Revisiting the Yusynth VC Panner

[kkissinger]

I built this circuit back in 2010 and have used it regularly since then.

However, I never could really get the pan pots or Voltage Controlled panning to work smoothly. Over the years I've tried various fixes to no avail.

I've just worked around the issues over the years. Well, today I decided I would fix this once and for all. After all, I'd rather spend time with creative music-making than working around technical issues.

The symptoms were that when the pan-pot was in the center position, the sound wasn't centered. Also, the Voltage Controlled panning was not very effective. I was unable to adjust the trimmers for any great improvement.

I decided today that I simply MUST have used a incorrect resistor value and I didn't find an incorrect value. However -- by golly -- I discovered that on each of the four panners, I had switched the leads from the panpots and the panpot control-voltage attenuator! Though both circuits feed the same op-amp mixer, they do it through different resistor values! No wonder it "worked-but-not-very-well"!

Well, it was an easy fix to switch the leads to their proper positions and now the Voltage controlled panners work to spec!

Kind of nice after 13 years!

My experience with DIY has shown me that problems are not usually anything very exotic and, rather, they are blunders such as cold solder joints or mis-routed leads from the front panel to the PCB.

The Yusynth modules that I have built continue to function beautifully and I am very thankful to Yves Usson for so generously sharing his designs.

[RingMad]

Ha, nice story, thanks for sharing.

And it's this kind of thing that one asks oneself "Why didn't I do this so much earlier?!" But that's just life.

Indeed, I think an important part of debugging electronics (or anything) is to be willing to accept that the problem could be due to one's own (simple) mistake.

BTW, I am currently re-listening to your excellent performance for the September equinox concert.

[kkissinger]