No volume output with square shape on OSC 1 & 2

[slamelza]

Hi all,

New to the forum and just picked up a Prophet 06 Module running OS 1.4.0. Today, when I was fooling around with a blank patch I did the following to produce no output:

1. Oscillator 1 turned up 100% in the mixer section
2. Changed to square
3. Changed my pulse width from 0% and 100%. At 0% I hear no output, and at 100% I hear no output.

This is the same for Oscillator 2:

1. Oscillator 2 turned up 100% in the mixer section
2. Changed to square
3. Changed my pulse width from 0% and 100%. At 0% I hear no output, and at 100% I hear no output.

I believe it happens with the triangle shape too, but cannot confirm since I am at work now.

Do I have a defective unit or is this normal?

Thanks in advance!

[abstrx]

Yep, that's expected. Since square waves are pulsing between 0 and 100, instead of fading like a sine or triangle, if you set PW at full on or off there's no signal coming from that OSC. If you turn it up or down a few % you'll hear it again. In the very narrow PW, ~2-5%, you might need to boost the OSC mix level to compensate.

Good stuff to keep in mind when you use PWM, too.  If it modulates to either 0% or 100% at a slow rate that OSC will drop out for part of the mod cycle. But that allows for cool PWM tones at higher rates, so it's a good option to have when used intentionally - or by a happy accident!

[abstrx]

Related PW topic - with helpful gif
http://forum.davesmithinstruments.com/index.php/topic,278.msg2904.html#msg2904

[slamelza]

Yep, that's expected. Since square waves are pulsing between 0 and 100, instead of fading like a sine or triangle, if you set PW at full on or off there's no signal coming from that OSC. If you turn it up or down a few % you'll hear it again. In the very narrow PW, ~2-5%, you might need to boost the OSC mix level to compensate.

Good stuff to keep in mind when you use PWM, too.  If it modulates to either 0% or 100% at a slow rate that OSC will drop out for part of the mod cycle. But that allows for cool PWM tones at higher rates, so it's a good option to have when used intentionally - or by a happy accident!

I appreciate the response!

[slamelza]

Related PW topic - with helpful gif
http://forum.davesmithinstruments.com/index.php/topic,278.msg2904.html#msg2904

Helpful animation! Thanks dood!

[abstrx]

np! shout out to mr Paul Dither for posting the gif

[abstrx]

sort of on topic
https://www.reddit.com/r/synthesizers/comments/63mfo5/nick_batt_is_mad_for_pwm/