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PWM knob behaviour

PWM knob behaviour
« on: October 05, 2021, 12:14:03 AM »
Quick question, is the pulse width knob supposed to yield either 0% or 100% duty cycle at either the upper or lower end of its travel? I seem to be getting some voices that stop sounding and some that donít.

Re: PWM knob behaviour
« Reply #1 on: October 05, 2021, 07:10:40 AM »
Yes, that's normal for Dave Smith's synthesizers, and it's a useful sound design capability.
"Simplicity, simplicity, simplicity!"

- Henry David Thoreau

The Musical Synthesizer YouTube Channel:
https://www.youtube.com/channel/UChLGwGiRVs7rlZXnOG9_mUw

The Musical Synthesizer Blog: https://themusicalsynthesizer.wordpress.com

Re: PWM knob behaviour
« Reply #2 on: October 06, 2021, 01:14:51 AM »
Yes, that's normal for Dave Smith's synthesizers, and it's a useful sound design capability.

Thanks for your reply, though it is a little ambiguous.

Do you mean itís normal for pulse width to go through zero, and hence completely silent? (Mine doesnít.)

Or do you mean that itís normal for not all voices to go silent as happens on mine?

Iíve actually noticed some odd inconsistencies between the oscillators when pulse width is set to 0:

Oscillator 1 pulse width/volume varies quite a bit from voice to voice, whereas on oscillator 2 is very consistent.

Thereís also a noticeable jump between voice boards. On oscillator 1, itís slightly harder to spot as the voices all sound at different volumes anyway, but on oscillator 2 I get five voices at one consistent loudness, five at another.

I have opened a ticket in this as Iím not sure if this is a software or hardware thing.


Re: PWM knob behaviour
« Reply #3 on: October 06, 2021, 12:02:21 PM »
Do you mean itís normal for pulse width to go through zero, and hence completely silent (Mine doesnít.)?  Or do you mean that itís normal for not all voices to go silent as happens on mine?

I mean the former.  There can be slight variations in the degree to which individual voices are affected by pulse width modulation, but your case seems to be too extreme.  I'm presuming the pulse width of all the voices is being modulated by a single LFO. 

Have you tried re-calibrating the filters and oscillators?  It's always the best place to begin.
"Simplicity, simplicity, simplicity!"

- Henry David Thoreau

The Musical Synthesizer YouTube Channel:
https://www.youtube.com/channel/UChLGwGiRVs7rlZXnOG9_mUw

The Musical Synthesizer Blog: https://themusicalsynthesizer.wordpress.com

Re: PWM knob behaviour
« Reply #4 on: October 07, 2021, 03:32:55 AM »
Got a reply from Mark at Sequential and they are seeing the same behaviour and it has gone on the list of stuff to fix.

Re: PWM knob behaviour
« Reply #5 on: October 07, 2021, 11:47:41 AM »
Excellent.  I'm glad you moved this from the forum to Sequential Support.
"Simplicity, simplicity, simplicity!"

- Henry David Thoreau

The Musical Synthesizer YouTube Channel:
https://www.youtube.com/channel/UChLGwGiRVs7rlZXnOG9_mUw

The Musical Synthesizer Blog: https://themusicalsynthesizer.wordpress.com

Re: PWM knob behaviour
« Reply #6 on: October 07, 2021, 11:56:36 AM »
Excellent.  I'm glad you moved this from the forum to Sequential Support.

I usually do both fairly quickly as I know many people donít. There were a fair few fixes in the last updates to things I reported so guess itís always worth doing, even if sometimes what Iím reporting might be nothing.