http://map.grauw.nl/resources/sound/yamaha_ymf262.pdf page 12: feedback denotes the feedback (self-modulation) of the first operator, cnt denotes the connection type (additive or phase-modulated synthesis). Or (simplified): int16_t channelOutput = m_operators[0]->nextSample(feedback()); pushFeedback …

The core identity used is: sin(x)/alpha = exp(ln(sin(x)/alpha)) = exp(ln(sin(x)) - ln(alpha)). Remember that the sinLog table is stored negated, thus it's effectively (with exp'(x) = exp(-x)): exp'(-ln(sin(x)) + ln(alpha))). With ln(alpha) = env, this is pretty much how to to do it.

I'm not sure what happens here, but if I manually set the BLK value everywhere to 6, I get the expected output for the bass drum (it even looks nearly similar when comparing my emulator output with the recording from the real chip), yet the other percussion operators are then operating on a much too …

Ah, I remember that rhythm DRO, and forgot to investigate this further... my current implementation also has the problem that the bass drum is barely audible, yet the other percussion sounds fine. The problem is that once I made this DRO's BD sound good, the other chiptunes I have lying around …

Remember to double the output for channels in rhythm mode: https://github.com/stohrendorf/ppplay/blob/ma … hannel.cpp#L175

https://github.com/gtaylormb/opl3_fpga/blob/m … th/opl3math.pdf

Hi, instead of trying to fiddle around with your code until it works, I'd suggest you simply copy my code and convert it to plain C ;) The thing is that my current code base is actually pretty bit-accurate (just read the comments here and here , or listen to Nautical , which is a direct dump from …