In Reply to: non-inverting preamp w/schematic ... posted by deathtube 667 on June 15, 2017 at 16:57:41:
I appreciate the concept that what comes out of a preamp is exactly what goes in. IMO, that should include the input-output phase relationship. The two-tube circuit you posted is a variation of the "Blue Velvet" preamp, and it's a design I've been considering and analyzing for a long time. However, if additional system gain isn't needed, a cathode follower will provide much greater bandwidth, lower distortion and more substantial driving ability. A follower done right will also be sonically transparent, a characteristic that's difficult to achieve using common cathode stages. A zero-gain preamp has another potential advantage. The less gain the preamp exhibits, the more clockwise the input potentiometer will be set in normal operation. That means less carbon track in series with the signal path and a higher resistance (less signal current) to ground. All this adds up to less invasive control and a greater likelihood signal integrity won't be compromised.
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Follow Ups
- RE: non-inverting preamp w/schematic ... - Triode_Kingdom 11:08:09 06/17/17 (7)
- RE: non-inverting preamp w/schematic ... - edgilfus 18:58:58 06/19/17 (1)
- RE: non-inverting preamp w/follower schematic... - deathtube 667 06:55:08 06/20/17 (0)
- RE: non-inverting preamp w/schematic ... - cpotl 05:34:26 06/19/17 (0)
- RE: non-inverting preamp w/schematic ver. 2 - deathtube 667 07:41:59 06/18/17 (3)
- RE: non-inverting preamp w/schematic ver. 2 - deafbykhorns 15:26:43 06/18/17 (2)
- RE: non-inverting preamp w/schematic ver. 2 - deathtube 667 17:49:47 06/19/17 (0)
- RE: non-inverting preamp w/schematic ver. 2 - dave slagle 20:07:07 06/18/17 (0)