Hydra FV-1 pin 1 and 28 voltage

[ttango]

Question. What should the voltage be going in pin 1 and coming out pin 28 be on the FV-1 chip?
I'm getting 1.7ish

https://docs.pedalpcb.com/project/Schematic-Hydra.jpg

 

[Cybercow]

Considering the FV-1 runs on +3.3V, a +1.7V DC reading on the in and out pins of the FV-1 seems right - it's ~½ the supply the voltage for that chip for DC offset. Note that C3 (input side) and C8 (output side) block the DC reference from the rest of the +9V supplied sections of the circuit.

Out of curiosity, why the concern of the FV-1 in/out DC voltages?

 

[ttango]

The volume drop when it is engaged. My reading of the data sheet for the FV-1 made me think that it had to be min of 2.5. But the volume drop could be from somewhere else.

 

[phi1]

is the volume drop on the dry signal, which doesn’t go through the fv-1?

There are spots where it’d be easy to add boost by subbing a resistor, though it shouldn’t be needed since I believe the volume pot should go past unity volume.

 

[ttango]

Actually, the FV-1 wasn't working when I last tested it with the guitar. Cold solder on a cap. I will test it tomorrow as I know get signal through the FV-1.