Goldpoint Stepped Attenuator

[roycruz23]

Hi! I planned on running S.E.X. 3.0 (mainly as headphone amp) with my
Hagerman Clarinet 2 DIY preamp upgraded with Goldpoint stepped attenuator.
Is there gonna be sonic improvement if I upgrade S.E.X. 3.0’s volume pot to
Goldpoint?

Thank you,
Roy

[kgoss]

If you turn the S.E.X. amp’s volume all the way up it is essentially removed from the circuit. I would start that way and use your preamp volume. If you find the S.E.X. amp is being overdriven you can turn the amps volume down to the point of no longer clipping with the preamp volume at 100%. You might want to replace the volume control if that is the case, or if you always have a preamp in front of it the volume can be replaced with a pair of resistors.

[roycruz23]

Please educate me about "essentially removing from the circuit", isn't it set to "Max volume" if I turn SEX's amp volume all the way up?
 

[kgoss]

I’ll take a swing at it and rely on the Bottlehead team to correct anything I have wrong.

I have an earlier version of the amp but I believe the kit came with a 100K potentiometer. At zero volume it adds 100 Kohm resistance to the incoming signal. At max volume it adds zero ohms so the full input signal is sent to the input stage of the amp.  Signal still flows through the potentiometer so it’s not really out of the circuit but it’s not attenuating the source.

[Paul Birkeland]

Well, you need a resistor from grid to ground on each channel of the SEX to keep the first stage grids grounded.

If you take the pot out, you need a pair of 100K resistors from input to ground.  If you turn the pot all the way up, that does the exact same thing.