Cgs synth

I've now wired up two identical CGS VCOs and am having identical issues with both of them.
1. The initial pulse width knob does nothing. I have a 100k linear pot with T1 connected to -VE, wiper to PWM, and T2 connected to +VE. The PWM input works exactly as expected.
2. The sub pulse output sounds like the pulse width is about 5%. This might be normal, but with the lack of demos out there, I'm just not sure.
3. The difference between the "sine" and the ramp when I turn the knob is pretty minimal, although this might also be normal. I get more variation using a mod source, but even then it never quite gets all the way to either shape.
Any help you guys can give is much appreciated.

> 1. The initial pulse width knob does nothing. I have a 100k linear pot

with T1 connected to -VE, wiper to PWM, and T2 connected to +VE. The PWM
input works exactly as expected.

Bridge the input pad to the resistor. It looks like a track has gone
missing. (Practically invisible!) The artwork is correct, so I don't know
how it happened!

> 2. The sub pulse output sounds like the pulse width is about 5%. This

might be normal, but with the lack of demos out there, I'm just not sure.

It's the staircase reset pulse, so it will be very narrow.

> 3. The difference between the "sine" and the ramp when I turn the knob is

pretty minimal, although this might also be normal. I get more variation
using a mod source, but even then it never quite gets all the way to either
shape.

Reduce the 4M7 input resistor to a value you are happy with.

Ken

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Ken Stone sasami@... otherunicorn@...
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