polyphony rise with DSP expansions?

[Tim Kleinert]

I'm wondering what kind of polyphony gain to expect with the expansions. Because, as you probably know, patch polyphony is determined by several factors:

1) computational DSP load
2) module memory load
3) module output zero page usage

Point No.3 is what makes me suspicious. I quote Rob:

[mosc]

I haven't received my G2 expansion board yet, but based on my experience with G1 and on what I've heard, you can expect to double the polyphony.

The DSP boards also contain the memory used for samples (delays, reverb, etc). This doubles. I'm not sure what zero page memory is, unless it is memory associated with the non-dsp general purpose auxilliary processor. This is used for I/O scaning, patch managment, global synth settings etc. This won't change but it isn't related to polyphony.

[blue hell]

[Tim Kleinert]

Excellent news!

[Anig Browl]

Zero page means that there is no paging cycle to read those memory values. Motorola DSPs are multi-threaded so when you are reading in memory from an external buffer (eg the G2 delay line) you can program the chip to do something else until the internal memory is full and has to be processed. So you can have ~104x4 modules in an unexpanded G2 using interslot communication.

Jan, I saw you commenting elsewhere on the possibility of very very large noodles using itnerslot communication. But it appears to me as if the expansion will simply provide two parallel G2s, rather than allowing the 8 DSPs to be manipulated seperately. Thus you could have two identical big 4-slot noodles going on at once, but not a single one utilizing all 8 DSPs (routing the signal in a loop on the rear inputs wouldn't work as the input routing would also be duplicated in the patch.

I kind of wish Clavia would let the extra DSPs be used freely, although interslot communication might become too complex - can't recall if the DSP has sufficient plumbing to handle 8 incoming channels. I really do not care all that much about polyphony, although I have succumbed to the temptation to play chords more often When I had a micro modular I hardly ever minded having limited polyphony (even though I didn't have much other gear), though I longed for more timbrality so I could play more than one patch at once. The expansion board seems very competitively priced, but if it is simply a polyphony expander then I think I'd rather get an Evolver.

Then again I wish they'd put on a sensible amount of RAM too instead of a mere 256 kwords, it's not like it would have added more than about $20 to the cost. Ah well you can't have everything.

[blue hell]

Hi Eddy, good to see you pop up !

[Rob]