Problem with vowel waveform (edit: fixed!)

Hi all, hope this is the right category for this…

I’ve just had my first serious play with the vowel voice on my Shruthi-1, but if I set the “Param” function to 96 and above it suddenly gets really crackly (think Geiger counter!). Below 96 it’s perfect and all the other waveforms are working as they should too. I’ve turned off everything in the mod. matrix and even tried turning off the MIDI out. I have a quiet linear PSU, but as every other waveform sounds great I don’t think it’s signal path. I’ve recorded some samples and taken a look at 'em in my audio editor and there seem to be short spikes and longer discontinuities. If I loop a clean part between the discontinuities it sounds perfect. The crackles happen all the way across the keyboard but behave differently with different notes.

Some pics of a wave (if I can figure out how to show pics here!)

An entire note sample.

A short spike.

A bigger bit of strangeness.

Does anyone else get this? Have I broken something? My Shruthi’s on v0.91 firmware btw.

Thanks in advance. :slight_smile:

This is not a bug, this is a feature!

If you use the step sequencer to control param, you’ll find that the values above 96 (displayed as e or f on the step sequencer), when played for the duration of a step, make a good percussive noise. If the sequence is played fast enough they sound like consonants.

So when param is above 96 the vowel generator turns into a weirdly filtered noise generator ; and your observation about the sound losing its “pitchiness” quality is correct.

Aha, so I haven’t broken anything then!

That’s cool, btw I’m using Bidule to create a keyboard split: left hand for melody, right hand undergoes note to cc conversion and controls waveform param. “Woo-woo, wah-wah, wow!” Now for those consonants…

Thankyou for the super-swift reply too. :slight_smile: