Modded GE7 has turned hissy again - help please?

bacchanalian

I changed the chips and three capacitors in a GE7 and there was a huge improvement in the level of noise.  I only tried it as I was sceptical about some of the online demos, but it really did work.  I am a novice solderer but seemed to manage OK.

However, the pedal seems to have developed some noise.  A small boost on 1.6k and 3.2k has become noisier.
Does anyone know if this is due to some wonky soldering or maybe one of the replacement components has blown.
Maybe it is a case of trial and error on each of the new components.

Any advice welcome

bacchanalian

Bump for any advice welcome
I am getting hissed off with this mod gone wrong

ICBM

Did you keep the old components? If so, try re-substituting them one at a time. Whatever is causing it will only be one part.

bacchanalian

Thank you @ICBM ;
 
Unfortunately, I did not keep the old components. 
However, it would be cheap to buy the same components and try replacing them. It should be very simple for the chips as the kit I first used replace the original chips with sockets. Unless it is some wonky soldering around the socket pins.

Thanks for the tip 

ICBM

That's good, it makes things very easy. Chances are it's just the chip that operates the 1.6 and 3.2k filters - IC1 according to the schematic - change that first.

An interesting feature of the circuit is that with the original chips *all* the frequencies hiss when you move the slider up or down away from flat... so as a quick test you could try swapping IC1 for IC2 or 3 and see if the problem moves.

bacchanalian

Brilliant thanks, I will try that later today.