Trimpot codes / PWM only half working.

[bobbletrox]

So...I just perfed a PWM using trimpots for the volume and pulse width controls -it works- but there seems to be a small problem.  It produces the "squeezed" tone fine at one end of the pulse width trimpot's range, but at the other end of the range, the PWM just produces a very quiet overdrive sound.  Nothing really happens until the trimmer is cranked all the way and the squeezed tone comes through.  Btw, the volume trimpot works fine.

I'm just wondering whether I'm using the right value trimpots!  I coulda picked up the 10c ones with the value written on them but oh no I had to go for the plastic housed ones with the wierd codes.

These are the codes on the trimpots:
Pulse Width: Z1026  (supposed to be 500k)
Volume: Y104B (supposed to be 100k)

Any help would be appreciated  

[Peter Snowberg]

These are the codes on the trimpots:
Pulse Width: Z1026  (supposed to be 500k)
Volume: Y104B (supposed to be 100k)

The 104 on the volume pot looks fine (10 + 4 zeros = 100000 ohms) but looking at those numbers I would guess that the pulse width pot is actually 1K (10 + 2 zeros).

If unsure, it's always best to read the real value with your DMM.

Best of luck,
-Peter

[bobbletrox]

Thanks Peter!  I went to the store after reading your reply and bought the right trimpot.  I looked at the 1K'ers and sure enough, that's what I had.  Even the store guy got confused and told me that the 500k I was buying was a 5k!  Nevertheless, the PWM works great now -in all it's potentially ear splitting glory.  It produces some great Microsynth-esque lead tones through an overdriven amp!  I'm gonna give the LFO a go now.

[Peter Snowberg]

Cool! Happy to help.

Take care,
-Peter