I run out of particular co .......
149: SET Asylum, RE: In my direct-coupled 45 amp....some observations (0.00)
Posted by Stuben on 2017-03-04, 09:53:20 (104.231.33.166)
Jeff, Tight build... Kinda off thread but ...do you take the ESR of each cap into consideration when you parallel capacitors ? Stuben .......
150: Tube DIY Asylum, RE: Question for Aikido linestage (0.00)
Posted by Stuben on 2017-03-02, 16:38:58 (104.231.33.166)
Guys, From a sound point of view, what are ya hearing. Thinkin about building one on my proto board. Stuben .......
151: Tube DIY Asylum, RE: multimeter is reading very high plate current (0.00)
Posted by Stuben on 2017-02-20, 12:06:59 (66.42.231.242)
Might be a stupid question....do you know the DCR for the LED? Never used one...I'm sure those who have will chime in. Stuben .......
152: Tube DIY Asylum, RE: Do russian teflon capacitors lack musicality? (0.00)
Posted by Stuben on 2017-02-20, 09:59:52 (66.42.231.242)
A good outboard DAC helps a lot. Just use the CD player as a transport. Stuben .......
153: Tube DIY Asylum, RE: It's all about the design and build. To isolate one particular component requires a perfect platform...doesn't (0.00)
Posted by Stuben on 2017-02-19, 07:05:06 (104.231.33.166)
BTW, I have used the Russian Military Teflons. Very Nice results. I like em.. Stuben .......
154: Tube DIY Asylum, RE: It's all about the design and build. To isolate one particular component requires a perfect platform...doesn't (0.00)
Posted by Stuben on 2017-02-19, 06:57:07 (104.231.33.166)
With all that said, you can hear the differences in passive devices, particularly caps and output transformers of varying build and quality. I interpreted the term "Musicality" as a system attribute. .......
155: Tube DIY Asylum, RE: Do russian teflon capacitors lack musicality? (0.00)
Posted by Stuben on 2017-02-17, 08:19:11 (66.42.231.242)
It's all about the design and build. To isolate one particular component requires a perfect platform...doesn't happen...keep tweaking.. Stuben .......
156: Tube DIY Asylum, RE: What can you build with a 50mA 5k SE output transformer? (0.00)
Posted by Stuben on 2017-02-15, 12:37:02 (66.42.231.242)
I'm running them as delicate as reasonable ...about 4-5 watts of very big sound. I have had difficulty driving them. I have a prototype EL84 line stage that is getting the job done finally. The monos .......
157: Tube DIY Asylum, RE: What can you build with a 50mA 5k SE output transformer? (0.00)
Posted by Stuben on 2017-02-15, 07:02:08 (66.42.231.242)
I use a Lundahl LL1663 for my 50 monoblocks.... If you want to dive into the world of valves on the rare side...I've picked up 5 RCA balloon 50s over the last decade to support...If I had it to do aga .......
158: Tube DIY Asylum, RE: Would Volt regulator IC contribute harsh sound(IMD) ? (0.00)
Posted by Stuben on 2017-02-09, 14:12:09 (104.231.33.166)
Eric, Sorry, my memory had a hickup...the 6C33C amp that referred to was a LAMM product. Stuben .......
159: Tube DIY Asylum, RE: Would Volt regulator IC contribute harsh sound(IMD) ? (0.00)
Posted by Stuben on 2017-02-09, 04:25:49 (66.42.231.242)
Eric, You might consider having an over all look at your system. Gain,impedance matching between Pre and Power Amp, damping factor between your Power Amp and Speakers...etc. The last 6c33c amp I heard .......
160: Tube DIY Asylum, RE: 5687 preamp (0.00)
Posted by Stuben on 2016-12-24, 11:21:38 (104.231.33.166)
I started with the simple design. I had a terrible time with noise. Ended up on the second iteration with a 5687 CCS loaded into a Parafeed arrangement with LL1674 opt and a nice Parafeed cap. The LL1 .......
161: SET Asylum, RE: DIY SET, LAYOUT - keep short return paths to Ground (0.00)
Posted by Stuben on 2016-08-20, 13:47:09 (104.231.33.166)
Jeff, Looks nice. I tend to heat mechanical connections up and fill with solder from experience with intermittent connections...especially earthing. Stuben .......
162: K&K Audio / Lundahl Transformers, RE: Start up and shut down noise (0.00)
Posted by Stuben on 2016-08-03, 10:05:41 (66.42.231.242)
Kevin, Thanks, I was running the Push Pull build for years in my basement sound room driving a DIY set of speakers with FE207s, a tweeter with a simple baffle correction. Never had any issues other th .......
163: K&K Audio / Lundahl Transformers, Start up and shut down noise (0.00)
Posted by Stuben on 2016-08-02, 10:45:31 (66.42.231.242)
Kevin, Been a while since I have posted. I have been working on several PPP and CFSEP projects. I have been able to achieve some good results sonically but I have had some interesting oscillations (we .......
164: Tube DIY Asylum, RE: Paul Carlson has a really good video on this..Here it is. (0.00)
Posted by Stuben on 2016-07-25, 15:04:03 (104.231.33.166)
Great stuff Mike ...thanks sir .......
165: Tubes Asylum, RE: New Production EL84 comparison thread, please participate!! (0.00)
Posted by Stuben on 2016-07-23, 10:03:01 (104.231.33.166)
MBS, I can only contribute with a plug for the New stock JJ's. Never been disappointed using them in my own builds. Stuben .......
166: Tube DIY Asylum, RE: I think I will put this on the coffee table as a conversation piece... (0.00)
Posted by Stuben on 2016-07-23, 06:40:05 (104.231.33.166)
Vinnie, Got to ask ..have you been bitten lately, if you haven't you are asking for it....be careful Stuben .......
167: SET Asylum, RE: PSE 6C33C Monoblocs (0.00)
Posted by Stuben on 2016-05-10, 14:15:28 (104.231.33.166)
Muck, Looks great. Kevin has been my goto supplier on signal components for better part of 15 years. Good Dude. Stuben .......
168: Tube DIY Asylum, RE: Advice on safe troubleshooting method please (0.00)
Posted by Stuben on 2016-02-07, 14:17:22 (104.231.33.166)
Joris, Were you listening at the time? Stuben .......
169: Tube DIY Asylum, RE: round and round we go .......... (0.00)
Posted by Stuben on 2016-01-24, 06:14:33 (104.231.33.166)
The numbers you trying to nail down put you in middle of linear region of the load line...you have some wiggle...your ears might ultimately change it again. Great work...you've inspired me to look at .......
170: Tube DIY Asylum, RE: 417A linestage (0.00)
Posted by Stuben on 2016-01-23, 06:20:29 (104.231.33.166)
Tubestein, Build it and see that you bud is talking about....never been a fan of paralleling. Keep in mind that the 5842/417a has (4) grids and you need to provide stoppers for all. These voltage amps .......
171: Tube DIY Asylum, RE: Here we go again........ (0.00)
Posted by Stuben on 2016-01-06, 08:49:08 (66.42.231.242)
CCS Load the 26, drive a CCS loaded 45 with a grid choke in front of the 300B. I assume you're looking to go all DHT.. Stuben .......
172: Tube DIY Asylum, RE: Grounding (0.00)
Posted by Stuben on 2015-12-27, 10:18:32 (104.231.33.166)
Tom, The fuse might not even see additional current...if the chassis and B+ come together without a SAFETY / Equipment ground. (third prong) they are at the same potential...you just have a hot chassi .......
173: Tube DIY Asylum, RE: CCS on 76 Triode (0.00)
Posted by Stuben on 2015-12-27, 07:00:50 (104.231.33.166)
I have had good results loading triodes and you will get a MU benefit. For a twelve dollar kit, can't go wrong with additional learning as another perk... Stuben .......
174: SET Asylum, RE: Ok to mix different cathode film caps in a SET? (0.00)
Posted by Stuben on 2015-12-27, 06:16:54 (104.231.33.166)
I have always wondered what the implications of paralleling capacitors of different ESR capabilities....does not seem like a great approach. I have tried paralleling speaker crossover caps with no rea .......
175: Tubes Asylum, RE: "The Tube Hums At Midnight" and other radio mysteries (0.00)
Posted by Stuben on 2015-12-12, 09:15:29 (104.231.33.166)
You could be dealing with an oscillation situation, the newer tubes might have a slightly stronger transconductance... I have had oscillations cleverly disguised as Hum :>) Stuben .......
176: Tube DIY Asylum, RE: That's not a differential input (0.00)
Posted by Stuben on 2015-12-09, 08:56:53 (66.42.231.242)
Come on TK, Try it...your ears will like it ;>) .......
177: Tube DIY Asylum, RE: Power transformers do not interact with themselves (0.00)
Posted by Stuben on 2015-12-08, 14:10:09 (104.231.33.166)
Chip Thank You Stuben .......
178: Tube DIY Asylum, RE: Question - HOW to find uniform polarity of multiple power transformers in an audio amplifier ?? (0.00)
Posted by Stuben on 2015-12-04, 13:10:24 (104.231.33.166)
Curious, so what if having these sources out of phase actual cancels unwanted ripple or harmonics? I fail to see the connection between AC heated cathodes and the DC they are exciting unless we are co .......
179: Tube DIY Asylum, RE: The case of the squealing amp (0.00)
Posted by Stuben on 2015-11-25, 15:46:39 (104.231.33.166)
hey 91 Tidy up the internal connections with some shielded cables, ground the shield on one side only. Make sure you have grid stops on all grids. Sounds like parasitic oscillations... Have fun Stuben .......
180: Tube DIY Asylum, RE: Level 5 2A3 SE Design (0.00)
Posted by Stuben on 2015-11-01, 09:02:20 (104.231.33.166)
Hey Lovetube.. I used the Coscoded mosfet kit that K&K offers...probably should work out a home grown, but these guys are decent quality and cheap..hard to resist. Stuben .......
181: Tube DIY Asylum, RE: Level 5 2A3 SE Design (0.00)
Posted by Stuben on 2015-10-30, 12:48:22 (104.231.33.166)
I have really enjoyed the sound of my 6sn7s loaded with CCS. To my ears the the high end improves. If the 6sn7 has a negative, it can provide too much second order in a conventional loading configurat .......
182: Tube DIY Asylum, RE: triode strap d3a:can wire wound plate resistor cause oscillation ? (0.00)
Posted by Stuben on 2015-10-25, 06:23:44 (104.231.33.166)
Just added a 100 ohm non-inductive to my plate connections on one of my builds that has a oscillation tendency...so far so good. Stuben .......
183: Tube DIY Asylum, RE: Geraldine SE KT88 - New Build (0.00)
Posted by Stuben on 2015-10-21, 12:42:33 (66.42.232.242)
Nice build...please cover those plate conductors....It's a nice conversation piece but a bit risky especially for strangers, kids and pets ;>) How does the strapped KTs sound? Stuben .......
184: Tube DIY Asylum, RE: What's in the cupboard that should be in your amp? (0.00)
Posted by Stuben on 2015-10-02, 09:02:26 (66.117.237.162)
Andy, I have found that derating your PS chokes by 100% while maintaining critical inductance will yield a lower impedance supply providing a superior sound. I'm sure the parallel rectifier service is .......
185: Tube DIY Asylum, RE: Amp build: layout questions (0.00)
Posted by Stuben on 2015-09-14, 11:21:04 (66.117.237.162)
There looks like ample distance if you build like depicted in the link. If you you don't have the stack up, put the heat producers on top... Stuben .......
186: Tubes Asylum, RE: 6H30 tube drop in replacement ???? (0.00)
Posted by Stuben on 2015-09-12, 12:41:37 (104.231.33.166)
I roll a Siemens E288cc in place of my 6H30 from time to time. The better quality 6H30s sound better to me. Stuben .......
187: Tube DIY Asylum, RE: Help: tranny AC voltage to rectifty and get 6.3 volts? (0.00)
Posted by Stuben on 2015-09-09, 08:38:44 (66.117.237.162)
You really don't need to go to this trouble for IDH valves.I'm running fairly high gain cascaded 6SN7s with no hum...put your energy somewhere else in the design.... Stuben .......
188: Tubes Asylum, RE: Sophia 6SN7 (0.00)
Posted by Stuben on 2015-08-26, 13:59:41 (104.231.33.166)
Stator_99, The 6SN7 is definitely one of the best all around voltage amps. Good linearity and musical. Lots of NOS valves out there still...prices have continued to creep up As far as your chances o .......
189: Tube DIY Asylum, RE: You need a good quality heater supply (0.00)
Posted by Stuben on 2015-08-03, 07:16:40 (66.117.237.162)
Vinnie, I just received a quote from Rod for a couple of his regulators. Use the Bartola web site as suggested. A lot of the Inmates have used the Hammond 156C to load the 26 plates with good results. .......
190: Vinyl Asylum, RE: Yaoin MS-22B Phono preamp 115/230 switch (0.00)
Posted by Stuben on 2015-06-15, 09:27:04 (66.117.237.162)
John, Good to hear. The build is solid. I just need to get this unit operational. Look forward to having a listen...I'll post my impressions.... Thanks Stuben .......
191: Vinyl Asylum, RE: Yaoin MS-22B Phono preamp 115/230 switch (0.00)
Posted by Stuben on 2015-06-15, 07:17:45 (66.117.237.162)
While we're on the subject, how do like the performance of this phono preamp? Stuben .......
192: Vinyl Asylum, RE: Yaoin MS-22B Phono preamp 115/230 switch (0.00)
Posted by Stuben on 2015-06-15, 07:10:03 (66.117.237.162)
John, Thanks. I got my hands on fixer upper. the 115/230 switch seems buggered up. No power when in 115 position. I removed the 115/230 switch and wired the primaries for 230 and measured and then w .......
193: Vinyl Asylum, RE: Yaoin MS-22B Phono preamp 115/230 switch (0.00)
Posted by Stuben on 2015-06-14, 08:37:38 (104.231.33.166)
So no one out there owns one of these units and has a DVM?? :>) Stuben .......
194: Tube DIY Asylum, RE: Yaoin MS-22B Phono preamp 115/230 switch (0.00)
Posted by Stuben on 2015-06-12, 17:18:37 (104.231.33.166)
Got my hands on a fixer upper. In the 115 position, the primaries are open, in the 230 position, I get 67 ohms which should mean (2) 33.5 ohm primaries. I removed the 115/230 switch and wired the prim .......
195: Vinyl Asylum, Yaoin MS-22B Phono preamp 115/230 switch (0.00)
Posted by Stuben on 2015-06-12, 15:26:00 (104.231.33.166)
Guys, Messing with the 115/230 switch on a Yaoin MS-22B phono preamp. Can someone, who owns one, measure the DC resistance between the N and L of the AC receptacle (power disconnected;>) ??? In the st .......
196: Tube DIY Asylum, RE: Yaoin MS-22B Phono preamp 115/230 switch (0.00)
Posted by Stuben on 2015-06-12, 15:21:03 (104.231.33.166)
Sorry Guys, in the states ....115 VAC Stuben .......
197: Tube DIY Asylum, Yaoin MS-22B Phono preamp 115/230 switch (0.00)
Posted by Stuben on 2015-06-12, 15:15:40 (104.231.33.166)
Guys, Messing with the 115/230 switch on a Yaoin MS-22B phono preamp. Can someone, who owns one, measure the DC resistance between the N and L of the AC receptacle (power disconnected;>) ??? Thanks St .......
198: Tube DIY Asylum, RE: Pentode vs. Ultra Linear (0.00)
Posted by Stuben on 2015-04-19, 14:11:13 (184.57.250.166)
Pentode Mode .......
199: SET Asylum, RE: The Amazing W.E. VT52.... the flipside ! (0.00)
Posted by Stuben on 2015-03-25, 09:24:34 (66.117.237.162)
I built a couple of mono block SE VT-52 amps IT coupled driven by 5842s. I couldn't get he magic out because my speakers are not quite efficient enough (around 94db/watt) I used Sylvania VT-52s. I fin .......
200: Tube DIY Asylum, RE: Custom Chassis Suppliers (0.00)
Posted by Stuben on 2015-01-31, 06:46:53 (184.57.250.166)
Hey sony6060 Some of the guys have used this outfit: http://www.frontpanelexpress.com/index.html?gclid=CKG03sa9vsMCFRAzaQodRVIA2A I bought a Greenlee on Ebay a few years ago...that with a stepped bit, .......
201: Tube DIY Asylum, RE: Anyone familiar with K & K audio kits ? (0.00)
Posted by Stuben on 2015-01-16, 16:37:06 (184.57.250.166)
used a few of K&K's CCS kits. Always happy with Kevin Carter's stuff. Good support to boot. Stuben .......
202: SET Asylum, RE: "Dennis Fraker sounds nuts." (0.00)
Posted by Stuben on 2015-01-05, 14:12:28 (184.57.250.166)
I'm guilty of using Velcro...I'll keep you posted as far as reliablity Stuben .......
203: Tube DIY Asylum, RE: Custom 6H30 Linestage project (0.00)
Posted by Stuben on 2014-12-31, 12:51:57 (184.57.250.166)
Very Nice thought out work. Was the elevated preamp filament ground a response to a hum issue or did you go with it out of the box?? Stuben .......
204: Tube DIY Asylum, RE: Custom 6H30 Linestage project (0.00)
Posted by Stuben on 2014-12-31, 12:34:35 (184.57.250.166)
What is driving your 2a3s...? The reason I'm asking is that I have a 5687 Line stage in service that I'm thinking about coupling to my 50,6a3 monos. I'm using 5842s as drivers on my monos.. Stuben ::: .......
205: Tube DIY Asylum, RE: What if....... (0.00)
Posted by Stuben on 2014-12-31, 12:21:49 (184.57.250.166)
My bad, no offence intended. You have brought some new energy into the forum...or at least I have just started noticing...could be that I have stared paying more attention the forum lately. Your posts .......
206: Tube DIY Asylum, RE: What if....... (0.00)
Posted by Stuben on 2014-12-31, 08:02:29 (184.57.250.166)
Well I guess I should have taken a closer look at the schematic..the plate voltages don't look too hateful... You will need to throw a butt load of gain in front of that amp to get the magic out...I s .......
207: Tube DIY Asylum, RE: What if....... (0.00)
Posted by Stuben on 2014-12-31, 07:57:35 (184.57.250.166)
Vinnie, IMHO, the aspect of Sakuma's work that is fascinating is his approach to power and signal grounding...that is frigging art. I like the sound of IT coupling over RC coupling. With that said, i .......
208: Tube DIY Asylum, RE: What if....... (0.00)
Posted by Stuben on 2014-12-30, 12:16:16 (66.117.237.162)
Vinnie, For the CF implementation, instead of going to ground after your output tube bias resister, connect it to the top of the secondary winding of you OPT and make sure the OPT secondary is grounde .......
209: Tube DIY Asylum, RE: Custom 6H30 Linestage project (0.00)
Posted by Stuben on 2014-12-30, 06:16:37 (66.117.237.162)
Ward, That is beautiful. I use the 6h30p to drive my ITs in the PPP amp. Love this driver. The Russian military version is exceptional...I have also used the Sovtek version which IMHO is respectable. .......
210: Tube DIY Asylum, RE: What if....... (0.00)
Posted by Stuben on 2014-12-30, 06:12:08 (66.117.237.162)
Vinnie, It would be a neat project. I'm using Lundahl ITs for my EL84 PPP amp. If you don't plan to Triode strap the EL84s, you will need to tame the Pentode down with with some local feedback on the .......
211: Tube DIY Asylum, RE: Pas 2/3 RIAA (0.00)
Posted by Stuben on 2014-12-29, 06:14:54 (66.117.237.162)
Thanks Peter, I have a PAS2 that I use to drive my triode amps. I have no issues with the Phono sound which give me no reason to start scratching at scabs. Good bang for the buck as far as I'm concer .......
212: Tube DIY Asylum, RE: If the output is meant to be pentode, then... (0.00)
Posted by Stuben on 2014-12-28, 11:21:40 (184.57.250.166)
With the use of the local cathode feedback, the Pentode linearity is improved along with dampening. To what extent the feedback works to get you to "HiFI" , is a function of the system . Provided the .......
213: Tube DIY Asylum, RE: no (0.00)
Posted by Stuben on 2014-12-24, 12:54:38 (184.57.250.166)
Read through Lynn's stuff a few years ago, continue to go back now and then. I can't help thinking we're banging on a link in a chain as far as the PS caps...I ,like most, have evolved from Electrolyt .......
214: Tube DIY Asylum, RE: OPT secondary in cathode circuit ... (0.00)
Posted by Stuben on 2014-12-23, 07:05:06 (66.117.237.162)
We were just kicking around this local feedback scheme recently. http://www.audioasylum.com/forums/tubediy/messages/23/234438.html Normally apply your cathode resistance and then ground through the se .......
215: SET Asylum, RE: Blog of my Audio Note Kit 1 build... (0.00)
Posted by Stuben on 2014-12-19, 12:36:47 (184.57.250.166)
Steve, You have a real talent to able to build and write well to boot. Very Cool Good looking kit. I'm a little confused by the location of the PS chassis penetrations. You will get many years of Musi .......
216: SET Asylum, RE: deciding on SET over push pull (0.00)
Posted by Stuben on 2014-12-19, 04:33:16 (66.117.237.162)
I would maintain the PP amp and work into a less expensive SET amp to start. I personally, like both depending on the music I'm playing and mood. I use my Pentode based PP as my work horse and bring .......
217: Tube DIY Asylum, RE: What's your favorite brand of filter choke and why? (0.00)
Posted by Stuben on 2014-12-18, 17:21:11 (184.57.250.166)
Hey Vinnie, Thought I'd chime in late... I have used the Hammond offering for well over a decade mainly because I've been able to achieve my goals using them after some experience. I typically de-rate .......
218: Tube DIY Asylum, RE: Lundahl LL1620cfb (0.00)
Posted by Stuben on 2014-12-18, 11:23:13 (66.117.237.162)
I didn't answer you questions about using one of the eight primary windings. I can't say with certainty but... I would guess that unless the primaries are designed with additional inductance, you wou .......
219: Tube DIY Asylum, RE: Lundahl LL1620cfb (0.00)
Posted by Stuben on 2014-12-18, 10:59:58 (66.117.237.162)
Yes, the feedback is coming from the secondary. It is another variation of CF. At the end of the day, we're trying to make a Pentode more linear using local Cathode feedback as opposed to global feedb .......
220: Tube DIY Asylum, RE: Lundahl LL1620cfb (0.00)
Posted by Stuben on 2014-12-18, 06:50:42 (66.117.237.162)
Yep the secondary of the LL1682 is 1/2 ohm... In light that you're not relying on the winding as a bias load, not an issue. Just local output feedback...IT coupled amps are really not suitable for glo .......
221: Tube DIY Asylum, RE: Lundahl LL1620cfb (0.00)
Posted by Stuben on 2014-12-18, 05:08:42 (66.117.237.162)
You will need to bias your output normally a then place the feedback windings between your bias resisters and ground. The old classic Quad monos used a CF winding in the primaries..seems like Mac also .......
222: Tube DIY Asylum, RE: Lundahl LL1620cfb (0.00)
Posted by Stuben on 2014-12-17, 15:12:20 (184.57.250.166)
Here's an example... .......
223: Tube DIY Asylum, RE: Lundahl LL1620cfb (0.00)
Posted by Stuben on 2014-12-17, 14:48:55 (184.57.250.166)
The article is not for an SET. It for a single ended Pentode design. Not sure what your'e reading...have another look. Stuben .......
224: Tube DIY Asylum, RE: Lundahl LL1620cfb (0.00)
Posted by Stuben on 2014-12-17, 10:11:22 (66.117.237.162)
Hey sony6060 I haven't tried the Lundahl CF offering but there is an article on the K&K audio web site by Claus Byrith describing this approach using the secondary of a conventional LL1664 OPT. http:/ .......
225: SET Asylum, RE: If I did not know better (0.00)
Posted by Stuben on 2014-12-17, 08:09:21 (66.117.237.162)
GEO, I'm a big Harvey Rosenburg (Dr Gizmo) fan. Not because he was the end all of knowledge but because he had a great sense of humor and he had a great appreciation for the pursuit of "Musical Ecstas .......
226: SET Asylum, RE: Advice on getting a 45 built (0.00)
Posted by Stuben on 2014-12-16, 11:51:11 (66.117.237.162)
Well This is the SET forum and not the DIY...My bad. Many say the DC coupled amps are quite magical.. Check out Paul Joppa's thread on the DC coupled 2a3. Very generous guy... Stuben .......
227: SET Asylum, RE: Advice on getting a 45 built (0.00)
Posted by Stuben on 2014-12-16, 11:27:55 (66.117.237.162)
Hey TAdams, Just a couple of questions and observations: 1. Is this your first build? If yes, please do a web search on safe practices..can't enjoy your work if you're lying dead in a puddle of piss. .......
228: SET Asylum, RE: Power Supply Cap (0.00)
Posted by Stuben on 2014-12-15, 16:26:50 (184.57.250.166)
GargOyle, No need for correction http://farside.ph.utexas.edu/teaching/302l/lectures/node46.html As I've mentioned before, the big oil caps are very good for the money. If prototyping, use em...unless .......
229: SET Asylum, RE: Scotch PS Caps (0.00)
Posted by Stuben on 2014-12-15, 16:01:35 (184.57.250.166)
Just build an isolated bracket for mounting unless you use your chassis as ground which is an art to itself..it would be cool to hear them... Stuben .......
230: SET Asylum, RE: Its finger TAP - TAPPING time !!! Thanks !! (0.00)
Posted by Stuben on 2014-12-15, 15:52:21 (184.57.250.166)
Dennis, Thanks...I truly regret getting this wave of silliness (bad energy) started although Jeff was asking for report... I don't necessary subscribe, but I do understand...only because our sound is .......
231: Tube DIY Asylum, RE: It sounded like utter crap! (0.00)
Posted by Stuben on 2014-12-15, 12:54:35 (66.117.237.162)
Lot's of variables....room, impedance matching and don't dismiss a nasty source from the CD player. I eventually, bought out board DACs for my systems...the average CD D/A are total crap. Drove me cra .......
232: SET Asylum, RE: Motor Run Caps for the BB Proof Amp (0.00)
Posted by Stuben on 2014-12-14, 12:05:34 (184.57.250.166)
Jamie, Keep us posted, my prototype board is available...you guys are inspiring me to start slinging solder this winter...great stuff. Stuben .......
233: SET Asylum, RE: 1KV DC Link Cap (0.00)
Posted by Stuben on 2014-12-14, 09:29:38 (184.57.250.166)
Jamie, I haven't used the WIMA offering but folks on the forum speak highly of the product. I did notice that the 5V4 data sheets that I dug up states a max C1 of 32 uf...I'm sure Paul knows this rect .......
234: SET Asylum, RE: Motor Run Caps for the BB Proof Amp (0.00)
Posted by Stuben on 2014-12-14, 06:37:14 (184.57.250.166)
Hey Steady, I have used these caps in several of my builds and I have never regretted it... http://www.partsconnexion.com/capacitor_film_asc_main.html Yea you can spend a lot of money on caps...I woul .......
235: Tube DIY Asylum, RE: Looking for some help (0.00)
Posted by Stuben on 2014-12-08, 16:24:00 (184.57.250.166)
Hey David, Unless you're dead set on not using solid state devices, I'd suggest an easy to build coscoded mosfet CCS kit for the tail of your divider.Just to save your sanity for more important challe .......
236: Tube DIY Asylum, RE: Interstages and grid load resistors??? (0.00)
Posted by Stuben on 2014-12-08, 08:55:49 (66.117.237.162)
Mike, Did you get this scheme form Mr. Ciuffoli's web site? I have not been there in a few years. His interesting work inspired to try Lundahl Iron. Cool stuff...of coarse AM core interstage will put .......
237: SET Asylum, RE: Its finger TAP - TAPPING time !!! Thanks !! (0.00)
Posted by Stuben on 2014-12-07, 13:08:46 (184.57.250.166)
Jeff, This might be an already worn out question...apologies if it is... Have you determined a correlation between the frequency match and bias? Interesting stuff.. Just keeping an open mind but I'm .......
238: Tube DIY Asylum, RE: Square waves (0.00)
Posted by Stuben on 2014-12-01, 14:56:02 (184.57.250.166)
When I was working out my choke input DC supplies, I started with a square edge and finally ended with a very small potential sine wave. I did hear the difference in this instance.. I love the thought .......
239: Tube DIY Asylum, RE: Ultrasonic heating: success and failure.... (ping Triode_kingdom and Alex Kittic) (0.00)
Posted by Stuben on 2014-12-01, 08:45:05 (66.117.237.162)
Joris, Neat stuff. nice work. It be interesting hear the sonic difference between this approach and regular AC heating (ignoring the hum)... In my experience, those square edges will be a liability. C .......
240: SET Asylum, RE: Maxing Out my 2A3 amp's Power Transformer (0.00)
Posted by Stuben on 2014-11-26, 06:50:49 (66.117.237.162)
Jeff, There are definite advantages to ensure the lowest impedance possible in your secondaries. I like Power trannys with multiple secondary windings that enable you to parallel to reduce impedance. .......
241: SET Asylum, RE: Decipher This (0.00)
Posted by Stuben on 2014-11-18, 07:14:51 (66.117.237.162)
Although I have trouble with the concept that music qualities (not distortions) are influenced by the way electrons bounce around. I keep my mind open :>) There is something to be said for the manipul .......
242: Tubes Asylum, RE: Don't tube nerds care about measurments? (0.00)
Posted by Stuben on 2014-11-14, 10:49:15 (66.117.237.162)
Useless measurements of THD practically destroyed the audio business. The ears measure the quality of a system as a whole... With that said, I would normally avoid building something that I know wil .......
243: SET Asylum, RE: Difference between EL-34 & 300B sound in SE circuit (0.00)
Posted by Stuben on 2014-11-13, 06:47:59 (66.117.237.162)
Triode strapped, local OPT and global feedback... What a piece of work. Has anyone heard this 813 amp? Stuben .......
244: SET Asylum, RE: Difference between EL-34 & 300B sound in SE circuit (0.00)
Posted by Stuben on 2014-11-13, 05:30:51 (66.117.237.162)
Do ya think we're going to change these guys minds? Hell, I was just trying to change the subject ;>) I wish we all had the opportunity to have a listening session with all of the builds and systems e .......
245: SET Asylum, RE: Difference between EL-34 & 300B sound in SE circuit (0.00)
Posted by Stuben on 2014-11-12, 15:53:13 (184.57.250.166)
I think the discussion is how to create that tight string, especially the power supply. This is the fun... Stuben .......
246: SET Asylum, RE: Difference between EL-34 & 300B sound in SE circuit (0.00)
Posted by Stuben on 2014-11-12, 14:48:19 (184.57.250.166)
Tre, I have always imagined a power supply / amplifier providing a "Tightly pulled string" in between two tin cans. Stuben .......
247: Tube DIY Asylum, RE: Something I don't Understand... (0.00)
Posted by Stuben on 2014-11-12, 12:52:59 (66.117.237.162)
http://www.dmitrynizh.com/hum-moondog.htm Another site.... Stuben .......
248: Tube DIY Asylum, RE: Something I don't Understand... (0.00)
Posted by Stuben on 2014-11-12, 12:44:06 (66.117.237.162)
I have always belong to this school of Filament hum... 120 HZ hum is induced by the heating and cooling of the filament heated with a 60 HZ supply...Twisting your feeds will help prevent induced curre .......
249: SET Asylum, RE: Difference between EL-34 & 300B sound in SE circuit (0.00)
Posted by Stuben on 2014-11-12, 11:44:23 (66.117.237.162)
If you have the right speakers, my ears tell me the the EL84 sounds better triode strapped than the EL34....just an observation. I find the EL34 to sound better as it is intended as a Pentode in push .......
250: Tube DIY Asylum, RE: I just love those 45's.... (0.00)
Posted by Stuben on 2014-11-09, 05:31:21 (184.57.250.166)
Will, What speakers are you driving with those beautiful creations?? I want to build with the 45, just lacking the sensitivity in my system to get the magic out... Very Nice Stuben .......
251: Tube DIY Asylum, RE: Cathode resistor for 417A (0.00)
Posted by Stuben on 2014-11-09, 05:28:11 (184.57.250.166)
My last build with 5842s driving the primaries of LL1692s, I ended up with a 80 ohm cathode to ground. Like everything else, many variables lead you to your desired value.... I'm putting around 20 Ma .......
252: SET Asylum, RE: Can sound cleaner but loses the magic midrange. (0.00)
Posted by Stuben on 2014-11-06, 14:05:08 (184.57.250.166)
Andy, I built a Pentode SE input PP out IT topology. The ITs were Lundahl 1660s. I think the sound does maintain SE feel, the mid range is rich, with the nice tighter PP bass. I did run the OPT sectio .......
253: SET Asylum, RE: The rise time is - One Day.......... Gusser (0.00)
Posted by Stuben on 2014-11-05, 09:13:54 (66.117.237.162)
The use of CCS with a LTP configuration has been documented as an improvement for quiet some time. If you don't want to use CCS for what ever reason...don't... Have fun Stuben .......
254: Tube DIY Asylum, RE: Six years of DIY (0.00)
Posted by Stuben on 2014-10-18, 12:51:38 (24.209.237.131)
Cool builds.. OTL builds? Stuben .......
255: Tube DIY Asylum, RE: Frankenstein is ALIVE !!! Voltages all fine ..... (0.00)
Posted by Stuben on 2014-10-18, 06:07:21 (24.209.237.131)
Jeff, Nice looking work.. Give us listening impressions when ready :) BTW. I have had a bad experience with compression fittings on grounding schemes. Looks like you filled them with solder...I mitiga .......
256: Tube DIY Asylum, RE: Schottky FW bridge rectifier (0.00)
Posted by Stuben on 2014-10-06, 09:45:47 (66.117.237.162)
I also took this approach with a small board... Worked great for a DC filament supply. Stuben .......
257: Tube DIY Asylum, RE: Suppressor grid voltage and zener diodes (0.00)
Posted by Stuben on 2014-09-30, 14:56:19 (24.209.237.131)
Oh yea.. A good bypass cap on G2....PIO has been my choice. Stuben .......
258: Tube DIY Asylum, RE: Suppressor grid voltage and zener diodes (0.00)
Posted by Stuben on 2014-09-30, 14:55:04 (24.209.237.131)
Hey DAK.. I can give up a run down of my experience. We're looking for solid voltage. Short of a full-blown regulation circuit (I haven't tried yet),I have had good results using a basic voltage divi .......
259: SET Asylum, RE: curious (0.00)
Posted by Stuben on 2014-09-22, 16:07:26 (24.209.237.131)
I've Always associated VRs with having inductive qualities.. A cheap choke with the paralleled resistance... Stuben .......
260: Tube DIY Asylum, RE: Cathode Follower Output (0.00)
Posted by Stuben on 2014-09-22, 12:12:20 (66.117.237.162)
The change that kept me going was the grid chokes for the voltage amp sections. This made the drive easier....I'll take measurements after I fire up the latest version. Been fun...If I'm not satisfied .......
261: Tube DIY Asylum, RE: Cathode Follower Output (0.00)
Posted by Stuben on 2014-09-21, 13:09:52 (24.209.237.131)
Al, I need to clarify...PS calcs, valve bias and normal operating parameters were not established by ear... The topology was... Stuben .......
262: Tube DIY Asylum, RE: Cathode Follower Output (0.00)
Posted by Stuben on 2014-09-21, 13:06:21 (24.209.237.131)
Al, Not there yet. Built the prototype totally by ear. This is my rabbit hole. I'll keep you posted...I could have ignored all of the Tubecad articles and not had this much fun...as I refined the volt .......
263: Tube DIY Asylum, RE: Cathode Follower Output (0.00)
Posted by Stuben on 2014-09-18, 12:12:49 (66.117.237.162)
My CF build uses LC coupling with a nice grid choke employed on each output. I have it on the bench...just need to complete. I got some promising results from the prototype. I loaded both sections .......
264: SET Asylum, RE: DHT filament voltage (0.00)
Posted by Stuben on 2014-09-18, 05:46:39 (66.117.237.162)
Although you will probably get a few varying opinions on this subject, there are folks out there starving their filaments. http://diyaudioprojects.com/mirror/members.aol.com/sbench102/dht.html I'm su .......
265: SET Asylum, RE: awareness increase (0.00)
Posted by Stuben on 2014-09-13, 13:43:12 (24.209.237.131)
Jeff, You have cut the chassis.. so how about PP-6BX7.. Have a look at the data sheet... Been interested in this puppy for while... Stuben .......
266: Tube DIY Asylum, RE: RE 6BX7 as a driver (0.00)
Posted by Stuben on 2014-09-02, 10:50:48 (66.117.237.162)
Yep, it appears you could use the 6BL7 as a driver with a MU of 15, you'll need gain ahead of the driver in another stage or in the form of a line stage preamp. If you want to go SE on the IT primarie .......
267: Tube DIY Asylum, RE: Interesting discussion of amplifier power and listening, Steve Deckert (0.00)
Posted by Stuben on 2014-09-01, 12:07:39 (24.209.237.131)
Deckert's gear and his website was inspiration get me started designing and building. I jumped from Decware to Harvey Rosenburg's site (postmortem)....for a few years... Stuben .......
268: Tube DIY Asylum, RE: Do i need to modify this driver circuit for PSE KT88 (0.00)
Posted by Stuben on 2014-08-28, 11:08:20 (66.117.237.162)
Here's a PP application.. http://www.kandkaudio.com/images/pentodekt88amp.pdf I so far have only implemented SE on the primaries. I built an EL84 PP amp using the LL1660S (SE/PP) primaries gaped for 1 .......
269: Tube DIY Asylum, RE: Do i need to modify this driver circuit for PSE KT88 (0.00)
Posted by Stuben on 2014-08-28, 09:58:03 (66.117.237.162)
DAK, The 6BX7-GT is a high transconductance, high plate current twin triode in an octal format....used as an IT driver, would be perfect...I have one but have not yet used it... FYI Have fun Stuben :: .......
270: Tube DIY Asylum, RE: Do i need to modify this driver circuit for PSE KT88 (0.00)
Posted by Stuben on 2014-08-27, 11:58:11 (66.117.237.162)
DAK, Keep the 6SL7 as input and go with a 5687, ECC99 or 6H30PI (or similar) as a driver for the IT. The 6SN7 is a great tube, but...the above will be easier to implement as a IT driver. Did you get .......
271: Tube DIY Asylum, RE: Looking for a particular 211 schematic.... (0.00)
Posted by Stuben on 2014-08-24, 13:30:30 (24.209.237.131)
Good call...just be safe. I basically took that tack early and with me education back ground, I was able to assess my mistakes (many, luckily small..mostly) and really have fun with it...I'm feeling t .......
272: Tube DIY Asylum, RE: Are my ITs ok for this schematic? (0.00)
Posted by Stuben on 2014-08-22, 06:59:32 (66.117.237.162)
Hey DAK, A 6SL7 in front of an LL1660 IT does not sound right considering the 6SL7 plate resistance and typical plate current. Make sure you fully vet this application out before you drop $300.00 or s .......
273: Tube DIY Asylum, RE: Electronic SAFETY when Building, any GUIDE ARTICLES ? (0.00)
Posted by Stuben on 2014-08-18, 12:49:55 (66.117.237.162)
Jeff, Here's an example I found a while back... http://tubelab.com/safety/electrical-safety/ Respect coupled with knowledge...I've been lucky on a couple of occasions. Stuben .......
274: Tube DIY Asylum, RE: RH84 OT - Not from memory (0.00)
Posted by Stuben on 2014-08-08, 07:48:54 (66.117.237.162)
I'm seeing partial feedback....from plate to plate Not so straight forward... http://www.tubecad.com/march2001/ Stuben .......
275: Tube DIY Asylum, RE: I think I'm over active line stages (0.00)
Posted by Stuben on 2014-08-03, 07:19:31 (24.209.237.131)
I'm in the same camp as twystd...I have a PAS-2 that mates well with my own builds. Many variables... I have built several low gain line stages with good results. A Preamp with a simple tone control a .......
276: Tube DIY Asylum, RE: Cathode bypass capacitor (0.00)
Posted by Stuben on 2014-07-30, 08:57:00 (66.117.237.162)
Hey Tubenstein, Simply stated.. Bypassing is a fence walk between the valves distortion levels it's ability to drive the next stage. Bypass and increase drive, decrease Cathode feedback which increase .......
277: Tube DIY Asylum, RE: Summertime Blahs (0.00)
Posted by Stuben on 2014-07-21, 10:25:44 (66.117.237.162)
My post was a bit broken ..."the chokes resistance to current change" should be related to the chokes ability to filter AC through the production of CEMF and the "Surge" comment really describes the c .......
278: Tube DIY Asylum, RE: Summertime Blahs (0.00)
Posted by Stuben on 2014-07-20, 13:45:22 (24.209.237.131)
Jeff, Thanks, I'm the lazy one...I have neglected to run the latest PS arrangement.... Will consider... I have always considered transient pulls of current due to frequency induced load chances, and h .......
279: Tube DIY Asylum, RE: Summertime Blahs (0.00)
Posted by Stuben on 2014-07-20, 13:25:30 (24.209.237.131)
Totally agree concerning DHT performance compared to tricking Pentodes into somewhat DHT performance...My listening amp will probably always be a DHT amp. Getting different sounds from Pentodes howeve .......
280: Tube DIY Asylum, RE: Summertime Blahs (0.00)
Posted by Stuben on 2014-07-20, 05:57:59 (24.209.237.131)
I've been working to get this puppy in a proper chassis for a while...busted up my shoulder and all effort has stalled. The prototype achieved some pleasant results after much tweeking... Went down .......
281: Tube DIY Asylum, RE: Hearing Loss (0.00)
Posted by Stuben on 2014-07-19, 09:36:42 (24.209.237.131)
If you tolerate the buzz, a few hefty doses of sudafed over a couple of days...drink a bunch of water...should dry ya out some...I'd try that before bumping the ole immune system with a roid...althoug .......
282: Tube DIY Asylum, RE: Lost a 50 the other night (0.00)
Posted by Stuben on 2014-07-12, 06:50:36 (24.209.237.131)
Thanks guys, Emission Labs will be an option in the future...I still have 2 functional 50s..I'll try the old stock market for a backup for now. I have several amps that I alternate so no worries yet.. .......
283: Tube DIY Asylum, Lost a 50 the other night (0.00)
Posted by Stuben on 2014-07-11, 07:49:16 (66.117.237.162)
I'm mourning the loss of one of my 50s...really hurt when I considered how much it will cost to replace... Can anyone suggest a new stock option?? Might just bit the bullet and pick up 2 new ones.... .......
284: Tube DIY Asylum, RE: Thank you for all the support. (0.00)
Posted by Stuben on 2014-07-11, 07:44:17 (66.117.237.162)
Mike, Good to hear ya on the mend....surgery can be nasty...had surgery on my shoulder 6 weeks ago as a result of trying to catch a badly thrown Frisbee. Luckily no infection...but I can't lift my amp .......
285: Tube DIY Asylum, RE: Doubt about tube rectifiers (0.00)
Posted by Stuben on 2014-07-02, 09:26:49 (66.117.237.162)
Aldovan, I tend to use the rectifier with the least amount of voltage drop. The 5Y3 IMHO is better suited for a guitar amp where the drop can be appreciated. 5AR4/GZ34 all the way....buy a NOS Mullar .......
286: Tube DIY Asylum, RE: good, cheap, parafeed headphone transformers (0.00)
Posted by Stuben on 2014-06-17, 09:03:03 (66.117.237.162)
I used a couple of Lundahl LL1674 wired in reverse for my 5687 Parafeed line stage...great results...if you configure the secondaries right, the output impedance will run around 200 ohm.... The LL1674 .......
287: Tube DIY Asylum, RE: Dayton was kind of a bummer...... (0.00)
Posted by Stuben on 2014-05-21, 08:00:34 (66.117.237.162)
Crap I missed the meet again...I live right the road and the schedule always eludes me.... Stuben .......
288: Tubes Asylum, RE: Exactly. (0.00)
Posted by Stuben on 2014-05-16, 03:58:11 (66.117.237.162)
I also found some sweet Mullard ECC88s in an old scope a friend gave me for parts... Very Nice Stuben .......
289: Tube DIY Asylum, RE: here is a mod for you guys and it works well and I use it on (0.00)
Posted by Stuben on 2014-05-15, 12:53:25 (66.117.237.162)
Mike, It would interesting to measure the resistance between your "Audio" grounds and your mains bonding bar. If you had a ground fault in your audio gear and you had a sizable differential, the entir .......
290: Tube DIY Asylum, RE: here is a mod for you guys and it works well and I use it on (0.00)
Posted by Stuben on 2014-05-14, 05:00:43 (66.117.237.162)
or are you totally separating your ground as a way to isolate from the noisy house ground?? We do this with automation systems...it use to drive the inspectors nuts... Stuben .......
291: Tube DIY Asylum, RE: here is a mod for you guys and it works well and I use it on (0.00)
Posted by Stuben on 2014-05-14, 04:40:04 (66.117.237.162)
Mike, I'm assuming that the "Grounded" neutrals are still bonded to your service earth ground bar. How are using the additional ground? Stuben .......
292: Tube DIY Asylum, RE: G2 supply , what is the best sounding design? (0.00)
Posted by Stuben on 2014-05-13, 08:47:53 (66.117.237.162)
Maybe a CCS for shunt regulation...I did try a CCS and a VR tube once in series with G2....on a class A output....sound was much better with a couple of resisters in a shunt regulation scheme... Stube .......
293: Tube DIY Asylum, RE: The Best? (0.00)
Posted by Stuben on 2014-05-12, 09:42:21 (66.117.237.162)
I have found a basic shunt regulation scheme sounds better than a CCS to my ears....best doesn't mean much if you don't have the real estate... Stuben .......
294: Tube DIY Asylum, RE: G2 supply , what is the best sounding design? (0.00)
Posted by Stuben on 2014-05-12, 08:09:01 (66.117.237.162)
If you have the space, a separate solid PS is the way. I have found good results by employing a voltage divider with a shunt to ground where space is a premium. Stuben .......
295: Tube DIY Asylum, RE: hook up wiring (0.00)
Posted by Stuben on 2014-05-08, 12:43:21 (66.117.237.162)
I have Belden shielded pair cable for heater distribution. Landing the shield to earth. Cuts down heater noise induced into surrounding conductors. Stuben .......
296: Tube DIY Asylum, RE: Please help with Parafeed Cap value (0.00)
Posted by Stuben on 2014-04-30, 14:37:19 (24.209.237.131)
Buy ya some Solen Tin foils of different values in the range that you're playing with....if you feel the need to experiment with the lower end...Calcs get you in the ball park as far as the ear is con .......
297: SET Asylum, RE: Pedantic note (0.00)
Posted by Stuben on 2014-04-26, 05:35:39 (24.209.237.131)
Paul, Thanks for the clarity...I had the hear the term used prior for valves with out the internal connection. Stuben .......
298: SET Asylum, RE: EL84 and true pentodes interesting question (0.00)
Posted by Stuben on 2014-04-24, 18:16:05 (24.209.237.131)
Sorry...Cathode to G3...typo .......
299: SET Asylum, RE: Why would you tie G1 & G3 together at the socket........ (0.00)
Posted by Stuben on 2014-04-24, 18:15:08 (24.209.237.131)
Yep I tie the cathode to G3. Stuben .......
300: SET Asylum, RE: Mortgage my house? I know you're speaking figuratively, but all these alternatives... (0.00)
Posted by Stuben on 2014-04-24, 14:37:42 (24.209.237.131)
$265.00 for those puppies is pretty good. I have used the black Solens for PS smoothing...I can't say that I have ever regretted it....as a Parafeed or coupling cap, no way.... done that. No compariso .......
301: SET Asylum, EL84 and true pentodes interesting question (0.00)
Posted by Stuben on 2014-04-24, 12:58:31 (66.117.237.162)
Guys, I have noticed something interesting about the use of EL84s and a Russian variant that I'm using that is a true pentode (no internal cathode to grid 3 connection). I have my sockets connected to .......
302: SET Asylum, RE: A final (I hope) question about main-PS (600VDC) caps for my Frankensteins (0.00)
Posted by Stuben on 2014-04-23, 09:04:18 (66.117.237.162)
I'm seeing a sand bridge rectifier and a 5u4 followed by a choke that is only good for 100 mA. With the bleed on the end, that choke has to be pushing 90% current capacity for 10H. Before I mortgage .......
303: SET Asylum, RE: VT 52 tube (0.00)
Posted by Stuben on 2014-04-06, 14:13:06 (24.209.237.131)
I have 3 Sylvania VT-52s. It appears from the data available, they have the same operating points as the 45. From what I have read, the Western Electric VT-52 can be run harder. Jeff, What is your ex .......
304: Tube DIY Asylum, RE: Place to get long thread RCA's (0.00)
Posted by Stuben on 2014-04-06, 13:35:15 (24.209.237.131)
I have used these for thick stuff. http://www.partsconnexion.com/prod_pdf/cardas_62015.pdf Stuben .......
305: Tube DIY Asylum, RE: Questions regarding similar transformer coupled circuits (0.00)
Posted by Stuben on 2014-04-06, 07:12:48 (24.209.237.131)
I'd look at the LL1692,they should yield more inductance with your application. I used these on my 50 monos...I found the LL1692As better matched for the application. You will probably get different r .......
306: Tube DIY Asylum, RE: Questions regarding similar transformer coupled circuits (0.00)
Posted by Stuben on 2014-04-05, 13:17:12 (24.209.237.131)
wpod, I built a variation using 6c45Pi driving LL1660SPP..primaries in series. PPP EL84, cathode feedback (only feedback) with LL1682PP OPT secondaries... Pentode connected the sound is big open sound .......
307: SET Asylum, RE: two questions about 45 and 300b..............thanks (0.00)
Posted by Stuben on 2014-04-03, 14:36:27 (24.209.237.131)
Hey Bouncy, You could look at the 50. Old stock valves are rare and silly expensive. I believe that there is at least one maker out there that is making new 50s. I have really enjoyed the sound of the .......
308: Tube DIY Asylum, RE: High transconductance tubes sound as transistors... (0.00)
Posted by Stuben on 2014-03-29, 07:01:12 (24.209.237.131)
I use the 5687 & the 5842. I've never made this observation. I would think the sound would totally rely on the design. Stuben .......
309: SET Asylum, RE: Sound quality of modern motor-run caps in tubed powersupplies? (0.00)
Posted by Stuben on 2014-03-22, 07:55:09 (24.209.237.131)
Well if really need to tinker. The difference in sound will not be worth the effort. If you need sling solder over listening have at it...and be careful while commissioning. It's not likely, you will .......
310: Tube DIY Asylum, RE: Is anyone going the Dayton Hamfest this May? (0.00)
Posted by Stuben on 2014-03-20, 14:57:27 (24.209.237.131)
I'll be there if possible...my only off-spring is graduating sometime in May don't have my act together yet. just a few miles down the road though.. Stuben .......
311: SET Asylum, RE: Amp repair (0.00)
Posted by Stuben on 2014-02-25, 14:19:36 (24.209.237.131)
You have a great resource close by...you're lucky Mike, I think,is in the Saginaw area...if you find yourself in dire need, I'm north of Cincinnati... Stuben .......
312: Tube DIY Asylum, RE: solid-state diodes added to GZ34/5AR4 (0.00)
Posted by Stuben on 2014-02-23, 06:56:56 (24.209.237.131)
Is this some weird test? .......
313: Tube DIY Asylum, RE: Naive Question (0.00)
Posted by Stuben on 2014-02-14, 13:14:20 (24.209.237.131)
So what is your plan for upgrading the caps? Stuben .......
314: Tube DIY Asylum, RE: Need some advise on power supply design (0.00)
Posted by Stuben on 2014-02-14, 11:52:52 (24.209.237.131)
If memory serves me, the Choke input will take about 10% of the B+...if you start with 360V of pulse DC, you're going to be in the ball park.. You always want to come in a little low then tweak with a .......
315: SET Asylum, RE: 'Scuse me, while I shoot myself ;-} (0.00)
Posted by Stuben on 2014-02-13, 15:38:41 (24.209.237.131)
I understand the rant but....everyone who really loves the sound of reproduced music has their own idea and taste of what sounds good to them. Not everyone can afford an SET that can drive the average .......
316: Tubes Asylum, RE: Psvane Tubes better than NOS?!? (0.00)
Posted by Stuben on 2014-01-29, 09:26:37 (66.117.237.162)
I picked up a pair of HiFi 6CA7s...thought they sounded good until I rolled a pair of new stock Mullards. I was truly surprised at the difference....so I picked up a pair of used old stock Mullard EL3 .......
317: Tube DIY Asylum, RE: Another amplifier I built had none (0.00)
Posted by Stuben on 2014-01-28, 14:27:58 (24.209.237.131)
From what I a have read and experience, oscillation and grid blocking are the 2 issues a grid stop is used to avoid. In case of grid blocking (from what I have read) the grid stop is used when global .......
318: Tube DIY Asylum, RE: Input 1K resistors - which is best? (0.00)
Posted by Stuben on 2014-01-26, 16:31:34 (24.209.237.131)
Hell I don't use a grid stop unless I know the valve will oscillate or I have an oscillation issue...for instance, for a hot rod transconductance like a 5842/417a (they were designed to oscillate) , y .......
319: Tube DIY Asylum, RE: Pentode "Red Plate" (0.00)
Posted by Stuben on 2014-01-24, 12:25:53 (24.209.237.131)
When the loading resister (grid to ground) fails in an open circuit...the tube goes wide open....I have experienced this before.... Stuben .......
320: Tube DIY Asylum, RE: Static Electricity ??? (0.00)
Posted by Stuben on 2014-01-24, 12:20:54 (24.209.237.131)
I isolated my volume pot knob because of the pop I got every time I got up from my listening chair which is cheap leather to adjust the volume....it is a consideration...static is everywhere when the .......
321: SET Asylum, RE: One 200W SET Monoblock Complete, One to Go (0.00)
Posted by Stuben on 2014-01-16, 14:23:31 (24.209.237.131)
Very Nice work... Pleeeese be extra careful working with that potential. Sound?? Stuben .......
322: SET Asylum, RE: Compared to what? (0.00)
Posted by Stuben on 2013-12-30, 14:45:46 (24.209.237.131)
Although size does somewhat matter, too large brings different challenges. Typically, global feedback is employed to cover an inadequate OPT. Like all things in design, the big picture has to be exam .......
323: SET Asylum, RE: SET integrated amps with either phono or dac (0.00)
Posted by Stuben on 2013-12-13, 14:11:23 (24.209.237.131)
I've been thinking about building a SEP EL84 RC coupled with the EF86 triode strapped as a voltage amp... not sure if Mullard strapped it as a triode..need to have a look.. Stuben .......
324: SET Asylum, RE: SET integrated amps with either phono or dac (0.00)
Posted by Stuben on 2013-12-10, 14:19:22 (24.209.237.131)
Quad has an integrated version of the Quad II with a phono stage, on the market....not SET but pretty good approach to the Tetrode world...it looks like they have moved away from the EF86 to ECC88s an .......
325: Tube DIY Asylum, RE: Just Started on my PS1 power supply from GlassWare (0.00)
Posted by Stuben on 2013-12-09, 16:02:52 (24.209.237.131)
I've used the Hammond offering...I've had some not so quiet characters in the past but generally not a bad product... I have always used Lundahl products for my signal stuff (under the chassis)...they .......
326: Tube DIY Asylum, RE: My latest amplifier build: Multi-Valve (0.00)
Posted by Stuben on 2013-12-01, 05:19:33 (24.209.237.131)
Very Nice work. I like the sound of the SE Pentode when tamed a bit. Nice looking lay out... Stuben .......
327: Tube DIY Asylum, RE: Stuben... (0.00)
Posted by Stuben on 2013-11-29, 12:01:53 (24.209.237.131)
Funny you mention that...I have three cats...they don't seem interested but I never leave them in the room a loan when I listen to this amp. I can't seem to finish the chassis ...hopefully soon. Stube .......
328: Tube DIY Asylum, RE: The usefulness of Cathode Followers. (0.00)
Posted by Stuben on 2013-11-26, 15:59:38 (24.209.237.131)
Dave, I built a version of Olsher's Blue Velvet line stage with a plate follower config. Nice results...so far a CF voltage amp I've tried doesn't quite get there....I ran A DIY 5687 CF for a while .......
329: Tube DIY Asylum, RE: I got that USB DAC coming. (0.00)
Posted by Stuben on 2013-11-26, 15:18:27 (24.209.237.131)
Mike, I have a couple of DACs from China. Both non oversampling. Basically, these cats put 8 vintage DAC chips in parallel. In both cases, the providers were active in forums and listened to feedback .......
330: Tube DIY Asylum, RE: Question about a resistor on negative feedback circuit (0.00)
Posted by Stuben on 2013-11-25, 15:49:40 (24.209.237.131)
Waterman, In the spirit of DIY, can the entire feedback loop. Ground the cathodes of your output section through the secondaries of you OPT. Be sure to include a bias resister in series. Connect Ultra .......
331: Tube DIY Asylum, RE: SE 45's in stereo : tube ghetto... (0.00)
Posted by Stuben on 2013-11-24, 15:18:10 (24.209.237.131)
Here's a Pentode example... Stuben .......
332: Tube DIY Asylum, RE: Dude that's Jackson Pollock's build (0.00)
Posted by Stuben on 2013-11-23, 11:08:28 (24.209.237.131)
Does kinda have a 3D flavor if you stare at it long enough... This builder might have been in the same state of mind as ole Jackson while slinging solder. Blind drunk... Stuben .......
333: Tube DIY Asylum, RE: I put a choke in my Eico HF22, then loud hum coming from the speaker (0.00)
Posted by Stuben on 2013-11-23, 11:03:41 (24.209.237.131)
cktc, There's a strong chance the current passing through your 1.5 H choke is not enough to keep the choke input at critical inductance or above. Not doing so can make a choke input a bad solution for .......
334: Tube DIY Asylum, RE: Omitting Attenuator (0.00)
Posted by Stuben on 2013-11-22, 09:27:21 (66.117.237.162)
Anthony, The resister to ground controls how much your grid goes negative which controls how much your tube conducts. If you omit this resister, your preamp tube will go wide open as far as current, w .......
335: Tube DIY Asylum, RE: Has anyone hooked their computer up to a tube amp or amps for general listening? (0.00)
Posted by Stuben on 2013-11-16, 05:11:00 (24.209.237.131)
Mike, I use a USB capable DAC from time to time to listen to music files and Internet Radio...not bad...it's all in how good your DAC does it's job. Stuben .......
336: Tube DIY Asylum, RE: Parts Connexion or Tube Store (0.00)
Posted by Stuben on 2013-10-30, 06:46:43 (66.117.237.162)
Hey bajaed, I have bought a load of stuff from Parts Connexion ..never had any issues. I don't like their NOS selection of tubes...no issues getting from Canada to US...I see you're from KY...I'm in t .......
337: SET Asylum, RE: Ground Loops and Isolation Transformers....................... (0.00)
Posted by Stuben on 2013-10-14, 15:26:08 (65.189.32.24)
lol...you're right about risks...getting out of bed will kill ya... Yea the GFI (when working properly) will drop the circuit out...as apposed to a hardwired solution :> Been building for years..never .......
338: SET Asylum, RE: Ground Loops and Isolation Transformers....................... (0.00)
Posted by Stuben on 2013-10-14, 14:48:19 (65.189.32.24)
Hey Cut Throat, So just for my understanding, you have a sound grounding system in your dwelling (House,APT,Condo,grass hut)...? Or you know ya have a bad grounding system and there is no practical wa .......
339: Tube DIY Asylum, RE: Direct Coupled E-Linear Amp (0.00)
Posted by Stuben on 2013-10-11, 14:15:28 (65.189.32.24)
Vinnie, Paul's suggestion will cover your PS transformer issue...very nice. The schematic is a little fancy for a neophyte builder but you can use that 400 to 400 transformer... By raising the EL84 ca .......
340: SET Asylum, RE: looking for help with a PSU (0.00)
Posted by Stuben on 2013-10-10, 08:55:00 (66.117.237.162)
Vinnie, This is a common DIY problem. I would suggest getting another power tranny. Anything you do to drop the voltage will basically work against a good result. A choke input will only take about 1 .......
341: SET Asylum, RE: I found the opposite (0.00)
Posted by Stuben on 2013-10-08, 16:04:20 (65.189.32.24)
Thank You .......
342: Tube DIY Asylum, RE: Tube bias (0.00)
Posted by Stuben on 2013-09-26, 09:26:49 (66.117.237.162)
You can try cathode bias (Auto)....just let those valves warm up and get old...no problem... Stuben .......
343: Tube DIY Asylum, RE: I made me kind of a quasi tertiary winding in a dynaco ST70. (0.00)
Posted by Stuben on 2013-09-26, 09:21:54 (66.117.237.162)
Mike, I you tried grounding the output cathode through the secondary of the OPT transformer....you're puttin some DC on the crossover and driver but I have not yet experienced any issues...I'm using t .......
344: Tube DIY Asylum, RE: Juicy Music Tercel phono stage. (0.00)
Posted by Stuben on 2013-09-11, 08:09:43 (66.117.237.162)
Hey Mike, A phono stage will likely be my next project...got my hands on a turn table and I'm really enjoying it even through one of my SS amps.... A schematic would be cool. A schematic of your prefe .......
345: Tube DIY Asylum, RE: This is how they will tube amps one day. (0.00)
Posted by Stuben on 2013-09-09, 14:20:02 (65.189.32.24)
It would be nice to think a market for tube amps would make such a thing plausible...I've always imagined a day when teenage kids traded tubes like marbles... If the market had somehow stayed with hig .......
346: Tube DIY Asylum, RE: This is how they will tube amps one day. (0.00)
Posted by Stuben on 2013-09-08, 13:36:14 (65.189.32.24)
It would be nice to think a market for tube amps would make such a thing plausible...I've always imagined a day when teenage kids traded tubes like marbles... If the market had somehow stayed with hig .......
347: Tube DIY Asylum, RE: Transformer blowing fuses??? (0.00)
Posted by Stuben on 2013-09-08, 13:15:51 (65.189.32.24)
yep, check your caps...unless you have done something really stupid with the trannys, which can happen when you start stuff up for the first time...I have a few personal bad stories... Stuben ::: TOP .......
348: Tube DIY Asylum, RE: Home from the first day back at the salt mines. (0.00)
Posted by Stuben on 2013-09-05, 08:37:39 (66.117.237.162)
Mike, I got admire the patience of a teacher...molding young minds... Are teaching regular HS or Vocational? I always thought it would be fun to get out of my business and work as a Voed instructor... .......
349: Tube DIY Asylum, RE: The McIntosh Unity coupled circuit. (0.00)
Posted by Stuben on 2013-08-31, 09:26:37 (65.189.32.24)
Mike, Took a look at the schematic...looks curiously similar a cathode follower OP along with similar characteristics like unity gain and low OP impedance. Yet the plates are loaded. Are the inductor .......
350: SET Asylum, RE: switches on Korneff power amp (0.00)
Posted by Stuben on 2013-08-30, 10:44:35 (65.189.32.24)
Sam, You always want a hot tube before applying the B+. So ya turn on heaters then high voltage and then reverse the sequence to turn off. It's a good practice especially with direct heated cathodes. .......
351: SET Asylum, RE: The old passive vs active controversy (0.00)
Posted by Stuben on 2013-08-29, 09:01:22 (66.117.237.162)
Aren't we talking about amps that need additional gain in front and those that don't...if you put a passive in front of an amp with sufficient gain you will probably have a better chance of a positive .......
352: Tube DIY Asylum, RE: Tube Amp Project Suggestions for a Novice? (0.00)
Posted by Stuben on 2013-08-27, 12:37:00 (66.117.237.162)
Hey Curlomatic... Find yourself an old SE power amp chassis from a late 50s, early 60s console, gut the amp and start again. For the purposes of learning, start with triode strapping just to get some .......
353: SET Asylum, RE: What is the best impedance transformer to use for a 2a3 set amp? (0.00)
Posted by Stuben on 2013-08-21, 14:40:03 (65.189.32.24)
RC How did your build sound compared to the reports... Stuben .......
354: SET Asylum, RE: SE OPT query (0.00)
Posted by Stuben on 2013-08-21, 10:36:28 (66.117.237.162)
I would think someone has already asked but... Does the cap go to ground? and/or does the tap signal continue to the up stream sections? It is either more B+ smoothing or feedback similar to UL or gl .......
355: SET Asylum, RE: Rp (0.00)
Posted by Stuben on 2013-08-20, 11:14:34 (66.117.237.162)
Good point, I'm assuming that the tube rolling doesn't include anything more than a bias adjustment. To lower 45 Rp you're going to eventually run into max dissipation. I imagine you could keep loweri .......
356: SET Asylum, RE: Question.... (0.00)
Posted by Stuben on 2013-08-15, 08:16:54 (66.117.237.162)
That's a tough question answer considering all of the unknowns.. 2a3 Rp= 800 ohm 45 Rp= 1650 ohm If you were swapping on 2a3 amp, the primaries are probably 3k. The 45 probably isn't totally on it's g .......
357: Tube DIY Asylum, RE: A common missconception ... (0.00)
Posted by Stuben on 2013-08-14, 14:56:53 (65.189.32.24)
All of my builds use a choke input until I find that it's not appropriate through measurement and listening...calcs give ya vague picture...compared to the ears. Just repeating others... When you fac .......
358: SET Asylum, RE: What is the best impedance transformer to use for a 2a3 set amp? (0.00)
Posted by Stuben on 2013-08-14, 14:42:49 (65.189.32.24)
Mike, If you're building for someone or you don't want to deal with the added expense of experimenting and letting your ears do the selecting, I'd go with the lower impedance choice.I can't claim to h .......
359: Tube DIY Asylum, RE: is certainly not a POS" Hmm, it was SO bad, the tube industry invented the 6CG7 to replace the 6SN7... (0.00)
Posted by Stuben on 2013-08-14, 09:04:21 (66.117.237.162)
Plug it in and have a listen.....as said before, the bias differences will will probably result in a bad listening experience. .......
360: Tube DIY Asylum, RE: Jerry Boncer - has anyone heard of him? ... (0.00)
Posted by Stuben on 2013-08-14, 08:35:49 (66.117.237.162)
I've read a few strings in other forums where the author has stated that a PS choke in a class A amplifier is over kill because of the class A current being inherently constant. My ears like the PS ch .......
361: Tube DIY Asylum, RE: I rebuild and service about 7 suprateks a year on average. (0.00)
Posted by Stuben on 2013-08-08, 09:32:13 (66.117.237.162)
Is there a grid resister or is he using the CCS to load the grid like a grid choke?? Stuben .......
362: SET Asylum, RE: What is the best impedance transformer to use for a 2a3 set amp? (0.00)
Posted by Stuben on 2013-08-07, 09:33:24 (66.117.237.162)
If I were going to build a 2a3 SE amp, 3k primaries would be my choice. If I were experimenting it's a different ball game. LL1664 (3k primaries) would be my pick for a build, LL1620 (3.3, 6 or 11.5 K .......
363: Tube DIY Asylum, RE: PPPUL EL84 Amp...Does one exist? (0.00)
Posted by Stuben on 2013-08-06, 10:46:13 (66.117.237.162)
Duh, I guess I should learn to read... Parallel Push Pull...I'm so accustomed to seeing triode strapped amps, I thought we were talking about Pentode PP. I have never listened to Paralleled output sta .......
364: Tube DIY Asylum, RE: PPPUL EL84 Amp...Does one exist? (0.00)
Posted by Stuben on 2013-08-05, 18:26:28 (65.189.32.24)
Here's the latest schematic. I think the ability to adjust the cathode feedback would be a good addition. .......
365: Tube DIY Asylum, RE: PPPUL EL84 Amp...Does one exist? (0.00)
Posted by Stuben on 2013-08-05, 09:55:55 (66.117.237.162)
Mike, LL1660S are used for the IT. I configured the primaries SE (all in series)to get the most H possible. Those are 47uF Solen power smoothers, 3 per channel. The OPTs are Lundahl LL1682s, this iron .......
366: Tube DIY Asylum, RE: order of filament wiring............. (0.00)
Posted by Stuben on 2013-08-05, 09:34:34 (66.117.237.162)
When supplying filament voltage in a parallel configuration, the voltage will be constant everywhere as long as you're within the capability of the supply. A star is a parallel installation. You only .......
367: Tubes Asylum, RE: Psvane 6sn7 (0.00)
Posted by Stuben on 2013-08-02, 13:45:06 (65.189.32.24)
I had a similar experience with EL34s. Listened for while thinking "These guys sound good"...rolled a couple of Mullard new stock and was taken a back by the difference. The new Mullards sounded bette .......
368: Tube DIY Asylum, RE: PPPUL EL84 Amp...Does one exist? (0.00)
Posted by Stuben on 2013-08-01, 09:47:40 (66.117.237.162)
Built such an animal, SE IT coupled input, Push Pull Pentode UL connected output. Dual Mono platform. Nice sound. Pictures taken when amp was connected in Triode. I finally figured out that Pentod .......
369: SET Asylum, RE: I want to ask you guys a serious question. (0.00)
Posted by Stuben on 2013-07-28, 13:58:28 (65.189.32.24)
Mike, Totally agree, good ears that are willing to stop by any give ya an honest opinion is truly golden. Modifications have been a result of such.. I did read an article in a UK publication where the .......
370: Tube DIY Asylum, RE: I have a lot of 5687s and I was looking over the data as a driver and to me, (0.00)
Posted by Stuben on 2013-07-24, 08:59:04 (66.117.237.162)
Mike, I built a 5687 parafeed Line Stage using the LL1674 as an OPT. The 5687 likes to run at around 20 mA. I've be quite impressed. They are known for microphonics when they get "long in the Tooth".. .......
371: Tube DIY Asylum, RE: 6CB5 : low power SE (0.00)
Posted by Stuben on 2013-07-15, 14:35:01 (65.189.32.24)
I would rather use Iron but the CCS solution has much merit. I'm loading both halves of 6SN7s with CCS to drive SECF Pentode outputs that are a challenge. Works well.Sounds amazing. The dampening is o .......
372: Tube DIY Asylum, RE: I think I found the schematic. (0.00)
Posted by Stuben on 2013-07-11, 12:07:10 (66.117.237.162)
For the 5842 I used ferrite beads on the filament conductors in addition to a grid stop on all (4) grids....No issues that I can hear. These little hot rods are wonderful voltage amps. Stuben ::: TOPI .......
373: SET Asylum, RE: Returning to SET. (0.00)
Posted by Stuben on 2013-07-04, 16:47:58 (65.189.32.24)
Practical power looks a bit over stated. Reminds me of the Quad offering which provides 18 watts with PP configured KT66 and EF86 input. Follow your ears... Stuben .......
374: Tubes Asylum, RE: Type 50 Tube (0.00)
Posted by Stuben on 2013-03-09, 15:16:25 (71.79.5.241)
JCmusic, I'm running 50 monoblocks. To me, they have similar attributes but the 50 can give you at least twice the power. Very open, glorious mid range, great sound stage with healthy thump...I unders .......
375: SET Asylum, RE: 2A3 & 6SL7 advice needed (0.00)
Posted by Stuben on 2013-02-14, 16:52:37 (12.178.24.10)
Roll in 67n7S if you have some gain in front. Stuben .......
376: Tube DIY Asylum, RE: Looking for a KT88/6550A SE project (0.00)
Posted by Stuben on 2013-01-28, 16:36:08 (71.79.5.241)
Eli, I work the cathodes with the Secondary of the Output and use UL connections on my Lundahls... Great results.. You're running your Bias voltage across your speaker terminals which feels weird but .......
377: SET Asylum, RE: Should i rectify the heater circuit in my 7591 SE stereo? (0.00)
Posted by Stuben on 2013-01-11, 15:17:59 (71.79.5.241)
Hey DAK, You can go with DC heaters, but the chances of this being your problem is low, especially with indirectly heated valves. Check your grounding, check your PS filtering. If you are hearing only .......
378: Tube DIY Asylum, RE: Who cares? I mean, really... (0.00)
Posted by Stuben on 2012-11-25, 15:35:03 (71.79.5.241)
I'm sure those who are just getting their feet wet with this stuff are reading this debate and wondering if they're at the right place.. to learn. The well has been poisoned... Stuben .......
379: Tube DIY Asylum, RE: I like cap input supplies! (except for filaments) (0.00)
Posted by Stuben on 2012-08-28, 16:12:44 (71.79.5.241)
I will typically arrange a choke input and adjust my B+ with a small value cap which makes a CLC arrangement. I agree concerning the excitement that can be added with some distortion. I run 50 triode .......
380: Tube DIY Asylum, RE: How do you test glow tubes? (0.00)
Posted by Stuben on 2012-08-27, 17:24:13 (71.79.5.241)
Andy, If your tube regulators are not striking, you have a drop in B+ Voltage which means you have some current going somewhere the circuit was not designed for, which drops B+ below the striking volt .......
381: Tube DIY Asylum, RE: Audiophiles have become more unreasonable....... (0.00)
Posted by Stuben on 2012-08-05, 15:13:31 (71.79.5.241)
Dan, I built a similar topology only using (2) halves of a 67N7...Both halves loaded with a CCS, RC coupled and standard self bias on the output. I found that Triode strapping the output provided too .......
382: Tubes Asylum, RE: Russian Reflektor 6H30P-DR Supertube? (0.00)
Posted by Stuben on 2012-07-28, 07:48:47 (71.79.5.241)
WolfBane, I drive the primaries of a set of LL1660S PP ITs with one 6H30P-DR. Does the job well. Sounds good. This valve is very much like a beefy 5687 as far as sound. No microphonics...very quiet. T .......
383: SET Asylum, RE: Taiwan is hardly third world and, e.g., Neotech is made there (0.00)
Posted by Stuben on 2012-07-25, 17:42:09 (71.79.5.241)
Guys, With all of the Aye Rand quoting, on the take Law Makers in this great nation coupled with the Fox News propaganda, we are ALREADY on the fast track to 3rd world status...the argument is basical .......
384: Tube DIY Asylum, RE: High current vs. low current drivers for direct couple 2a3 amplifiers. (0.00)
Posted by Stuben on 2012-07-11, 16:03:41 (71.79.5.241)
This is no reason for the current agreed... There is some glorious sound made by low/mid MU higher current drivers applied in transformer coupling...a different world. IMHO...A better higher mu driver .......
385: Tube DIY Asylum, RE: figure out what the proper sized transformer would be and buy it (0.00)
Posted by Stuben on 2012-07-07, 07:11:49 (71.79.5.241)
Agreed...anything else you do will probably be heard... Stuben .......
386: SET Asylum, RE: The road ahead (0.00)
Posted by Stuben on 2012-06-26, 15:55:51 (65.189.34.82)
Tube, That must have been some good stuff;>) Your writing is too nice to trivialize with debate. If everyone uses their ears and leverage science to that end...no issues.. Oh...was that an opinion? St .......
387: Tube DIY Asylum, RE: Ok...I acknowledge we are ALL no so afraid of Pentodes anymore... (0.00)
Posted by Stuben on 2012-06-04, 16:04:01 (65.189.34.82)
I have a real love for a nicely tamed Pentode. Attached is a pic of my latest prototype....CFSE34... I'm loading two halves of 6SN7 with CCS per channel. The screen grids fed by a basic voltage div .......
388: Tube DIY Asylum, RE: Back to basics (0.00)
Posted by Stuben on 2012-06-01, 13:45:38 (65.189.34.82)
If you're loading with the CCS OK, what is the input impedance that you're trying to match ?...the LL1660 secondaries need to accommodate. I like your approach...in think:>). At first look, I would be .......
389: Tube DIY Asylum, RE: Choke input filter - 1 rectifier into 2 chokes (0.00)
Posted by Stuben on 2012-05-24, 05:14:26 (66.117.237.162)
Sushii, I'm not sure how the rectifier will see the loads. Looks a bit dubious in that the Rectifier could be seeing two loads in parallel. If you're really concerned with separation, go with (2) rect .......
390: Tube DIY Asylum, RE: Mechanical Diodes (0.00)
Posted by Stuben on 2012-05-23, 17:30:14 (65.189.34.82)
Henry, Here's a closer look at the CFSE EL34 prototype. I'm loading both halves of the 6sn7 with a CCS. The power supply is solid. The screen supply of the EL34 is using a basic voltage divider/ sh .......
391: Tube DIY Asylum, RE: I am so careless and stupid......... (0.00)
Posted by Stuben on 2012-05-23, 15:44:51 (65.189.34.82)
Dude, we all screw up from time to time...if you don't, you're not doing anything. I once connected a VT52 UP BACKWARDS and then only realized it when the $40.00 cathode bypass cap started popping... .......
392: Tube DIY Asylum, RE: Thanks for sharing.... (0.00)
Posted by Stuben on 2012-05-22, 12:23:53 (66.117.237.162)
Hey Gordon, This is something I once screwed up and I was surprised by the improvement when corrected. Make sure that your central ground (star)is landed at the furthest point from the B+ user which w .......
393: SET Asylum, RE: Silk's 10W/ch EL-34 UL Pentode "Minute" amp from DIY Hi-Fi Supply (0.00)
Posted by Stuben on 2012-05-22, 11:43:47 (66.117.237.162)
Sounds like a nice amp...need to look it up:>) Stuben .......
394: SET Asylum, RE: Looking for first (inexpensive) SET (0.00)
Posted by Stuben on 2012-05-21, 15:39:49 (65.189.34.82)
Decware Bottlehead They're all good products. I built a strapped EL84 amp similar to the Decware product (inspired by) Sounds good, much better power supply than the Decware offering . If you have the .......
395: Tube DIY Asylum, RE: Want to build a MC head amp -- simple design (0.00)
Posted by Stuben on 2012-05-20, 09:16:11 (65.189.34.82)
Hey Jedrider, What Eli said... http://www.kandkaudio.com/phonostage.html just a thought:) Stuben .......
396: Tube DIY Asylum, RE: Mechanical Diodes (0.00)
Posted by Stuben on 2012-05-19, 14:21:39 (65.189.34.82)
Henry, Cool, most of my pics are of earlier versions of my amps...Maybe I should send them and explain what has changed. I have a CF SE EL34 amp that is still on a piece of plywood...It was inspired .......
397: Tube DIY Asylum, RE: projects for dynaco iron/ (0.00)
Posted by Stuben on 2012-05-19, 06:40:59 (65.189.34.82)
I have a couple PA-060 power transformers. I was going to use one of them for my CF SE EL-34 project. I have never used one so I'm banking that it will make a decent power tranny for a Stuben ::: TO .......
398: Tubes Asylum, RE: Tube Preamps That Don't Hum - Any Such Thing? (0.00)
Posted by Stuben on 2012-05-18, 17:30:44 (65.189.34.82)
Mike, How old is your House or apartment? Check to make sure that your grounded neutral and Hot conductors are in the proper position (polarity). Does your place use a (2) conductor with a ground sche .......
399: Tube DIY Asylum, RE: K&K is now offering a VFD kit for turntables (0.00)
Posted by Stuben on 2012-05-18, 16:47:30 (65.189.34.82)
ecir38, It's at the home page. http://www.kandkaudio.com/index.html I have no experience with this new product. I have however had good experiences dealing with Mr. Carter. Take Care Stuben ::: TOPIC: .......
400: SET Asylum, RE: Thanks. I'll wait for the files NT (0.00)
Posted by Stuben on 2012-05-18, 14:41:06 (65.189.34.82)
Sidewinder, I've tweeked this schematic several times. The regulator on C+ especially. The LL1692 wire with all of the primaries in series and the secondaries in series. Have fun Stuben ::: TOPIC:: .......
401: Tube DIY Asylum, RE: Anything to be gained or loss by two chokes in series vs. one in PS? (0.00)
Posted by Stuben on 2012-05-16, 14:55:28 (65.189.34.82)
Paully, If you're working with a voltage amp...probably not a big deal either way. If you talking about a choke input for a power amp, you want to keep the impedance as low as reasonable and that much .......
402: Tube DIY Asylum, RE: The age of GREED us upon us, big time! nt (0.00)
Posted by Stuben on 2012-05-16, 14:44:36 (65.189.34.82)
Guys, I apologize for the last post...this is not the place. Stuben .......
403: Tube DIY Asylum, RE: The age of GREED us upon us, big time! nt (0.00)
Posted by Stuben on 2012-05-16, 13:36:22 (66.117.237.162)
I acknowledge that this isn't the forum for this but, there's the school of thought that every man is an island that has gained an alarming amount of momentum in recent years. I know that this school .......
404: Tube DIY Asylum, RE: Question (0.00)
Posted by Stuben on 2012-05-16, 07:08:29 (66.117.237.162)
I agree that the EL84 can be a great sounding valve. I don't agree that Global feed back is necessary to run them as Pentodes with pleasing results. I have been implementing feedback between the OPT S .......
405: Tube DIY Asylum, RE: Hammond power transformers are now made in China (0.00)
Posted by Stuben on 2012-05-16, 07:00:16 (66.117.237.162)
That blows...I thought I was supporting a market up North...not just the higher ups that out source...it's getting bad... Stuben .......
406: Tube DIY Asylum, RE: Anything to be gained or loss by two chokes in series vs. one in PS? (0.00)
Posted by Stuben on 2012-05-15, 15:26:36 (65.189.34.82)
I tend to use Hammond products for the the PS and Lundahl for the signal path. I acknowledge that the lines are blurred between the two but generally the Hammond products have served me just fine and .......
407: Tube DIY Asylum, RE: Best topology for a low gain pre (0.00)
Posted by Stuben on 2012-05-15, 12:44:38 (66.117.237.162)
I built a Blue Velvet...nice sounding Line stage...very natural IMO. It's a Mu follower...I believe that you're looking at a gain about 12. Stuben .......
408: Tube DIY Asylum, RE: Best topology for a low gain pre (0.00)
Posted by Stuben on 2012-05-15, 10:56:57 (66.117.237.162)
I like a rather high transconductance valve in a parafeed topology. I like a 5687 or 6h30p but these might have a MU maybe more than you're looking for. An opt like a LL1674 wired for low output imped .......
409: Tube DIY Asylum, RE: Leading is the beginning of Managing (or course while keeping ...) (0.00)
Posted by Stuben on 2012-05-12, 12:23:32 (65.189.34.82)
Amen to that:>) Stuben .......
410: Tube DIY Asylum, RE: Leading is the beginning of Managing (or course while keeping ...) (0.00)
Posted by Stuben on 2012-05-12, 10:34:14 (65.189.34.82)
Amen to that:>) Stuben .......
411: Tube DIY Asylum, RE: Just practice your bullshitting skills and lie, lie, lie! (0.00)
Posted by Stuben on 2012-05-12, 05:14:32 (65.189.34.82)
Well the joke at the Engineering firms that I have worked goes as follows: How do ya become a PM?...You get Bite by one:) With that said..there a few good ones out there...just hard to find. I think i .......
412: Tube DIY Asylum, RE: Mechanical Diodes (0.00)
Posted by Stuben on 2012-05-12, 05:01:20 (65.189.34.82)
Very Nice work... I'm presently using inexpensive Chinese made Non-over sampling DACs...nice sound for the price. K&K audio has a nice kit arrangement. http://www.kandkaudio.com/digitalaudio.html I've .......
413: Tube DIY Asylum, RE: Mechanical Diodes (0.00)
Posted by Stuben on 2012-05-11, 12:49:36 (65.189.34.82)
I've be wanting to get around to trying my hand at a DIY USB DAC. I'm still trying to perfect my earlier projects... I have a CF SE EL34 prototype in progress...has a promising sound. I just received .......
414: Tube DIY Asylum, RE: Why do we build amplifiers? Confessions of a DIY'er. (0.00)
Posted by Stuben on 2012-05-11, 08:53:06 (66.117.237.162)
It's a disease;>0 I know others will debate but, to date I've stuck with 50-60 ohm chokes in the input and have been satisfied with results...I'm sure things can always improve with lower resistance b .......
415: Tube DIY Asylum, RE: Mechanical Diodes (0.00)
Posted by Stuben on 2012-05-11, 08:45:22 (66.117.237.162)
I looked for your profile pics and I was wandering what sort of creations you had out there... BTW..There are some isolators out there that are that bring some serious cash on the audiophile market.. .......
416: Tube DIY Asylum, RE: Mechanical Diodes (0.00)
Posted by Stuben on 2012-05-10, 14:55:50 (65.189.34.82)
Henry, Are a builder of audio amplifiers? Stuben .......
417: Tube DIY Asylum, RE: I like your theory on (0.00)
Posted by Stuben on 2012-05-04, 17:00:53 (65.189.34.82)
:>) .......
418: Tube DIY Asylum, RE: I like your theory on (0.00)
Posted by Stuben on 2012-05-04, 16:35:32 (65.189.34.82)
Henry, You shit head. Dr. Kurt Bokonon??...Do you think no one has read Cat's Cradle?? Please don't fuck with us... Stuben .......
419: SET Asylum, RE: Antique Sound Labs ASL Tulip 2A3 (0.00)
Posted by Stuben on 2012-05-04, 15:08:25 (65.189.34.82)
Well I'm glad to hear that others well up the tear ducts...I have the same problem... The good thing about stimulants is also the bad thing... It's all about the spirit... I understand..:>) Stuben :: .......
420: Tube DIY Asylum, RE: A primer on Modern Physics as it relates to tube amp design (0.00)
Posted by Stuben on 2012-05-04, 14:29:36 (65.189.34.82)
Henry, Once again you have provided palatable explanations for complex subjects as it relates to our passion of music reproduction. Thank You I especially like your take on Heisenberg's Uncertainty Pr .......
421: Tube DIY Asylum, RE: He was talking about a filament supply ,,, (0.00)
Posted by Stuben on 2012-05-04, 07:47:13 (66.117.237.162)
My bad...might help to read the entire post ;.) Stuben .......
422: Tube DIY Asylum, RE: Can I safely use a can cap with a 1/4" dent in the side?... (0.00)
Posted by Stuben on 2012-05-03, 15:23:58 (65.189.34.82)
Chances are it's fine. If not you will hear a popping sound which will probably stop. Then potential has equalized at the weak point...then it might fine...regardless the performance if the device wil .......
423: Tube DIY Asylum, RE: What is the Z for a 300B when it is driven to A2 ? (0.00)
Posted by Stuben on 2012-05-03, 15:03:30 (65.189.34.82)
A 5687 CF can drive a 300B enough to let the magic out only if you put sufficient mu up stream. Stuben .......
424: Tube DIY Asylum, RE: Audibility of group delay (0.00)
Posted by Stuben on 2012-05-02, 15:22:22 (65.189.34.82)
There is lot's of masturbation going on in the forum.... It makes it very difficult for someone who aspires to be a good builder to use much of the data that is puked out... If we could all bring out .......
425: Tube DIY Asylum, RE: More progress (0.00)
Posted by Stuben on 2012-05-02, 15:08:46 (65.189.34.82)
Very nice...is this a mono amp? Stuben .......
426: SET Asylum, RE: Don't Forgret The... (0.00)
Posted by Stuben on 2012-05-01, 15:07:14 (65.189.34.82)
Sidewinder, All of my schematics are in Visio. I will pdf and get you a copy. Stuben .......
427: SET Asylum, RE: Type 50 Monos (0.00)
Posted by Stuben on 2012-05-01, 15:00:15 (65.189.34.82)
I tried a few and Ultimately the Mullard GZ34 was my choice. I run this rectifier in all of my amps. Expensive, but with simple designs, the rectifier has a real influence on the presentation. Stuben .......
428: SET Asylum, RE: Type 50 Monos (0.00)
Posted by Stuben on 2012-04-30, 17:27:23 (65.189.34.82)
Hey 1954, My non work e-mail address is michelestew@roadrunner.com. Stuben .......
429: SET Asylum, RE: Type 50 Monos (0.00)
Posted by Stuben on 2012-04-30, 17:14:34 (65.189.34.82)
Mullard GZ34s... I worked with many but the Mullard variants are the best. When you're working with such a simple circuit, the rectifier has a serious influence on the sound...you can definitely hear .......
430: SET Asylum, RE: how to multiamp a SET (0.00)
Posted by Stuben on 2012-04-30, 11:41:40 (65.189.34.82)
I agree with CutThroat.. Cash your old speakers and the extra mono blocks in and buy a set of sweet speakers that are SET friendly. Another approach, you eluded to, try a nice quality PP amp but 845s .......
431: SET Asylum, RE: Don't Forgret The... (0.00)
Posted by Stuben on 2012-04-30, 11:26:53 (65.189.34.82)
Gerry, Thanks..very cool..more flexibility in the future. I had considered installing some different OPT and filament trannys and changing the amps to 2a3s because of the 50s becoming silly rare... St .......
432: SET Asylum, RE: Type 50 Monos (0.00)
Posted by Stuben on 2012-04-30, 10:07:24 (65.189.34.82)
Thanks...We had a DIY get together at my place a few years ago and I think it was Larry Moore who said " A 50 is what a 300B wants to be" :>) They are hard to come by... I have (2) spare globe 50s. .......
433: SET Asylum, RE: Type 50 Monos (0.00)
Posted by Stuben on 2012-04-30, 04:39:08 (65.189.34.82)
Thanks These amps started as 45s. Because my speakers are not quite efficient enough to really let he magic out, I found some 50s to play with. I was starting up a foods plant and had some over tim .......
434: Tube DIY Asylum, RE: Recovery Time (0.00)
Posted by Stuben on 2012-04-29, 16:08:56 (65.189.34.82)
I'm a Lundahl user so I'll never see more than 101 Ohm static DCR on the primary. The LL1664 primary runs 74 ohm.... Stuben .......
435: Tube DIY Asylum, RE: PS Design- missing larger picture? (0.00)
Posted by Stuben on 2012-04-29, 14:58:18 (65.189.34.82)
Hey Neff, I thought that I'd throw in my 2 cents;>) At the risk of preaching to the choir... Some basic rules of thumb...keep the impedance as low as practical which includes the PS Transformer. I typ .......
436: SET Asylum, RE: another commentary... (0.00)
Posted by Stuben on 2012-04-28, 12:07:28 (65.189.34.82)
I have always had a simplistic view of thermonic devices compared to their SS brothers. The valve amplifier simply provides Harmonic distortion closer to the root than other methods of amplification. .......
437: Tube DIY Asylum, RE: Where do I put it? (0.00)
Posted by Stuben on 2012-04-24, 15:14:02 (65.189.34.82)
I have made this mistake. You're better off to avoid placing a resister in your B+ prior to the plate. I know you have already bought your power Tranny...;>0 In the future, buy a tranny that provides .......
438: Tube DIY Asylum, RE: This thing called The Second Law of Thermodynamics (0.00)
Posted by Stuben on 2012-04-21, 15:52:36 (65.189.34.82)
There nothing wrong with keeping an open mind...no need to worship anything or anybody... If folks in the past had listened to "Conventional Wisdom"...and concluded that there was nothing else, we wou .......
439: Tube DIY Asylum, RE: The Free Energy Motor, Laws of Physics & Vanity (0.00)
Posted by Stuben on 2012-04-21, 15:30:10 (65.189.34.82)
I'm using the term loosely...with questionable spelling ;>0 On the sub subatomic level we are in a sea of activity. This is where the pay dirt will ultimately be found. It's just a matter of time. Pra .......
440: Tube DIY Asylum, RE: The Free Energy Motor, Laws of Physics & Vanity (0.00)
Posted by Stuben on 2012-04-21, 12:08:01 (65.189.34.82)
I have always found Mr. Moray's approach interesting. The thought of harvesting energy from the "Ether" seems to cross both the physical and metaphysical worlds. His devices looked like vacuum tube de .......
441: Tube DIY Asylum, RE: Exciting Power Transformer, Amplifier (0.00)
Posted by Stuben on 2012-04-15, 15:08:05 (65.189.34.82)
Jeff, This could be the "Cats Ass" of the DHT amps. The 6SN7 is a wonderful input and the 45 plate current works perfect for a IT primary. I personally have not taken the next step for the higher volt .......
442: SET Asylum, RE: If the speakers were mine I think I would be more inclined (0.00)
Posted by Stuben on 2012-04-12, 16:43:01 (65.189.34.82)
Guys, The difference is the frequency of the harmonic distortion provided by a SS device compared the Thermonic device (Valves). Valves tend to be closer to the root. SS throw more power into the high .......
443: SET Asylum, RE: Crate (0.00)
Posted by Stuben on 2012-04-11, 15:52:52 (65.189.34.82)
Lakerfan, You might consider a Decware product using triode strapped EL84s. Much lighter and you could probably purchase one for what it would take ship your sweet amp. Stuben .......
444: Tube DIY Asylum, RE: The cases are extraneous (0.00)
Posted by Stuben on 2012-04-10, 17:59:40 (65.189.34.82)
The Russians designed their stuff to be unaffected by a large EMF pulse...like nuke deployment. A vacuum tube is much more resistant than a chip to such a pulse. Stuben .......
445: Tube DIY Asylum, RE: ll1660 phase splitter problem- help needed (0.00)
Posted by Stuben on 2012-04-08, 18:36:52 (65.189.34.82)
Slav1, Your driver plate impedance is too high for the this application. The IT primary will reflect the impedance of the driver so it needs to be fairly low.The rub is that when use a driver with low .......
446: SET Asylum, RE: Monaco 845 (0.00)
Posted by Stuben on 2012-03-24, 12:48:36 (65.189.34.82)
I heard the Monaco at a Cincinnati get together a few years ago. Larry did a great job on the design and build. This amp could be the best 854 offering out there. I haven't heard anything from Larry i .......
447: SET Asylum, RE: Single ended triode amp why they sound the way they do ? (0.00)
Posted by Stuben on 2012-03-21, 16:25:18 (65.189.34.82)
SE amps don't have the handicap of crossover distortion like their Push Pull brothers. It's the ole humpty dumpty bit. The PP amps have an inherent breaking of the signal, inverting half, and reassemb .......
448: Tubes Asylum, RE: What is a good new production 6SN7? (nt) (0.00)
Posted by Stuben on 2012-03-18, 07:46:23 (65.189.34.82)
I've tried the Savane EL34 offering with good results. They have a 6SN7 offering....looks pricey though... Stuben .......
449: Tube DIY Asylum, RE: Choke inductance - lower currents? (0.00)
Posted by Stuben on 2012-03-04, 05:25:46 (65.189.34.82)
Vidar, A SE topology will run class A. You won't see enough current swing to be concerned with your choke inductance range.Draw your load line on the published plate curves. Keep in mind that a Choke .......
450: Tube DIY Asylum, RE: Thorsten’s LCR RIAA – subtitled: “Boy, do I feel dumb”… (0.00)
Posted by Stuben on 2012-03-02, 13:23:52 (65.189.34.82)
GORDONny, Thanks for sharing your experience. This great information to put in the back pocket. The part about Oscillations manifesting into hum is a common theme. Stuben .......
451: SET Asylum, RE: Who try to build one like this? (0.00)
Posted by Stuben on 2012-02-24, 13:18:46 (65.189.34.82)
Wow, what a beast, linearity questions come to mind, but you can have your way with this one... Might have to pick one up and put an ear on it.... Stuben .......
452: SET Asylum, RE: Who here is running their 90 db speakers with ~ 2 watts? (0.00)
Posted by Stuben on 2012-02-18, 14:00:22 (65.189.34.82)
I think there are different degrees of "Letting the Magic out"... I'm running triode strapped SE EL84s in my family room (15X20), driving DIY back loaded horn boxes using $30.00 Tang Band 90db drivers .......
453: Tube DIY Asylum, RE: Best Operating point for 6H30P to drive SE 300B (0.00)
Posted by Stuben on 2012-02-10, 16:06:16 (65.189.34.82)
Tuck, Take a look at the below link: http://www.kandkaudio.com/transformers.html Lundahl offers several ITs for the application. I've used the LL1660s and the LL1692. The prices are not as hateful as .......
454: Tube DIY Asylum, RE: Best Operating point for 6H30P to drive SE 300B (0.00)
Posted by Stuben on 2012-02-09, 15:45:03 (65.189.34.82)
If you don't have to have a 3 stage amp, think about running just the 6H30P and put some gain in front of your amp. Simple is nice. I only have experience with the 6H30P driving the primary of an IT. .......
455: Tube DIY Asylum, RE: Long answer......history summation to date (0.00)
Posted by Stuben on 2012-02-04, 05:07:54 (65.189.34.82)
Jeff, Thanks...I've been initially hung up on the sub critical nature of L1. I will take some time and implement a similar supply on my test rig and put my ears to work... Thanks Stuben .......
456: Tube DIY Asylum, RE: "modern" PS for SE 811A's... (0.00)
Posted by Stuben on 2012-02-02, 17:21:28 (65.189.34.82)
Jeff, First off I must apologize for probably missing this value in previous strings, but what is the typical value of C1 in a sub critical design? BTW, you were spot on concerning the passive regs fo .......
457: Tube DIY Asylum, RE: Are Axon caps know for picking up hum? (0.00)
Posted by Stuben on 2012-02-02, 16:37:52 (65.189.34.82)
This magic sounds like HF oscillations cleverly disguised and you're playing the instrument.. Stuben .......
458: SET Asylum, RE: Capacitor or transformer coupling? (0.00)
Posted by Stuben on 2012-01-22, 07:32:04 (65.189.34.82)
I have built both. Although, I prefer IT coupling, RC coupling can sound great in a good design. The iron it takes to IT couple will run the BOM dollar amount way up. How about cap coupling with grid .......
459: Tube DIY Asylum, RE: Hammond P-T159T filter chokes... (0.00)
Posted by Stuben on 2012-01-21, 14:37:46 (65.189.34.82)
Jeff, Delivery...please...If you piss folks off, they will be hesitate to listen to you regardless of wisdom... I read your ham handed deliveries for years before I realized that you do have legitimat .......
460: Tubes Asylum, RE: 6SN7 rolling. (0.00)
Posted by Stuben on 2012-01-16, 16:29:49 (65.189.34.82)
Thought I would chime in ;>) I favor the Sylvania GTB chrome tops.. I have a pair of RCA coin based GTBs (later vintage)that have a more detailed sound than most of the other 6SN7s that I have.. inter .......
461: Tubes Asylum, RE: maybe it is catching on (0.00)
Posted by Stuben on 2012-01-15, 09:57:51 (65.189.34.82)
I had the same results... WE Amperex Raytheon is a distant 3rd If you think about it, this valve provides medium mu with the transconductance of a hot rod low mu triode...very amazing actually IMHO... .......
462: Tubes Asylum, RE: Psvane HiFi Series Tubes (0.00)
Posted by Stuben on 2012-01-14, 16:15:38 (65.189.34.82)
Correction...the Psvane site compares the Hi-Fi line to Shuguang basic valves... Stuben .......
463: Tubes Asylum, RE: Psvane HiFi Series Tubes (0.00)
Posted by Stuben on 2012-01-14, 14:03:24 (65.189.34.82)
I picked up a couple of Psvane HiFi 6CA7s. According to their web site, they are basic Shuguang valves. They are still breaking in but, they sound very nice and the build is decent. As far as inexpens .......
464: Tube DIY Asylum, RE: Sophia Electric Output Transformers (0.00)
Posted by Stuben on 2012-01-13, 16:12:35 (65.189.34.82)
No experience with Sophia Transformers.... Another option... http://www.kandkaudio.com/ I've been very happy with Lundahl. Kevin's always been very helpful. Not too hateful prices...good selection... .......
465: SET Asylum, RE: Radio from my 2a3 monoblock (0.00)
Posted by Stuben on 2012-01-09, 15:11:57 (65.189.34.82)
Hey cmathes, I had a similar issue crop up. My problem stemmed from a bad chassis ground connection. Assuming that you a metallic chassis and a chassis ground connection, this could be your problem. C .......
466: Tube DIY Asylum, RE: Any ideas about a very low gain linestage (0.00)
Posted by Stuben on 2012-01-08, 07:16:29 (65.189.34.82)
How about 5687..plates loaded with CCS... I chose to go Parafeed..not the cheapest approach. LL1674s for the OPT. Configured for about 200ohm out put impedance.. Probably not "Very" low in gain but I .......
467: Tube DIY Asylum, RE: My favorite bit of technology... (0.00)
Posted by Stuben on 2011-12-26, 05:48:03 (65.189.34.82)
I bias all of my output valves @ 42 mA...;>) Mr Adams put a lot of clever humor on the page... Cheers Stuben .......
468: Tube DIY Asylum, RE: Here is one am amply impressed by... (0.00)
Posted by Stuben on 2011-12-13, 16:05:14 (65.189.34.82)
Cleantime, Very cool, I've been a fan of the EF86 for a while...I hope to get to a project using a pentode a driver.... BTW...You might be able to help me..have ya seen a link to a 5847 data sheet tha .......
469: Tube DIY Asylum, RE: I have listened {and built} enough Amps to concur what Lynn Olsen has Said... (0.00)
Posted by Stuben on 2011-12-12, 16:17:19 (65.189.34.82)
Hey Cleantime, Point taken. I have been greatly inspired by the folks you mentioned. I'm at a stage in my building learning curve where I strapped Pentodes and Tetrodes for years and I ignored Gordon .......
470: Tube DIY Asylum, RE: I have listened {and built} enough Amps to concur what Lynn Olsen has Said... (0.00)
Posted by Stuben on 2011-12-12, 15:33:18 (65.189.34.82)
Hahax, I won't jump into the linearity discussion because I basically agree but I contend that a well executed Pentode amp will yield pleasing results with attributes that a SET will not necessarily r .......
471: Tube DIY Asylum, RE: I have listened {and built} enough Amps to concur what Lynn Olsen has Said... (0.00)
Posted by Stuben on 2011-12-11, 15:51:39 (65.189.34.82)
Yep, I concur but soo what! Build the same topology with a well regulated Pentode or tetrode, add a pinch of cathode feedback on the output and sit back and enjoy... There too many system variables fo .......
472: Tube DIY Asylum, RE: What is the primary inpedance? (0.00)
Posted by Stuben on 2011-12-04, 06:08:18 (65.189.34.82)
Here ya go...nice site, good reading http://www.nutshellhifi.com/triode2.html 6.6k Stuben .......
473: Tube DIY Asylum, RE: Any thoughts on Olsher's BLUE VELVET preamp? (0.00)
Posted by Stuben on 2011-11-13, 11:13:26 (65.189.34.82)
I built a Blue Velvet a few years ago. I have a real affection for the 6SN7. I have found the preamp to have a pleasing presentation without any hit of too much feedback from the plate follower. No no .......
474: Tube DIY Asylum, RE: one stage versus 2 stage driver (0.00)
Posted by Stuben on 2011-10-26, 15:45:25 (65.189.34.82)
Dan, I find listen fatigue is typically a result of lack of dampening on the part of the output (on my system). Note: I'm driving FE207s with mild baffle correction in a two way with a horn tweeter. .......
475: Tube DIY Asylum, RE: one stage versus 2 stage driver (0.00)
Posted by Stuben on 2011-10-25, 15:19:06 (65.189.34.82)
My ears tell me , with my home setup, a 2 stage amp increases sound stage, detail and provides a more "over all musical presentation" as I increase the transconductance of the driver.... until a gain .......
476: Tube DIY Asylum, RE: Hole Saws? Hammond Steel Chassis (0.00)
Posted by Stuben on 2011-10-14, 12:55:37 (65.189.34.82)
I'm where Rob is at. By the time you drill for the pilot bolt for a Greenlee you're almost there for a 3/4" penetration... The Greenlee is great for the Octals and larger...the 9 pin sockets with a st .......
477: Tube DIY Asylum, RE: My adventures with Decware's "Hazen Grid Mod" (long) (0.00)
Posted by Stuben on 2011-10-09, 06:54:11 (65.189.34.82)
So could this mod be another feedback mechanism using the AC response of the cap? Need to give a it try and a listen... Stuben .......
478: Tube DIY Asylum, RE: Anyone ever used this transformer? (0.00)
Posted by Stuben on 2011-10-05, 15:22:55 (65.189.34.82)
Picked up a couple a year or so ago $50.00 a pop. I've been happy with the purchase. Worth the money. I'm using them in a prototype that will ultimately get a couple of Lundahl LL1664..considered kee .......
479: Tube DIY Asylum, RE: Amp tech in Toronto wanted... (0.00)
Posted by Stuben on 2011-09-14, 15:23:52 (65.189.34.82)
Are you popping the fuse on startup? Stuben .......
480: Tube DIY Asylum, RE: Power Transformer (0.00)
Posted by Stuben on 2011-09-11, 15:06:54 (65.189.34.82)
Jeff, very cool..never thought about back feeding an industrial control power transformer... Big foot print ...nice price. Thank you for helping me thing outside the box... Stuben .......
481: Tube DIY Asylum, RE: simple el84 build (0.00)
Posted by Stuben on 2011-09-06, 15:12:32 (65.189.34.82)
I built a dual mono amp. A 400mA capacity is not really out of line if you're looking to keep your PS impedance down. Stuben .......
482: Tube DIY Asylum, RE: CF final stage (0.00)
Posted by Stuben on 2011-08-21, 10:08:08 (65.189.34.82)
GT, Another option is (2) halves of a 6SN7, You'll need either CCS or choke loading on (1) of the halves. Works well EL34s/KTs. Should get you close as far as voltage swing and have good transconducta .......
483: Tube DIY Asylum, RE: Paper in oil Capacitor in power supply?? (0.00)
Posted by Stuben on 2011-08-04, 15:56:26 (65.189.34.82)
I'm with Dan..look around and find NOS Motor Runs. I'm spoiled by being within 20 miles of Mendelsons in Dayton, Ohio...like a child in a candy store...;>0 If you make room for them up front....you'r .......
484: Tube DIY Asylum, RE: Cathode Follower Ouput (0.00)
Posted by Stuben on 2011-07-26, 15:21:19 (65.189.34.82)
Dan, I've given the amp a few hrs of listening and I'm convinced this the best sounding Tetrode/Pentode amp that I have built. With that said, my goal was to build a inexpensive (non DHT)amp that soun .......
485: Tube DIY Asylum, RE: Cathode Follower Ouput (0.00)
Posted by Stuben on 2011-07-23, 13:04:57 (65.189.34.82)
Dan, Nice work.. Still listening to mine. I'll give it a few hrs before I report back. Did you use the grid choke on the input? Stuben .......
486: Tube DIY Asylum, Cathode Follower Ouput (0.00)
Posted by Stuben on 2011-07-23, 11:10:10 (65.189.34.82)
Guys, Thought I would share this with the group... I've been working on an inexpensive alternative to a DHT design using tetrodes and Pentodes on the output while trying to get the most linear and mus .......
487: Tube DIY Asylum, RE: Parafeed tube rectified 45 (0.00)
Posted by Stuben on 2011-07-22, 13:57:47 (65.189.34.82)
See Gordon's designs...he's the man.. I've worked with a few rectifiers, the GZ34/5AR4, especially the Mullard variants are superior. You're going to pay...but if you have the "ear" you'll hear why fo .......
488: Tube DIY Asylum, RE: Sovtek 12AX7LPS. Are these cheapies any good ? (0.00)
Posted by Stuben on 2011-07-22, 13:34:50 (65.189.34.82)
I don't use many 12ax7s for audio but the LPS is probably my favorite of the New stock offerings. Stuben .......
489: SET Asylum, RE: Would You Buy a SET Amp Using DC Heating on the Output Tubes? (0.00)
Posted by Stuben on 2011-07-21, 15:44:02 (65.189.34.82)
DC heating CAN sound just as good with the right care taken in the design. With that said, you have to know what the builder/manufacture has provided in the heating design. I built a pair of mono bloc .......
490: Tube DIY Asylum, RE: grid choke comparisons (0.00)
Posted by Stuben on 2011-07-07, 16:39:07 (65.189.34.82)
This is the only experience I have with grid chokes.. Lundahl LL1670 540 H .8 mA I have loaded the grids of 5842s and 6H30P...great results. 90 bucks a pop... Stuben .......
491: Tube DIY Asylum, RE: Ken Gilbert - Gary Dahl interstage coupled 300b SET (0.00)
Posted by Stuben on 2011-07-05, 15:28:32 (65.189.34.82)
I'm using 5842/417a drivers in my 50 monos. Listen to what Jim says and you're OK. I applied stoppers to all 4 grids and used ferrite beads on the filaments. I've had no issues. Considering transcondu .......
492: Tube DIY Asylum, RE: Good responses. Here's mine. (0.00)
Posted by Stuben on 2011-07-04, 14:56:46 (65.189.34.82)
Well I think you received a few alternative definitions of "Warmth". That was probably the most productive point of your post ;>) I'll stick to "Accurate and Engaging"... If everyone is on board with .......
493: Tube DIY Asylum, RE: Poll question: Please tell me what you think are causes for system "warmth". (0.00)
Posted by Stuben on 2011-07-02, 06:35:48 (65.189.34.82)
Andy, Good point...maybe we should assign a definition to "warmth" Tube amps employing big global feedback with low trans conductive high gain drivers can sound "Bloated" ...way past Warm. As a builde .......
494: Tube DIY Asylum, RE: Poll question: Please tell me what you think are causes for system "warmth". (0.00)
Posted by Stuben on 2011-07-02, 06:01:10 (65.189.34.82)
In my builds this is always the last thing that gets improved after hair pulling...and it is elusive because of the variation of driver behavior. Amplifier Damping Wikipedia definition: In loudspeake .......
495: Tubes Asylum, RE: Replacing The Stock EH 6SN7 Tubes For Cary SLP 05 (0.00)
Posted by Stuben on 2011-07-01, 17:36:01 (65.189.34.82)
Sylvania Chrome Tops are my favorite after trying many NOS and NS,OS. Go on the prowl on E-bay...just be careful of what you're buying. Stuben .......
496: SET Asylum, RE: Custom SET Build Using Sonic Frontiers Power 3 Transformers (0.00)
Posted by Stuben on 2011-06-27, 15:18:42 (65.189.34.82)
Thanks Dan, I should read all of the posts before I post... My post assumes a PP tranny with a wide enough response. Chris .......
497: SET Asylum, RE: Custom SET Build Using Sonic Frontiers Power 3 Transformers (0.00)
Posted by Stuben on 2011-06-25, 07:02:20 (65.189.34.82)
Never tried it in a power amp, but a parafeed topology would nullify the current issue. You have more iron involved which might hose your ROI if you're trying to reuse PP iron and save money. Just a t .......
498: Tube DIY Asylum, RE: amp plays music without speakers (0.00)
Posted by Stuben on 2011-06-19, 07:32:59 (65.189.34.82)
It's tough on amps to run them without loads. As other have said...not a good practice. Just disconnect one channel and see if the unloaded channel has any influence over the loaded side...might be in .......
499: Tube DIY Asylum, RE: Painting motor run caps.... (0.00)
Posted by Stuben on 2011-06-19, 06:21:47 (65.189.34.82)
Self etching primer Go to your local auto parts store and inquire...that's where I purchased mine. Stuben .......
500: Tube DIY Asylum, RE: Painting motor run caps.... (0.00)
Posted by Stuben on 2011-06-18, 09:29:59 (65.189.34.82)
You're looking to get to get rid of the aluminum oxide which impedes on the paint sticking to the metal part of the process. Stuben .......
Found total of 500 records, Query: , Author: Stuben in All Forums, Time: 1 sec.