Re: New test suggested from GR

Posted by glc (A) on February 4, 2004 at 14:03:21

In Reply to: Re: Some things to check-my answers posted by Gordon Rankin on February 4, 2004 at 09:36:51:

Gordon, I tried with a 220ohm (I havent 100ohm) between the connection ECC83 plate - 6A3 grid. There isnt voltage (ac or dc) across the 220ohm resistor and at the output persist 12mV ac.
About ground:
I used a common ground for each stage: right Ecc83, right 6a3, left ecc83, left 6a3,plus separate ground from each filtering capacitor and ground from a side of each output transformer secondary (I tried to remove output transformers output connection to star ground but again noise 12 mV persist).
Each common ground connect to the star ground where also the center wire of power transformer secondary is connected. The star ground connect to the chassis connected to power company ground. I tried also to disconnect star ground from chassis and power company ground but the 12-14mV ac noise again persist.
I tried each ground for cold solder but all soldered joints seem good.
I am thinking to try with the E83CC Ultron and VT52 Hytron to see if noise will reduce: what do you think?
I have understood your opinion about cathode capacitors, but I dont know what is a "matched pair in L cancelling Black Gate topology".
About the Loftin White (or direct coupling) now I understand that it is not a simple circuit. I choiced it becouse with E83cc+VT52 I found only Loftin White circuits. Really the only circuit with cap coupling was WE310A+VT52 and I havn't a WE310A nor I doesnt know where to find them. Take note that I had here E83CCs and VT52s bought from 20 years at very low price and stored in a box since then - hi.
Thanks.
Gian Luca

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Follow Ups Full Thread

Topic - SET VT52 amplifier; 12-14mV hum noise is too high? - glc 03:28:21 02/1/04 (21)

Re: SET VT52 amplifier; 12-14mV hum noise is too high? - groverg 16:55:34 02/2/04 (0)

Few suggestions - Gordon Rankin 06:32:31 02/2/04 (12)

Re: postum scriptum for Gordon Rankin - glc 13:48:06 02/2/04 (8)

Some things to check - Gordon Rankin 07:54:42 02/3/04 (7)

Re: Some things to check-my answers - glc 14:19:17 02/3/04 (6)

Re: Some things to check-my answers - Gordon Rankin 09:36:51 02/4/04 (5)

Re: New test suggested from GR - glc 02/4/0414:03:21 02/4/04 (4)

Ideas - Gordon Rankin 07:47:42 02/5/04 (3)

Re: Ideas-very appreciated. - glc 14:43:01 02/5/04 (2)

your welcome - Gordon Rankin 06:26:35 02/6/04 (1)

Re: Gordon: incredibile results with Hytron VT52! - glc 10:04:39 02/6/04 (0)

Re: Few suggestions - glc 12:44:18 02/2/04 (2)

Re: Few suggestions - Gordon Rankin 08:00:45 02/3/04 (1)

Re: Few suggestions- I received! - glc 14:26:54 02/3/04 (0)

Re: SET VT52 amplifier; 12-14mV hum noise is too high? - Trtiode Kingdon 15:23:31 02/1/04 (3)

Re: SET VT52 amplifier; 12-14mV hum noise is too high? - glc 13:41:48 02/2/04 (2)

What is the value of "A ajuster" ? (nt) - Triode Kingdon 17:56:41 02/2/04 (1)

Re: What is the value of "A ajuster" ? (nt) - glc 14:38:31 02/3/04 (0)

Been there, hated it ... :^) - Paul Joppa 11:29:56 02/1/04 (1)

Re: Been there, hated it ... :^) - glc 13:16:02 02/2/04 (0)

Does the noise bother you? - Chris O 10:34:04 02/1/04 (0)

Follow Ups

Re: New test suggested from GR - glc 02/4/0414:03:21 02/4/04 (4)

Ideas - Gordon Rankin 07:47:42 02/5/04 (3)

Re: Ideas-very appreciated. - glc 14:43:01 02/5/04 (2)

your welcome - Gordon Rankin 06:26:35 02/6/04 (1)

Re: Gordon: incredibile results with Hytron VT52! - glc 10:04:39 02/6/04 (0)

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