Re: Sound Labs

Posted by Lew (A) on July 2, 2002 at 14:20:13

In Reply to: Re: Sound Labs posted by Roy on July 2, 2002 at 13:39:52:

I was fortunate enough to get a couple of dozen of 2uF polystyrenes from Southern Electronics off their "last run" of them. I will use same in the M1s. My amps are essentially MA2s with six 6C33C output tubes per chassis instead of twenty (?) 6AS7s, as per the MA2 spec. Thus I have a little less power than an MA2 but a little more power than a standard MA1. The current configuration includes type 6900 tubes as input voltage amplifier (in the standard Atma dual-differential cascode topology) running 11 to 12 mA of current. The CCS for this circuit uses an ECC99, stacking the two sections in cascode mode. This input circuit feeds three discrete CFs per chassis, such that each CF tube drives only one pair of 6C33Cs, one section per output tube. (Coupling caps are Rel teflon.) This enables me to set bias current separately for each output tube. The CFs are made from 12SX7s. Then each 12SX7 CF section has its own CCS, made from a single section of an ECC99. I have now acquired just about enough 7241s to replace all the 6C33Cs in both chassis', if I should require a big boost in power to supra MA2 levels. I am loathe to convert the amps, however, because the 6C33Cs have been so reliable. The power supplies have the usual hexfreds, lots of capacitance, pi filters, separate LC isolation networks for the plus and minus supplies to the driver stage and for the bias supply. I am only sorry that I have no room left to install the constant voltage sources that would constitute the upper half of the full SLCF config.

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Follow Ups Full Thread

Topic - Mark... do you have some spare time now? - Luis 03:35:17 06/19/02 (22)

How's this? - mark 07:58:21 06/19/02 (21)

Perfect, thanks.... but... - Luis 05:48:30 06/26/02 (20)

Re: Perfect, thanks.... but... - mark 07:22:00 06/26/02 (19)

Re: Perfect, thanks.... but... - Lew 13:21:22 06/26/02 (18)

We're all crazy, I hope - mark 14:31:37 06/26/02 (17)

Re: We're all crazy, I hope - Lew 06:48:31 06/27/02 (16)

Re: We're all crazy, I hope - mark 20:14:46 06/27/02 (15)

Haven't survived very well. - Lew 07:10:35 06/28/02 (14)

Re: Haven't survived very well. - Roy 02:57:11 06/29/02 (13)

Sound Labs - Lew 06:55:36 07/01/02 (12)

Re: Sound Labs - Roy 14:16:01 07/01/02 (11)

Re: Sound Labs - Lew 14:39:08 07/01/02 (0)

Re: Sound Labs - Lew 14:36:32 07/01/02 (9)

Re: Sound Labs - Roy 01:34:39 07/02/02 (8)

Re: Sound Labs - Lew 06:55:49 07/02/02 (7)

Re: Sound Labs - Roy 13:39:52 07/02/02 (6)

Re: Sound Labs - Lew 14:20:13 07/02/02 (5)

Re: Sound Labs - Roy 16:13:56 07/02/02 (4)

Re: Sound Labs - Lew 07:41:54 07/03/02 (3)

Re: Sound Labs - Roy 16:48:25 07/03/02 (2)

Re: Sound Labs - Lew 07:01:06 07/05/02 (1)

Re:Sound Labs - Roy 15:08:05 07/05/02 (0)

Follow Ups

Re: Sound Labs - Lew 14:20:13 07/02/02 (5)

Re: Sound Labs - Roy 16:13:56 07/02/02 (4)

Re: Sound Labs - Lew 07:41:54 07/03/02 (3)

Re: Sound Labs - Roy 16:48:25 07/03/02 (2)

Re: Sound Labs - Lew 07:01:06 07/05/02 (1)

Re:Sound Labs - Roy 15:08:05 07/05/02 (0)

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