# of Voices per DSP Problem

[SHIRK]

When I use more than 1 DSP for voices in the Playback Engine Setup, I hear little clicks and pops during playback (Sounds like a clock problem). If I just use 1 DSP, everyhting sounds fine. Once I use 2 DSP's (across two cards) at min/med/max voices I get these noises. Going further to 3 or 4 DSP's (across 3 cards) gives me the same problem.

I'm on a Powerbook G4 1.25Ghz / 1.5 Gig RAM / OS 10.3.5 / PT 6.4cs9 / HD3 (non Accel) in Magma 4-slot expansion chassis (w/ load resistor) / 192i/o / Sync i/o / external OWC Mercury Elite FW400 drives

Digitest says everything is OK

Playback engine settings are as follows:
512 samples / 85% CPU / 64 voices over 4 DSP's / ADC long Buffer / DAE buffer 2/

I've tried moving these settings around and heard no improvement. I've loaded up sessions that use up almost all of my DSP chips with plugins and everything sounds and behaves fine...so long as the the Voice Allocation is 1 DSP (core card) As I mentioned before, Once I use a DSP on the process cards for Voices, I get the noises. I tried switching order of the process cards and there was no improvement.

The loop master clock is the 192 internal. Tried using the Sync i/o's internal clock as loop master and saw no improvement. Because my setup works fine with only 1 DSP ( the one on the core card) that leads me to believe that somehow the proper clock signal isn't getting to the process cards ???

Could this be a problem with the flexcable that connects the Core and Process cards together.

Any ideas?

Steve

[SHIRK]

bump

[SHIRK]

Anyone? Digi?

[Seeee]

bad ribbon cable? just a guess.

[SHIRK]

Just tried a brand new set of flexcables between the core card and the 1st & 2nd process cards. Still no improvement. I had a bad DSP chip on my second process card so I had digi overnight a replacement process card. Today I got the replacement card, dropped it in slot 2 took out both of the original process cards, so that I was only dealing with a good working core card and a brand new process card and a brand new flexcable. What happens, same thing. 1 DSP for 48 voices....no problem, works great. 2 DSP's for 32, 48 or 64 voices....rice crispies...snap crackle and pop.

I just don't get it. This pretty much rules out that the problem could be in the flexcable. The core card works great when it's on it's own but when a process card's DSP is used for voice allocation, I get problems. Most times I can get away with working with 48 voices...but the minute I have to tell a client that my $20k rig can't do any more tracks becasue of %@#$$^%, I'm going to get look stupid.

Please digi, a little attention here. I'm stumped. Spoke to tech support yesterday, and they were like "uuuuugggghhh!"

[SessionKat]

Please digi, a little attention here. I'm stumped.

Hang on Shirk - I'm gonna get some answers for you ASAP.

-tv

[SessionKat]

Quickly Shirk, do you have I/O's on each card? And if so, is the "loop sync" properly connected? If not, this could certainly be the problem.
check it out if applicable.

-tv

[turbosynth]

Are you conforming to these track count/SR guidelines?

Performance - Track counts at DAE Buffer Setting 4

90 tracks @48K (2 slot chassis)
88 tracks @48K (4 slot chassis)
48 tracks @96K
16 tracks @192K

also be sure to use at least 3 FW drives on a session with more than 48 disk tracks at 48k (24 tracks per drive). Double the number of drives if you work at 96k. What's this about your FW drives being mounted in the chassis? Do you mean you are simply *racking* them in the chassis?

hope this helps,
~turbo

[SHIRK]

Yes, I have raw ATA drives that are simply mounted inside the chassis attached to a granite digital fw400 bridge. Then I mounted firewire sockets in the empty pci plate (4th slot). They attach to the laptop via one FW400 cable.

Yes I understand those guidelines you quoted. My problem has nothing to do with track count. It has to do with voice allocation across multiple DSP chips in the playback engine setup. If I only use 1 DSP for 48 voices(core card DSP)...all is cool. If I use 2 DSP's for 32, 48, or 64 voices(1 DSP on core card and 1 DSP on 1st process card) I get all kinds of crackling....even if I'm only using one of those voices. (Playing back a test tone, for example.)

Thanks for the thought though.

ss

[spinsong]

if theres's an option to connect the chassis to the desktop..then try that...that would rule out the chassis if the cards pass...and what you would be looking at is a bad or uncompatible pcmia port on the laptop or a bad pcmia card

good luck