Pops in audio bouncing to disk with Koblo / Direct Connect

[tld]

I've already submitted the following as a bug report to Koblo but was wondering if anyone else experienced the following:

I have been experiencing a problem with pops in audio on a session when bouncing to disk. I was able to narrow it down to a fairly specific set of circumstances bescribed below.

Here's my system:

Protools 24 MixPlus 5.0
Most Current Direct Connect
Koblo Studio9000 version 2.5
Mac 9600/350 256 MG Ram
Mac OS 9.0 (not 9.0.4)
One Apogee AD8000 interface

This is the setup causing the problem:

Protools midi track driving Stella9000 Sampler.
Stereo aux in protools receving audio from outs 1-2 via DC.
DSP about maxed out, no available chips on the card that DC is running on.
Bouncing session to disk, 24 bit split stereo.

Under the above circumstances (only when bouncing to disk) I am getting intermitant unpredicatble pops in the audio. They can be heard while bouncing to disk, and wind up on the bounced files. Several presets did this, but it was most noticable using the 'Multi Organ' preset. I was able to create a simple session and duplicate this to rule out a corrupt session etc. I've also ruled out a currupt Tokyo project file by creating a new one from scratch. If I route the audio to audio tracks and record them rather than bounce to disk, all is OK.

I've tried all the obvious stuff, trashing prefs, running DigiTest, ruling out clocking problems. Everything about my system seems fine aside from this.

Thanks in advance for any advise.

Tom

[This message has been edited by tld (edited May 29, 2000).]

[This message has been edited by tld (edited May 29, 2000).]

[This message has been edited by tld (edited May 29, 2000).]

[tld]

If anyone out there is running DirectConnect with Koblo, preferrably on a 9600 with OS 9, I'd be very greatful if they could see if they can reproduce this problem. It's a fairly easy test to set up. As I mentioned, it's most noticable with the 'Multi Organ' factory preset. It's possible it's realted to the LFOs in the preset(??).

I finally heard from Koblo today and was not happy with their reply. They suggested causes such as: Disk fragmentation (even thouhg I get this bouncing to an empty barracuda with NO audio tracks in the session, just a Koblo buss), CPU being used by things such as the Protools GUI (which does NOTHING during bounce to disk)...etc

They apparently did not try to reproduce this on a 9600. If anyone out there could I'd appreciate it. This one is causing me major headaches. It forces me to record the Koblo to disk prior to bouncing the session, which usually forces me to free up DSP to assign busses etc.

Thanks in advance.
Tom


[This message has been edited by tld (edited June 08, 2000).]

[tld]

One more note on this. My test session had a reverb plug on the Koblo aux buss, and the pops I'm getting have obvious reverb on them. This indicates that is is coming from that buss, either from Koblo or Direct Connect.

[Digi Engineering]

You might try setting the DAE buffer to "0".(from the DAE app, select the buffer size dialog and then relaunch ProTools) This will use smaller intervals for the main DAE disk activity, and might help prevent Koblo from losing CPU time.
-Toby Dunn

[tld]

Thanks Toby, I'll definately give that a try. It's a little hard to believe that my problem is related to high disk activity however. I have no problem playing a dozen audio tracks running at the same time as three Koblo synths, yet bouncing a test session with nothing except one synth (and no audio tracks) causes the pops. Yet recording the same test session to a pair of tracks (rather than bouncing to disk) works fine. It seems to me that that would have the same disk activity and most likely more cpu usage.

The Stella presets where these pops seem to occur have similar use of LFOs. I'm going to see if I can determine if it's specific to those. I will definately give the DAE buffer size change a try. Thanks again.

Tom

[tld]

Tried the buffer size change...no luck. The test session I'm duplicating this in does not push any part of my system...memory, cpu, disk. The only thing near maxed out is TDM. Man...I gotta think this is a bug in Koblo, or something between Kolbo and DirectConnect.

Once again, if anyone has a similar setup and could try duplicating this, I'd appreciate it.

Tom

[Altrack]

I use to get pops and nothing I did fixed it. Call it pure coincidence but it seemed to only happen when I was bouncing. Well, it turned out that when the refrigerator in the kitchen turned on, I would get a pop. When I told this story, I couldn't believe how many people called to thank me. My electrician fixed the problem by putting my outlets on a seperate breaker.

[tld]

Wow...interesting. I'm afraid my situation would be a bit too much of a coincidence. In six months of work I never got a pop doing anything...bouncing...whatever, and still don't, except with the above setup. And I can duplicate those in a test all day long. I'm starting to think it's a bug I just have to work around by recording synths to disk before bouncing. It's a pain, but it works.

Tom

[JamesState]

I have experienced the same problem with Unity and directconnect. I guess it's nice to hear that someone else experiencing the same problem... My pops only occured at the very beginning of the bounced region, and I attributed them to my starting the bounce right when the audio begins instead of leaving a bar of silent lead-in. I haven't done this more than a couple of times, so I'll keep an eye out for it. Sorry I don't have any solutions. But maybe it's a directconnect problem, not a koblo problem.

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James
[email protected]

[tld]

Very interesting. This is the first sign I've had that it's not just me . The test I did was a simple session with just one synth, and a dummy buss just for instantiating plugins to max out the DSP. If you are having the same problem as I am, all you have to do is set up a session like this, and keep trying the bounce to disk. If you don't hear the pops fairly soon after starting, cancel the bounce and try again. I've found that, if it doesn't create the pops immediately, it never takes more than about two or three tries to duplicate the problem.

If you get it, then maybe it is an illusive problem in DirectConnect. Since I hear reverb on the pops (with the reverb instantiated on the DC input buss), it has to be either the synth or DC.

Thanks for the reply!

Tom