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Originally Posted by Bruce Abbott
Define 'accurately'.
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Something like "
you would not be able to tell that it wasn't a YM".
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Originally Posted by Bruce Abbott
Paula has 14 bits per channel, which should be plenty enough. But as you say, this is the smallest problem.
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But then you have to change both the sample and the volume, which makes matters a little more complex than just altering volumes. Especially when fast volume changes need to be applied.
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Originally Posted by Bruce Abbott
Not that strange, it just sums the 3 DAC current outputs in a single 1k resistor. This causes compression at higher levels, with the level of each channel affecting the others. On my AY/YM board each output is loaded individually with 470 Ohms, which virtually eliminates compression and interaction.
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Strange or not, the end result is that you can not simply compute the output level for any given configuration. Or i want to see the formula !
Quote:
Originally Posted by Bruce Abbott
On the ST this is true, since low pass filtering is applied with a cutoff frequency of ~2kHz.
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Oh, and i forgot this one as well. But the output from the mixer, before filtering, is already not perfect square waves mixed together - that was the point.
Quote:
Originally Posted by Bruce Abbott
And those same musics could well 'fail miserably' on my own actual YM2149 (assuming I could even get a player for them).
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If it's in another machine type, that may indeed be true. I was very deceived when i attempted to get my old oric tunes to the ST. Same kind of chip (AY-3-8912), just 1Mhz diff so all periods should be multiplied by two -- but an end result not sounding at all like it should (note frequencies ok, but nearly all volumes gone wrong). Not that the mixing was linear there either...
Quote:
Originally Posted by Bruce Abbott
This is where you went wrong. I never said anything about emulating an ST, but simply reproducing the 'sound' of a YM2149 - the same way we can reproduce the 'sound' of a piano or a guitar. Yes, there will be differences between that sound and various YM2149 implementations (which themselves have their own slightly different sounds) but unless you define 'better' to mean 'closer to the exact sound of an ST', the Amiga is objectively better because it can play AY/YM style music and more.
Making the ST's sound the 'gold standard' (that makes other platforms no better because they can't easily emulate it exactly) is silly because in the ST the YM2149 is crippled by its mixer circuit. It's not even as good as a YM could be, let alone as good as an Amiga.
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Well then, we weren't talking about the same thing.
I haven't said the YM is in any way better than an Amiga, so far not. It has its distinctive sound, some like it, some don't, no more no less.
Nevertheless, emulating it is my problem, and if possible with small enough cpu footprint. Hopefully currently all my ST game ports are satisfied with simple emulation...