x0x-heart PWM

by lis0r » Tue Sep 15, 2015 15:52 UTC

Hi,

I'm eagerly awaiting delivery of my x0x-heart boards, with the intention of building a completely digitally controlled 4 channel monster, with integrated RAT clone distortion.

Given this architecture I'm interested in using PWM to drive as much as possible. What clock rate is recommended for the PWM driver?

I notice that the resonance control doesn't have a PWM input. Is there any reason I couldn't use a
CD40109 controlling two switches of a CD4066 to provide PWM controllable resonance? Does C13 spoil this? Would digipots work instead?

Thanks!

Lisa

Re: x0x-heart PWM

by guest » Tue Sep 15, 2015 19:53 UTC

awesome project, i look forward to hearing it when youre done.

i would recommend 40kHz or higher for the PWM. the pacemaker board uses 80kHz. but, at some point you are limited by how fast the switches can turn on and off for the minimal pulse width. for the resonance you can use either switches or digipots.