nothing what developed human is underrated, it is upon to you and your creativity what you do with that

It's obviously not a filter sweep, but the effect it has on the harmonic content is similar in that decreasing the modulation index eventually leaves you with only the base tone, and increasing it gradually introduces more higher frequency partials, not unlike closing and opening a low-pass filter respectively. I'm not sure what you mean by only having one overtone at your disposal.

Thats why he used the words "SWEEPY". Perhaps "SWEEPISH" would have been better,

That's nice and all, but it's not a filter sweep. You only have one overtone at your disposal at a time, which you can change the amount of influence of.

You can get pretty filter-sweepy sounds out of any 2-op synth with feedback modulation, or at least a patch that goes from no harmonics to a lot over the TL range. Here's a sample of my own 2-op FM 303 emulator thing: http://soundcloud.com/boomlinde/r-odent-dx303. I guess that with some imagination, those sweeps could as well have been filters.

Not sure you can get the fizz with only sine waves. The modwheel trick should work though

Can't you do that with any DX/TX synth?

Basically make a nice filtery patch with op4 doing lots of feedback then assign the modulation wheel (with a square wave lfo) to control the amplitude modulation sensitivity to op4. you can then use the mod wheel to turn op4 up and down which "opens" or "closes" the filter.

Depends what is wrong with it, if it is the battery or reseating a couple of keys should be pretty easy, I have done both and I am a hopeless 10thumbed goon at electronics,

That's cool, I didn't think any of the old Yamaha synths had a pitch envelope. FM8 has it which is a huge boon for programming drums and sound effects. How does the "fake filter" work? Usually I don't bother with filters for FM, but FM8 has a separate filter operator which I can actually use to modulate before the output signal, which is really cool and gives me even more options for altering the timbre.

Do you know how easy it is to fix? There's one on eBay (advertised as spares/repairs), that's in driving distance, if I could get it for a silly low price, dunno if it'd be worth a punt :\

Oh, one more good point. The bass is absolutely terrifying.

yeah it looks gooood! seems like it's harder to get a hold of one than a dx-7 though, at least in australia

i hate my tx81z

Sorry, I was updating the post, submitted when I should have previewed!

The same for me. And here is why: it is the only invisible synth ever made.