LFOs different approach


Well-known member

I have build a quite big polyphonic synth with many oscillators, and 3 LFOs. The patch is quite complicated with many cords.
To simplify the patch and the code, I tried a new approach for the LFOs section. My idea is to read the amplitude of my LFOs as fast as possible (2.9ms) with the Peak object, and use the result to modulate the oscillators parameters within the sketch. For polyphonic synths, I find it easier.

Do you think it is a valid solution ?
The audio lib is updated every 2.9ms. Is it fast enough to modulate smoothly oscillators pitch, shape, amplitude ? and filters FC ? My first tests seem to be OK except for amplitude modulation (little clicks).
Thanks for any advice.

You'll not be able to eliminate the clicks at 344Hz going this route, you'll be introducing these artifacts across the whole spectrum at every multiple of 344Hz, so I'd be pessimistic about this particularly for frequencu or amplitude modulation.

Which Teensy are you using - is throughput an issue?
Thank you Mark.
Frequency modulation sounds OK up to 20hz. Enough for LFO.
Amplitude doesn't sound OK, as you mentioned.
What do you mean by throughput ?

I use a T4.0.
If you use T4 throughput is not normally an issue, so just do everything in audio objects, you won't run out of CPU easily, many 100 audio objects can coexist on a 600MHz dual issue machine, there's upto 27000 instructions per sample time available and the Audio lib is carefully optimized.