After my AD815 / Starfish experiment, I've been rebuilding my preamp. The incumbent AD815 is now gone, and the Starfish is making its way into the case. Part of the project, just as nickcase is doing, will be to put a Jos van Eindhoven remote-controlled attenuator between the 729 and 321 circuits.
One thing about the AD815 I really liked was the lack of coupling caps (ie. 1 per channel in the preamp). The Starfish currently has 4 per channel, something I'd like to reduce, hence this thread.
My ideas are to:
1. Remove the input coupling caps and replace them with wire links. This shouldn't be a problem in my specific case, because I know my source has output coupling caps.
2. Remove the 729 output and 321 input coupling caps. I'll be removing the pot and replacing it with a relay-switched stepped attenuator that can accommodate a DC potential across is. The question here is: what happens when the DC potentials of the 729/321 circuits combine? Bad things? Nothing? I don't know the answer to this one. At the very least, I can remove either (a) the 729 output, or (b) 321 input cap. If removing both is a non-starter, then is either a "better" candidate for removal?
3. Replace the 321 output caps with good polyprops.
Any other suggestions for reducing the coupling cap count?
Carl
One thing about the AD815 I really liked was the lack of coupling caps (ie. 1 per channel in the preamp). The Starfish currently has 4 per channel, something I'd like to reduce, hence this thread.
My ideas are to:
1. Remove the input coupling caps and replace them with wire links. This shouldn't be a problem in my specific case, because I know my source has output coupling caps.
2. Remove the 729 output and 321 input coupling caps. I'll be removing the pot and replacing it with a relay-switched stepped attenuator that can accommodate a DC potential across is. The question here is: what happens when the DC potentials of the 729/321 circuits combine? Bad things? Nothing? I don't know the answer to this one. At the very least, I can remove either (a) the 729 output, or (b) 321 input cap. If removing both is a non-starter, then is either a "better" candidate for removal?
3. Replace the 321 output caps with good polyprops.
Any other suggestions for reducing the coupling cap count?
Carl