RE: impedence of CCS mu output

Posted by Mike C (A) on April 12, 2010 at 12:34:59

In Reply to: RE: impedence of CCS mu output posted by Michael Koster on April 7, 2010 at 22:56:52:

Hi Michael,
I like the look of this unit a lot, even though I don't really understand the solid state parts.
I also use active loads giving low Zout, which can then drive a low impedance RIAA (low series resistance) very well indeed as you mention.

What's more, you can drive the next stage 'through' the RIAA very well. The grid resistor of the second stage, and the impedance of its miller capacitance, will be *much* larger than the RIAA series resistor so they will be no problem to drive.

I have built several phono stages and this approach (low Zout active stages and low R RIAA) gives me the best results. You should do well.

I will pass on a relevant experience ... just a thought.
One unit of mine uses a first stage of a D3a with a simple resistor anode load; it sounded good. But I then built a very similar unit; almost identical PSU, identical RIAA, and identical second stage (6072 with E83F load). For the first stage I used a 6AN4 triode with E83F pentode load.
So this gave a direct comparison between D3a trioded (R load) and 6AN4 (active load). The 6AN4 was far superior; it was not a subtle difference! More musical, better tonality, better dynamics and drive ... just better all round. How much was due to 6AN4 vs D3a, and how much due to the active load, I cannot say; but the 6AN4 is a peach of a valve (as someone here said) and you might want to try it instead of the D3a?

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Follow Ups Full Thread

Topic - impedence of CCS mu output - bobbyj 16:55:01 04/7/10 (27)

RE: impedence of CCS mu output - VT4C211 17:26:36 04/11/10 (4)

RE: impedence of CCS mu output - dave slagle 21:18:39 04/11/10 (3)

RE: impedence of CCS mu output - VT4C211 21:29:48 04/12/10 (2)

RE: impedence of CCS mu output - Michael Koster 23:50:46 04/12/10 (1)

RE: impedence of CCS mu output - VT4C211 19:01:53 04/15/10 (0)

RE: impedence of CCS mu output - Michael Koster 22:56:52 04/7/10 (13)

RE: impedence of CCS mu output - Mike C 04/12/1012:34:59 04/12/10 (1)

RE: impedence of CCS mu output - Michael Koster 10:14:57 04/14/10 (0)

RE: impedence of CCS mu output - bobbyj 11:22:37 04/8/10 (3)

RE: impedence of CCS mu output - Michael Koster 12:57:26 04/8/10 (2)

RE: impedence of CCS mu output - Satanpatiently 14:33:37 04/8/10 (1)

RE: impedence of CCS mu output - Michael Koster 08:02:47 04/9/10 (0)

Thank you for that great explanation. nt - Tre' 10:14:22 04/8/10 (0)

Michael, to split hairs... - Allen Wright 06:13:59 04/8/10 (1)

RE: Michael, to split hairs... - Michael Koster 08:11:19 04/8/10 (0)

RE: impedence of CCS mu output - Joao 23:52:51 04/7/10 (3)

RE: impedence of CCS mu output - Michael Koster 10:06:33 04/8/10 (2)

RE: impedence of CCS mu output - reVintage 05:19:52 04/10/10 (1)

RE: impedence of CCS mu output - Michael Koster 08:24:29 04/10/10 (0)

RE: impedence of CCS mu output - Tre' 17:04:47 04/7/10 (7)

RE: impedence of CCS mu output - bobbyj 18:24:37 04/7/10 (6)

RE: impedence of CCS mu output - Tre' 18:57:48 04/7/10 (5)

RE: impedence of CCS mu output - bobbyj 20:18:13 04/7/10 (3)

RE: impedence of CCS mu output - Tre' 20:40:39 04/7/10 (2)

RE: impedence of CCS mu output - bobbyj 10:15:02 04/8/10 (1)

RE: impedence of CCS mu output - Tre' 10:20:13 04/8/10 (0)

Here's a helpful calculator - Tre' 19:02:17 04/7/10 (0)

Follow Ups

RE: impedence of CCS mu output - Mike C 04/12/1012:34:59 04/12/10 (1)

RE: impedence of CCS mu output - Michael Koster 10:14:57 04/14/10 (0)

RE: impedence of CCS mu output

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