My Korg FK 1 VCF pedal.

[Simon Barden]

It's hiss. It's a lot louder when the 4-pole filter is selected compared to the 2-pole. It's independent of any input signal. Had a look inside but there's nothing obvious. Only a few small electrolytic caps on an otherwise SM board and they look fine. It's almost as loud as the guitar signal in 4-pole mode, not at all background. I need to try it into a line input again instead of my guitar amp, as I don't recall it being noisy when I was feeding my Korg Odyssey synth through it.

[DrNomis_44]

It's hiss. It's a lot louder when the 4-pole filter is selected compared to the 2-pole. It's independent of any input signal. Had a look inside but there's nothing obvious. Only a few small electrolytic caps on an otherwise SM board and they look fine. It's almost as loud as the guitar signal in 4-pole mode, not at all background. I need to try it into a line input again instead of my guitar amp, as I don't recall it being noisy when I was feeding my Korg Odyssey synth through it.

You could try swapping out the resistors for metal film types if the originals are mostly carbon film types, doing that might reduce the hiss noise a bit, you might need to trace through the signal path with either an audio probe or a scope to find out where the hiss noise is coming from, I'm going to record a demo of my Korg FK 1 shortly, just having my daily coffee fix at the moment.


Update:


Here we go, here's a quick demo recording of my Korg FK-1 VCF pedal, this is really just to give you an idea what it sounds like:

https://dl.dropboxusercontent.com/u/...VCF%20Demo.mp3