Hallo, hard off hat gesagt: // hard off wrote:
most of the stuff that operator synth does looks fairly straight-forward, shouldn't be too hard to put together a basic pd clone.
I had a quick look at the Live manual, where I found, that Operator is just a 4-op FM synth with some additional tweaks. A simple 4-op FM is on my January TODO list for the RjDj library anyway. In general FM is easy, but the more operators you have, the more you want to use [mtx_mul~] from Iemmatrix, but RjDj only has vanilla objects.
challenging bits will be the square and saw waves with variable numbers of partials, but i think that will probably just be a case of [tabosc4~] and making some tables with sinesum values.
Or some summation formulas, but tabosc4~ is easier.
then that knob to alter the amount of aliasing, it could be using upsampling and then lowpass filtering like the nord synths do, or like the 'classic synth' example in pd's audio documentation. but that approach quickly eats up cpu....or else it could be using an adjustable bandlimiter, something like the [blosc~ comparator] external, but with adjustability. actually, this function is the hardest one for me to think of a solution for.
Yep, aliasing in FM always is tricky. It will be ignored for RjDj. ;(
the filters shouldn't be TOO hard, although to get a good lowpass, notch, bandpass and highpass it might be best to dig through pd-extended's externals. for lowpass i usually use [resofilt~] bandpass vanilla's [vcf~] is fine, although franks new resonz~ / resonr~ filters look super promising. for highpass, i prefer [svf~ high]. not sure about the notch filter.
I'm a bit proud of resonz~ and resonr~: In the end they look very simple, the hard part was digging J.O. Smith's Filter book. ;) I'll also do some version with signal inlets later.
If anyone knows which transfer function would make a good 2 pole resonant lowpass filter (like lp2~ in Iemlib) I'd be super thankful.
Ciao
Frank Barknecht