Another Tim Escobedo's PWM -thread

[Jebus]

Hey!

I've been looking for building a Tim Escobedo's PWM for some time now. So today I wanted something to do for the evening and stopped by the local electronics store and bought a 40106 and a 386.

Got home, googled for nice vero layout and found this: https://dl.dropboxusercontent.com/u/7464107/pwm1.jpg

Gathered all the parts and got the veroboard together. But now I have couple questions:

1) Somebody posted that if you want a on/off -switch for the LFO, you can put it to ground pin 13 on 40106. But on that board pin 13 is already grounded. So should the switch actually lift pin 13 from ground instead?

2) I thought I had more potentiometers at home, but I only found one 500kB. Can I substitute one with a 250kB? Which one? Or is it better to use a 500kA instead?

Thanks!

[nocentelli]

Pin 13 is grounded on the stock pwm circuit along with all the other unused inputs to reduce current consumption. The suggested LFO however uses the pin 13/12 inverter as the LFO, so you need to ungrounded it, and connect it to ground via the 2u2 cap and add the other parts in the EZ LFO snippet so the then charges and discharges to ground, producing the oscillation through the depth pot and transistor to vary the pwm effect.

[Jebus]

Pin 13 is grounded on the stock pwm circuit along with all the other unused inputs to reduce current consumption. The suggested LFO however uses the pin 13/12 inverter as the LFO, so you need to ungrounded it, and connect it to ground via the 2u2 cap and add the other parts in the EZ LFO snippet so the then charges and discharges to ground, producing the oscillation through the depth pot and transistor to vary the pwm effect.

Alright, thanks a lot! That clears it out. Any idea about the potentiometers?

[blackieNYC]

Try the 250 k pot on its own, and try it with a 250k resistor.  Or maybe a 100k. If memory serves, It's a broad range of sounds on that pot and you'll probably find your favorite range in there somewhere. If you find you like the 500k sound and the 10k setting's sound, you'll just have to get yourself the 500k pot.