Integer is King? - the challenge

[living sounds]

BTW, those video game emulators are an interesting (yet flawed, I'm sure) example: I don't know about today (haven't tested it for a long time) but all those emulators on PCs incredibly more powerful than the original machine could never reproduce the smooth scrolling (a hardware function) of the humble C64.

[Shy]

What Yamaha FM chip was emulated bit identically? That would have to be a very simple one.

[JonasNorberg]

everyone here surely knows EQs do affect phase.

Google for "linear phase eq" and you will find several product offering eq with no phase smearing.

Everything comes at a price though, and linear phase comes with the price of a small extra delay (sometimes negligible)

[thorkz]

Z is the integer code.




oh shit, its all true.

[living sounds]

Well, I was talking about analog EQs. And linear phase... I'm always wary about those - pre-ringing is a sure way to destroy bottom tightness in every signal. BTW, could you avoid this alltogether (in the audible range, it probably won't matter at 5 Hz) with very long delays?

everyone here surely knows EQs do affect phase.

Google for "linear phase eq" and you will find several product offering eq with no phase smearing.

Everything comes at a price though, and linear phase comes with the price of a small extra delay (sometimes negligible)

[vonRed]

BTW, those video game emulators are an interesting (yet flawed, I'm sure) example: I don't know about today (haven't tested it for a long time) but all those emulators on PCs incredibly more powerful than the original machine could never reproduce the smooth scrolling (a hardware function) of the humble C64.

That's only true if those PC's don't use multiples of the C64's video refresh rates, and hardly a mystery.

What Yamaha FM chip was emulated bit identically? That would have to be a very simple one.

Several are, with only detils like the noise generation exhibiting differences in others. They aren't that simple BTW, they have LFOs and envelope generators etc. They are, however, documented and with some tinkering you can hook them up to a PC to poke at them.

[whyterabbyt]

That's only true if those PC's don't use multiples of the C64's video refresh rates, and hardly a mystery.

the fact that they wont be outputting through a 30c composite video output and into a shitty TV intended for viewing from 15 feet away is probably just as significant. i doubt if he's ever done a like-for-like comparison.

[mauseoleum]

Now I bought Adams last week

which ones? A7?

[Shy]

What Yamaha FM chip was emulated bit identically? That would have to be a very simple one.

Several are, with only detils like the noise generation exhibiting differences in others. They aren't that simple BTW, they have LFOs and envelope generators etc. They are, however, documented and with some tinkering you can hook them up to a PC to poke at them.

Not a single FM chip has been emulated bit identically, even the extremely simple ones. As for the less simple ones, those with very characteristic aliasing (which is not by chance and not random, but -designed- aliasing by Yamaha), nothing comes anywhere close, and it's no wonder why some Yamaha chips and various FM synths sound very characteristic and have favored sound. They have smart antialiasing in various parts of the FM, and that's what really makes most of their sound.

edit: meant antialiasing, obviously. Go ahead trolling that I meant the aliasing itself is smart, as if you didn't understand my point. If you you never mixed up a word and its opposite until someone pointed it out to you, great for you, you're a wonderful, non-dyslexic, native English speaker.

[AdmiralQuality]

[whyterabbyt]

They have smart aliasing in various parts of the FM, and that's what really makes most of their sound.

reference please.

[Shy]

They have smart aliasing in various parts of the FM, and that's what really makes most of their sound.

reference please.

Refer to and use Yamaha FM synths if you want to know what does what. There are many patches, including preset ones, taking advantage of specific aliasing in their synths.

[vonRed]

Not a single FM chip has been emulated bit identically, even the extremely simple ones.

Really? Where did you get that bit of misinformation?

As for the less simple ones, those with very characteristic aliasing (which is not by chance and not random, but -designed- aliasing by Yamaha), nothing comes anywhere close, and it's no wonder why some Yamaha chips and various FM synths sound very characteristic and have favored sound. They have smart aliasing in various parts of the FM, and that's what really makes most of their sound.

You can analyse the output of the things, and verify that your emulation of it does indeed output bit identical signals. This has been done, it's how the emulations were developed.

[Shy]

I've never heard of a bit identical emulation of any FM chip. If you have any reference to anywhere that demonstrates it, please show it.

[MadBrain]

What Yamaha FM chip was emulated bit identically? That would have to be a very simple one.

Several are, with only detils like the noise generation exhibiting differences in others. They aren't that simple BTW, they have LFOs and envelope generators etc. They are, however, documented and with some tinkering you can hook them up to a PC to poke at them.

Not a single FM chip has been emulated bit identically, even the extremely simple ones. As for the less simple ones, those with very characteristic aliasing (which is not by chance and not random, but -designed- aliasing by Yamaha), nothing comes anywhere close, and it's no wonder why some Yamaha chips and various FM synths sound very characteristic and have favored sound. They have smart aliasing in various parts of the FM, and that's what really makes most of their sound.

Well, I can say that the OPL3's emulation is not *perfect*. Afaik, MAME's code doesn't emulate the pseudo-exponential curve of the enveloppes (it uses real exponential curves instead!), has too low volume precision on the square wave, and messes up one of the 4-op algorithms... but there's almost no song that uses those anyways (except the one I wrote).

As for aliasing, emulators might use different sampling frequencies, which means that sounds making intential use of aliasing (hihats and other cymbals) won't sound right, but aside from that, there's really nothing special about aliasing in yamaha FM synths. They simply didn't have the number crunching power to do anything about alias, and if they had it, they would have spent it on other stuff (filters, more oscillators/channels, sample playback...).