470k R21 after volume control in Friedman circuits?

[harmaes]

I just build a Complex overdrive and today finalized a Tempest from Aion which is a BE/DS hybrid.
I noticed that the Tempest volume control behaved strangely, in the very upper range the sound changed and the output volume was lower than the Complex OD. I just inspected all components of the Tempest build again and noticed that the resistor I got delivered (R21 in the PedalPCB schematics) was a 470R instead of 470k!
I will replace the resistor tomorrow but I’m curious what the 470k does in the circuits? Am I correct that this has an influence on the output and behavior of the volume pot?

 

[BuddytheReow]

Hmm. Can you post a schematic?

Edit: if you’re referring to r21 in the complex OD it is used to bias the IC3 and effectively turn it on. The MID control happens here and is an active EQ so the opamp is needed. Sorry, I though you were talking about the Aion board

 

[harmaes]

Here’s the document that includes the schematic: https://aionfx.com/app/files/docs/tempest_documentation.pdf

The 470k resistor is after the volume and before the mid control. I can imagine that a 470R here would behave differently?

 

[harmaes]

I replaced the 470 resistor with a 470k and the issues are solved. Volume is unity just below half way now and the strange mid increase in the upper half of the volume pot have been solved. Probably the opamp for the mids didn’t bias correctly without the 470k?

 

[BuddytheReow]

Probably the opamp for the mids didn’t bias correctly without the 470k?

Bingo.