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1: Tube DIY Asylum, RE: What would you use to fill in the air gap of a SE OPT? (0.00)
Posted by walge on 2024-03-02, 05:54:04 (93.35.220.52)
some old methode Walter .......
2: Tube DIY Asylum, RE: When negative feedback is not beneficial (0.00)
Posted by walge on 2024-01-17, 07:57:18 (37.159.54.19)
this is the circuit of Rogers RD and some additional notes. There are some differences!!!!!!!!! Walter .......
3: Tube DIY Asylum, RE: Question about LCR Phono (0.00)
Posted by walge on 2023-09-03, 00:00:52 (93.35.218.80)
This is the original Shishisdo LCR And there is the Rk on lower tube Walter .......
4: Tube DIY Asylum, RE: Whether my linestage has enough gain? (0.00)
Posted by walge on 2023-08-10, 03:07:42 (37.159.61.156)
I can agree with a low gain. The ratio is 4:1 and the 6SN7 hasn't a enough mu. One good configuration is SRPP of 6SN7, p.e. Then switch the input cap to 1 uF, 10K is a low value. The for Sut I thin .......
5: SET Asylum, RE: Those are GE tubes (0.00)
Posted by walge on 2023-03-14, 23:42:04 (93.35.218.136)
Hi Are RCA Walter .......
6: SET Asylum, RE: Those are GE tubes (0.00)
Posted by walge on 2023-03-14, 23:38:43 (93.35.218.136)
One pair Walter .......
7: SET Asylum, RE: Those are GE tubes (0.00)
Posted by walge on 2023-03-14, 20:17:15 (93.35.221.60)
Hi Are RCA Walter .......
8: SET Asylum, RE: What's your favorite 845 tube? (0.00)
Posted by walge on 2023-03-14, 07:19:03 (93.35.222.201)
I have some of 845 Fivre (RCA) from 1942; matched in pair. Nos no Box. Walter .......
9: Tube DIY Asylum, RE: Seeking Comments about two Phono Stages (0.00)
Posted by walge on 2022-08-22, 01:52:42 (5.90.110.187)
The Zout of Shishido is around 200 ohm. So the coupling with a proper cap is good .......
10: Tube DIY Asylum, RE: Seeking Comments about two Phono Stages (0.00)
Posted by walge on 2022-08-21, 05:13:54 (79.143.117.121)
The quality is strictly related ot the price, unfortunately. This trafo seems to be at the entry level point .......
11: Tube DIY Asylum, RE: Seeking Comments about two Phono Stages (0.00)
Posted by walge on 2022-08-21, 05:12:11 (79.143.117.121)
70 dB is a lot of gain. I think that a range of 60-63 dB can be enough But the match of step uo with thye Z of MC is very important .......
12: Tube DIY Asylum, RE: Seeking Comments about two Phono Stages (0.00)
Posted by walge on 2022-08-20, 04:40:32 (79.143.117.121)
Also: Claus Weber, āRIAA LCR Filter Mythos Or How to Design" .......
13: Tube DIY Asylum, RE: Seeking Comments about two Phono Stages (0.00)
Posted by walge on 2022-08-20, 04:36:58 (79.143.117.121)
There is good paper on LCR https://www.sowter.co.uk/pdf/LCR-RIAA%20Ahlswede.pdf lot of info .......
14: Tubes Asylum, RE: 6h30 Supertube (0.00)
Posted by walge on 2022-08-19, 03:04:06 (217.20.250.183)
Also the 6N6 russian, similar to 6H30, with a good selection is a fine tube. Otherwise there is a 7044 nos it is also good but expensive Walter .......
15: Tube DIY Asylum, RE: Seeking Comments about two Phono Stages (0.00)
Posted by walge on 2022-08-19, 03:00:44 (217.20.250.183)
Hi the 600 ohm at the end of LCR is mandatory. Thne with 38 dB of gain and 10x of step up you got 58 dB that is enough for a MC with around 30 -40 ohm of impedance and 0,3 mV of output voltage; the r .......
16: Tube DIY Asylum, RE: Seeking Comments about two Phono Stages (0.00)
Posted by walge on 2022-08-12, 12:05:34 (5.90.104.40)
The gain of Shishido is around 36-38 dB I have tested it with Tango stuff and run very fine Walter .......
17: Tube DIY Asylum, RE: Nice Gomes - my circuit with ECC40 (0.00)
Posted by walge on 2022-03-13, 04:46:54 (212.69.137.173)
Other info .......
18: Tube DIY Asylum, RE: Nice Gomes - my circuit with ECC40 (0.00)
Posted by walge on 2022-03-13, 04:37:10 (212.69.137.173)
Hi in attach the diagram done in Audioreview from a particular software wrote by mu collegue Montanucci ( directr od the lab) who check in deep the principal aspect of the trafo, in this case the .......
19: Tube DIY Asylum, RE: My 2a3 amp experiences (0.00)
Posted by walge on 2022-03-12, 11:38:20 (5.90.73.250)
This is my old project of a s.e. 2A3 with input stage with Gomes circuit. Very good. The input circuit the tube is 6N1P .......
20: Tube DIY Asylum, RE: This idea has been employed years past ... (0.00)
Posted by walge on 2022-03-04, 01:57:57 (93.35.219.4)
Which tecnique for MX110? Walter .......
21: Tube DIY Asylum, RE: How to use a bolt to improve hum spectrum (0.00)
Posted by walge on 2022-03-03, 09:28:13 (93.35.223.252)
A solution done in 1997 on an Audioreview project where I have partecipated; it is a Smart Audio Driver ( in this case in current, it is multi configurable, class A and A/B) There are three coils, .......
22: Tube DIY Asylum, RE: Can a Voltage Doubler Work Right Off Of Line Voltage? (0.00)
Posted by walge on 2022-02-20, 03:20:35 (93.34.160.4)
You must use a power tranformer for security reason first of all. Using the 1:1 ratio then the doubler. This isolate from mains and you stay safe. So you can put to ground the chassis after rectificat .......
23: Tube DIY Asylum, RE: it is serious, Pak ... (0.00)
Posted by walge on 2022-01-14, 05:34:02 (185.86.200.38)
the best way to test the OT trafo is to use the backward way. In attach the base circuit. The amp is a good ss amp. In this way iti is possible to have the real results. In a normal way is not p .......
24: Tube DIY Asylum, RE: You're right (0.00)
Posted by walge on 2022-01-04, 05:56:42 (93.35.223.212)
I have worked on AN stuff, my opinion is they have a personal idea of the sound and they build the stuff in that way. Under the test lab they are not good as performances; also the THD vs. frequency i .......
25: Tube DIY Asylum, RE: What would be the sonic effect for this Audionote line stage (0.00)
Posted by walge on 2022-01-03, 10:53:15 (93.35.219.92)
In addition the Zout is higher due the non bypassed Rk Walter .......
26: Tube DIY Asylum, RE: Results so far (0.00)
Posted by walge on 2022-01-02, 12:42:03 (93.35.221.214)
Do you have a minimun of test set? Check with a good voltmeter in ac if there are differences in ripple residual on HT between channels In case maybe a Cap is defective .......
27: Tube DIY Asylum, RE: Results so far (0.00)
Posted by walge on 2022-01-01, 13:33:40 (93.35.221.214)
Do you have a minimun of test set? Check with a good voltmeter in ac if there are differences in ripple residual on HT between channels In case maybe a Cap is defective .......
28: Tube DIY Asylum, RE: Results so far (0.00)
Posted by walge on 2022-01-01, 09:21:14 (93.35.221.214)
The hum appaer with the input of both channel shorted? If you have a scope you can check the type of residual, if it is 50(60)Hz it comes a magnetic coupling, BUT not from OT trafo because on p-p ther .......
29: Tube DIY Asylum, RE: 300B IT 1:1 845, A2 possible? (0.00)
Posted by walge on 2021-12-31, 04:57:04 (93.35.221.214)
The curves of 845 haven't the portion in positive grid and it is the fact So I can't understand why you push in A2 where the grd current is not linear and the drive circut is more complicated and the .......
30: Tube DIY Asylum, RE: FYI (0.00)
Posted by walge on 2021-11-14, 10:17:46 (79.143.120.130)
Write in english the same phrase. And the others. Ciao Walter .......
31: Tube DIY Asylum, RE: Loudness control or tone control? (0.00)
Posted by walge on 2021-11-14, 09:52:49 (79.143.120.130)
In the past some brand as Yamaha put on some amps a variable loudness and the tone control. Also McIntosh did something similar, if I remember well. In my opinion, for loudness, it will be better than .......
32: Tube DIY Asylum, RE: FYI (0.00)
Posted by walge on 2021-11-14, 09:24:14 (79.143.120.130)
Your first assertion was general. Now you are moving the concept. Climbing on glass. And, normally , in the circuit for hifi there aren't solution as one reported on Radiotron that is a beautiful book .......
33: Tube DIY Asylum, RE: Good point (0.00)
Posted by walge on 2021-11-12, 09:52:15 (79.143.120.130)
The problem is not the simulation. The problems are the message technically wrong as to add the cap on FB in a amp to solve the peak on tone control, if it is too high! Walter .......
34: Tube DIY Asylum, RE: Good point (0.00)
Posted by walge on 2021-11-12, 04:37:55 (5.90.230.216)
Flame? You have posted some wrong information and only simulation. With some ridicoulus suggestion as put a cap on FB putting the amp a risk of instability if not well verified and tested!!!!! This is .......
35: Tube DIY Asylum, RE: Good point (0.00)
Posted by walge on 2021-11-11, 23:53:19 (93.35.221.6)
As usual the simulation is not the truth so your consideration are only virtual Then you comment on change the FB is out of the real world. In practical I have to change the power amp to allow the use .......
36: Tube DIY Asylum, RE: Universal tone control for DIY (0.00)
Posted by walge on 2021-11-11, 05:31:51 (93.35.217.194)
The circut is fine and tested. I can't understand what are you saying. Walter .......
37: Tube DIY Asylum, RE: Universal tone control for DIY (0.00)
Posted by walge on 2021-11-11, 04:16:38 (93.35.217.194)
This is a project of a Line preamp with a optional tone control published by me on Audioreview magazine in Italy This is the tone control THne the repsonse of the tone It is possible the use .......
38: Tube DIY Asylum, RE: Think about the purpose (0.00)
Posted by walge on 2021-10-31, 05:25:25 (93.35.223.198)
The connection to ground is mandatory for security reason!!! Each equipments with double isolation has the chassis to ground and can have the electrical ground isolated. So if you have multiple stuff .......
39: Tube DIY Asylum, RE: Think about the purpose (0.00)
Posted by walge on 2021-10-31, 04:54:43 (93.35.223.198)
Again, think about the ground connection. Please answer with your words not with link. Walter .......
40: Tube DIY Asylum, RE: Insulation transformer (0.00)
Posted by walge on 2021-10-31, 01:25:43 (93.35.218.246)
Think about the ground layout. From wall socket until the equipments Walter .......
41: Tube DIY Asylum, RE: Insulation transformer (0.00)
Posted by walge on 2021-10-30, 09:36:11 (93.35.222.34)
Error It is not the right way Walter .......
42: Tube DIY Asylum, RE: un-documented P-P OPT secondary wiring question (0.00)
Posted by walge on 2021-08-12, 11:34:13 (217.20.249.213)
The correct Z adapting is done only in this way About the dissipation it is a secondary aspect. If you have a base test set up you can check the differences Walter .......
43: Tube DIY Asylum, RE: un-documented P-P OPT secondary wiring question (0.00)
Posted by walge on 2021-08-12, 11:18:31 (217.20.249.213)
Hi in attach a base concept; this solution is a very good way to test the OT trafos but also to get a high output signal. When connected to the right load also the Thd is fine; of course at low .......
44: Tube DIY Asylum, RE: un-documented P-P OPT secondary wiring question (0.00)
Posted by walge on 2021-08-12, 05:06:46 (5.90.136.42)
to Joris To have a perfect connection you MUST use at the output od the SS amp a resistor with the same value of the tap. If you connect the 16 ohm you will use a 16 ohm, maybe 20w, resistor in series .......
45: Tube DIY Asylum, RE: 12 volt 6DJ8? (0.00)
Posted by walge on 2021-05-29, 09:43:55 (93.35.216.114)
Use a 7806 before then connect the 88 Walter .......
46: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-05-24, 04:56:10 (79.143.117.89)
This is the last version pf pcb, just little changes from proto Walter .......
47: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-05-02, 12:15:42 (5.90.164.201)
Hi I know well the problem and, when possible I use a low value of pot. In the last numbero of Audioreview magazine there is a presentaion of a potential kit of pot with 6 relč and a (almost) costant .......
48: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-05-02, 11:36:05 (5.90.164.201)
So I need to select at the best the source otherwise I will get a peak or a low pass? This is a limit for me. Walter .......
49: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-05-02, 11:33:42 (5.90.164.201)
I agree with you about this type of volume control. Walter .......
50: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-05-02, 11:31:40 (5.90.164.201)
The approach the the tests are done just to show what the presentr want is out of the reality. When we test the equipmente on Audioreview magazine these tests follows ( in part) the intl indication th .......
51: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-05-01, 12:38:09 (79.143.119.35)
Please send the test at - 6dB from the max position of volume. Which brand is the pot? Walter .......
52: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-05-01, 11:49:16 (79.143.119.35)
Hi excuse me but I can't understand what are you sayng Walter .......
53: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-05-01, 05:37:10 (212.69.138.156)
I can't undestand why there are a posts around trafo volume control. Then the use of CF to drive in A2 is a bad solution due the non linear current in a grid of power tube because the impedance falls .......
54: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-04-30, 05:02:28 (5.90.110.101)
Hello, the only way to understand what happen in the real world is to test the circuit in the lab and not with simulation. For this reason I confirm that the configuration of the LCR circuit is fine; .......
55: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-04-29, 01:49:53 (93.35.216.114)
As wrote before, I will publish the project only after an intesive listening tests. Of course, the lab test must confirm the specs, as you can see from the results I published here. Having more than a .......
56: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-04-29, 01:41:00 (93.35.216.114)
Hi personally, as said, I don't like to mix sand with tubes. Walter .......
57: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-04-28, 12:31:55 (93.35.216.114)
Hi Yes but in my opinion there isn't a reason to use it when you have a simplest way to follow Walter .......
58: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-04-28, 10:21:01 (93.35.216.114)
I don't want to mix sand with tubes, so the CCS is not considered. My opinion. The only use of sand is in HT power supply because the goal is to kill the ripple and get low Zout The reason to use in t .......
59: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-04-28, 06:07:23 (91.80.12.124)
Ok But a 6H30 will be a very good choice for that job Walter .......
60: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-04-26, 11:53:51 (93.35.190.176)
I forgot this one Done years ago. Useing pentode in gain stage Walter .......
61: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-04-26, 11:49:27 (93.35.190.176)
Hi I always done the RC phone like this It is a Junior phono, the LCR stage took something from this project. The use of Tango style LCR is a challenge for me and the results are very fine. The i .......
62: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-04-26, 05:14:18 (93.35.190.176)
In attach the last of four protos I made for tests before this one. It is full Tango MCT-999 EQ-2L NP-206 x 3 ( and 11103 x 2)+ other for test Good performance and very good sound. I am preparing the .......
63: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-04-26, 01:43:20 (93.35.190.176)
The frequency response is the first parametere to look just to be compliant with RIAA specs. Then other test must be done. Normally it is very interesting for me to discuss around circuit but the co .......
64: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-04-25, 08:22:15 (93.35.190.176)
No I am planning to do something in next two weeks I am waitng the inductors from Sowter and the new pcb Walter .......
65: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-04-25, 07:16:22 (93.35.190.176)
If we look at impedance only with a source of 600 ohm and closed with same Z we got the real costance. As my post where I put the freq answer with diffferent Zsource now I put the resposłnse with 600 .......
66: Tube DIY Asylum, RE: Can someone explain this phase inverter circuit to me? (0.00)
Posted by walge on 2021-04-25, 03:26:53 (93.35.190.176)
Is it possible to have the component list to undertand the * on some value. I have another idea around Walter .......
67: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-04-25, 03:03:09 (93.35.190.176)
Hi In attach some test lab ( not simulation!)n about a LCR stage driven with different Zsource but it closed to 600 ohm ( as Tango spec) It is a freq. response. As you see there is a good answer fir d .......
68: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-04-22, 22:43:22 (93.35.190.176)
Hi Thx The tube are ecc81 as gain stage and ecc88 ad C F But is possible to use other changing the pad for filamenti Now the gain is 40 db I am planning to offer the pcb Walter .......
69: Tube DIY Asylum, RE: LCR Phono stage (0.00)
Posted by walge on 2021-04-22, 11:08:09 (93.35.190.176)
Thx Not now because it is on magazine that is selling. I will send some other info soon Walter .......
70: Tube DIY Asylum, RE: VR Tubes for Screens (0.00)
Posted by walge on 2021-04-22, 05:11:14 (93.35.190.176)
Which is the HT voltage? Are you using 6L6GC? Look at maximun ratings. As I said before and don't worry. Is not possible you have a screen voltage greater than anode voltage. If you have 450 Vdc on an .......
71: Tube DIY Asylum, LCR Phono stage (0.00)
Posted by walge on 2021-04-22, 04:50:33 (93.35.190.176)
Hi In attach the photo of LCR board, the LCR phono stage and the complete proto . I wrote some article on LCR on udioreview magazine in Italy. And I hve done four proto with Tango original st .......
72: Tube DIY Asylum, RE: Schematics (0.00)
Posted by walge on 2021-04-21, 08:56:57 (93.35.190.176)
Hi are two different topology of circuit. You can't see only the HT voltage but also the type of bias. On is autobias (Bogen) and other is fixed bias. The Bogen maybe is in class A for a good range of .......
73: Tube DIY Asylum, RE: 6L6 Specs (0.00)
Posted by walge on 2021-04-21, 02:37:21 (93.35.190.176)
You have to look always at the maximum ratings. For 6L6GC the RCA says 500 Vdc for Anode and 500 Vdc for G2 in a p-p Same for GE Then, in a p-p, with a proper load and a reasonable Ibias you stay safe .......
74: Tube DIY Asylum, RE: Beautiful Amps! (0.00)
Posted by walge on 2021-04-14, 07:44:13 (2.35.112.92)
Thanks I have done some stuff also with different tubes as KT120 and KT150, same aesthetic. The driver stage ia ECC88 + 6H30; very strong and very linear. The amps are quite also with 300B with the fi .......
75: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-11, 07:34:11 (91.80.11.182)
Ok If not here Where? .......
76: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-11, 07:03:52 (91.80.11.182)
Good! It is possible to buy or not? .......
77: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-11, 06:04:07 (93.35.190.176)
Ok, I understand. At the end of the story you can't give any addtional specs or photo on the stuff you mentioned. It seems a virtual world. If I have the OT like you description I will be in hurry .......
78: Tube DIY Asylum, RE: Some people can't wait for Mouser or Digi-Key orders (0.00)
Posted by walge on 2021-04-11, 04:31:01 (93.35.190.176)
like condom! Walter .......
79: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-11, 04:27:17 (93.35.190.176)
Please decribe the test set up. will buy this trafo for my test, please send details. PS= it is funny, you show a diagram of one trafo seems to be fine but, then after my request to buy it, you wrote .......
80: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-10, 13:02:18 (93.35.190.176)
I forgot. If you aren't interested on bi-directional question is not a problem for me, of course. The fact that you don't answer is clear for me. Then, your opinion on large signal is opinable and not .......
81: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-10, 12:35:14 (93.35.190.176)
I will repeat again. On OT trafo you don't reach that type of answer. I mean only trafo not involved on a circuit And please explain which type of signal you are using and the circuit; for a .......
82: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-10, 07:39:09 (5.90.225.70)
To be precise I wrote more than one time that the trafo are bi-directional device without any comment by you. Then, I wrote that, in my opinion, the test set I propose is the best to check in deep the .......
83: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-10, 06:27:36 (5.90.128.27)
My point of view is based on electronic. If you are agree that a trafo is a bi-directional device you can agree with my test set. You didn't explained why this test set is not correct, you have shown .......
84: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-10, 05:10:45 (93.35.190.176)
I must measure all parameters from minimum to maximum. If I spend money or I ask to have a custom trafo I need to know all specs. Where is the problem? I show you the simplest way to do this. If you d .......
85: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-10, 03:09:16 (93.35.190.176)
I repeat again. The each trafo is a bi-directionl device. The only way to understand the real performance of itself are: 1- a generator that can give the nominal Vac ( for different Rsource) on primar .......
86: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-10, 00:01:00 (93.35.190.176)
Please decribe the test set up. What I said before that the set up I described is similar to the real use of the OT trafo. This make a great difference. Also regarding the signal test. When you say th .......
87: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-09, 11:22:40 (93.35.190.176)
To find a good ss amp is not complicated. In the photo you can see on proto of test se a board that is a fet amp with the BW of 200 kHz, measured with AP. 120 watt rms. Around 50 euros, it is a kit, e .......
88: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-09, 09:57:52 (93.35.190.176)
In my opinion is always better to know how good is the OT trafo where you are playing. This means that a complete test set is preferable. And this method is the simplest way to know the quality of OT. .......
89: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-09, 08:33:38 (91.80.11.182)
The trafo on test is a big one. On photo is one the right side It is double C core amourphos laminate 0,023 mm The resonance is fine at that frequency But we are out in this thread. In case I will ope .......
90: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-09, 00:56:45 (93.35.190.176)
Hi the Tango is fine but I never seen a heavy test as you can get with the method I say. There is no way to get a great swing with low distortion, this is the fact. The results I show is f .......
91: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-08, 13:13:11 (91.80.11.182)
The trafo on test is a big one. On photo is one the right side It is double C core amourphos laminate 0,023 mm The resonance is fine at that frequency But we are out in this thread. In case I will ope .......
92: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-08, 12:47:47 (91.80.11.182)
In addition there is another consideration Each trafo is a bi-directional device Walter .......
93: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-08, 12:32:59 (91.80.11.182)
The plot are about single ended The main problem is to test the trafo itself Without the tube And this is the easiest and efficent way And with a properly interface it is possible to use a good sound .......
94: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-08, 10:55:36 (93.35.190.176)
I am not agree. You can measure the s.e. and p-p really This the only way to know the real performanceso of the trafo Inside the circuit you have the tube charateristic that modify the results. .......
95: Tube DIY Asylum, RE: 38H OPT for 845, so so? (0.00)
Posted by walge on 2021-04-08, 03:11:42 (93.35.190.176)
The measurement is done without the bias current So the real L at low frequency, in this case, will be greater than the real use. The best way to measure the OT trafo is driving it on secondary wit .......
96: Tube DIY Asylum, RE: Add XLR output in tube preamp (0.00)
Posted by walge on 2021-04-04, 09:59:31 (79.143.119.85)
Please post the schematic of connection. Walter .......
97: Tube DIY Asylum, RE: Please teach me this cathode bypass question (0.00)
Posted by walge on 2021-03-29, 06:58:49 (91.80.4.121)
What do you think to resolve ? Can you measure the differences? To understand if it convenient Which is the complete circuito? Walter .......
98: Tube DIY Asylum, RE: Please teach me this cathode bypass question (0.00)
Posted by walge on 2021-03-28, 13:00:38 (93.35.190.176)
the proper diagram is the first. At the conjuction of the two resistor you must connect the resistor ( maybe a cap for compensation) comes from secondary of OT With this configuration you can have a g .......
99: Tube DIY Asylum, RE: Low frequency response: Quite the opposite is true! (0.00)
Posted by walge on 2021-03-23, 14:09:41 (91.80.15.210)
This is a great error Walter .......
100: Tube DIY Asylum, RE: Low frequency response: Quite the opposite is true! (0.00)
Posted by walge on 2021-03-22, 14:20:25 (91.80.9.75)
This is a great error Walter .......
101: Tube DIY Asylum, RE: RE-RE: If you do not trust simulations do not use simulations. (0.00)
Posted by walge on 2021-03-21, 06:58:49 (5.90.195.122)
Hi you are in Roma like me. I have a lab if you want we can test the real circuit at the best. Which lab equpment you have? Walter Gentilucci .......
102: Tube DIY Asylum, RE: If you do not trust simulations do not use simulations. (0.00)
Posted by walge on 2021-03-21, 06:09:44 (217.20.251.75)
Each simulation is a limit until you don't realize the real circuit. There are thousands of people that published simulation on tube stuff without any real test on a real world. This is a problem. Whe .......
103: Tube DIY Asylum, RE: How to convert plate to plate impedance to turns ratio and to inductance (0.00)
Posted by walge on 2021-03-21, 05:42:56 (5.90.14.78)
In attach three test done by a pearticular software developped by F. Montanucci in Audioreview in Italy ( not commerciaL ). The test was done aroudn some article I wrote on tube amps. It is possibl .......
104: Tube DIY Asylum, RE: Low frequency response: Quite the opposite is true! (0.00)
Posted by walge on 2021-03-20, 13:44:05 (217.20.251.75)
This is a great error Walter .......
105: Tube DIY Asylum, RE: When modeling ultralinear a doubt arises.., (0.00)
Posted by walge on 2021-03-20, 12:38:48 (5.90.136.51)
Hi standard the UL ( partial triode operation) is 43% from the top end of each section. In some cases it is 20 % but not normal The UL is a trick to get a double goal. First a better linearity of tube .......
106: Tube DIY Asylum, RE: The paraphase phase splitter is alone. (0.00)
Posted by walge on 2021-03-17, 12:30:52 (5.90.132.165)
Leave the simulation. Try the test in the real world. It is better and more attractive. Walter .......
107: Tube DIY Asylum, RE: SRPP (0.00)
Posted by walge on 2021-03-14, 12:47:09 (5.90.207.137)
Never leave the filaments floating. A simple partition with resistors and one cap to elevate them is the best way. With a proper bias point the Zout is around 100-120 ohm A ggod alternative is 6N6 rus .......
108: Tubes Asylum, RE: Testing A JJ 2A3-40 (0.00)
Posted by walge on 2020-06-21, 11:20:27 (79.143.119.238)
It is a 300B with 2,5 volt filaments Walter .......
109: Tube DIY Asylum, RE: Anyone got a schematic for a preamp w/bass&treble controls other than pas Dynaco (0.00)
Posted by walge on 2020-03-18, 08:02:28 (93.35.191.32)
Hi in attache a schematic of a line preamp with an option of tone control. It is working great; I am preparing the board also fot the pots. You can have the possibility the use of tonr or not si .......
110: Tubes Asylum, RE: Tektronix type 570 curve tracer (0.00)
Posted by walge on 2019-07-15, 08:42:56 (93.44.99.32)
Hi let me hceck the postage to Italy. How much is the weight? Walter .......
111: Tubes Asylum, RE: Tektronix type 570 curve tracer (0.00)
Posted by walge on 2019-07-06, 12:27:24 (5.92.65.237)
Hi my email walge@mclink.it Bye Walter .......
112: Tubes Asylum, RE: Tektronix type 570 curve tracer (0.00)
Posted by walge on 2019-06-29, 03:10:06 (79.143.121.199)
Hi I am in Italy. Do you think we can speak about your 570? Walter .......
113: Tubes Asylum, RE: KT 120, first impressions (0.00)
Posted by walge on 2011-12-19, 09:43:20 (89.97.69.99)
Hi, I have published a project on italian magazine Audiocostruzione (http://www.audiocostruzione.it/) It is a pushpull of KT120 ( is possible to use also EL34). The technical mesurements are very inte .......
114: Tube DIY Asylum, RE: ground loop isolators... (0.00)
Posted by walge on 2010-02-01, 12:45:44 (151.32.49.33)
If with only one amp connected with signal cable, the hum disappear, the solution can be to put one resistor of 10 ohm 1/w in series with each ground cable close to input pin jack. It break the loop a .......
115: Tubes Asylum, RE: Recent JJ 300B buyers (0.00)
Posted by walge on 2010-01-09, 09:37:19 (151.32.49.80)
Hi, I bought many JJ 300B, they are robust with a good glass and internal elctrodes. The specifications are close to the W.E.. Only one samples was defective and my supplier change it in warranty. Re .......
116: Tube DIY Asylum, RE: Help with a VTL Deluxe 300....... (0.00)
Posted by walge on 2009-06-14, 12:26:52 (151.32.52.174)
Hi, this amp has a secondary power supply for the input stage. There is a small trafo on left side with a bridge and caps ( if I remember well). Check the voltage on input tubes on each anode (maybe c .......
117: Tube DIY Asylum, RE: Your DHT alternatives. (0.00)
Posted by walge on 2008-10-16, 05:44:24 (83.103.90.54)
Hi, I am working with Gomes circuit; it is very interesting. With a 6SL7 in this configuration you can reach a swing , with 1 v rms input, about 55 vrms out; this means 157 V p-p, quite enogh to drive .......
118: Tube DIY Asylum, RE: 300b distortion test fun (0.00)
Posted by walge on 2008-10-13, 05:10:12 (83.103.90.54)
Hi, the distortion you have (if THD) is not bad. The problem is to understand the shape of it; have you a FFT analyzer? If it is mainly IInd, it is good; with FFT you can check at which level is the I .......
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