Hey guys, delighted to tell you that my Mono/Poly is full healthy! For the time being that is... All voices are stable and in tune.

I had it powered on all day today, twiddling about to check over the parameters and what not.  I had let it sit powered on for a few hours only to come back to it with the filter resonance not working.  It only just increases the output level, basically just makes it louder. Regardless of settings, unison, poly, etc.

It was working great and then all of a sudden, no resonance, but it just increases the output level. The rest of the filter works fine. Very strange... 

Does anyone have any thoughts or ideas of what this could be caused from  

I was so happy to have it back after its three month stay with my tech, only now to have another issue...

Any thoughts, hints, tips or tricks would be much appreciated...