View Full Version : Digital Audio Dropouts!

11-25-2001, 07:24 PM
A "should-this-work" question...

PT 180 (180MHz equivalent of a 7200 motherboard- confirmed elsewhere on gurus site)
VM is Off
OS 9.1
Quantum Viking 68-pin SCSI drive with 68-50 adapter
Software: Cubase 4.0 and 4.1
Cubase RAM allocated: 82MB
Disk Block Buffer Size (a Cubase setting): tried 64,128 and 256k.
RAM per track: currently set to 2048k.

I am trying to get a hold of a SCSI card that can support the 68-pin drive, but please, don't recommend buying any hardware, as this Mac is upgraded by donation only, where I'm from stuff is too expensive to spend much money on.

So the problem actually is, any more than a couple of simultaneous tracks and I get audio dropouts. It's particularly bad if there are any VST plugins on the tracks, as they tax the processor.

Disk I/O is minimal, but the CPU performance will eventually max out and the audio cuts out.

Any recommendations on how to alleviate? There are only a few more extensions I can try switching off!

PS, if I *did* buy hardware, would it make more sense to buy a good multi-input 24-bit 96kHz audio card, or spend the cash on a processor upgrade?

[This message has been edited by tachyon (edited 26 November 2001).]

11-25-2001, 11:02 PM
Usually drop-outs/stuttering is due to hard drive/PCI bus issues.


Due to your detailed description of the problem http://macgurus.com/infopop/emoticons/icon_smile.gif I think your on the right track when suspecting the processor.The fact that increasing the plug-ins makes it worse is a good indicator.


Is Cubase 4/4.1 known to be compatible w/OS9.1? This could be another angle. I don't have much experience w/Cubase so I dunno. I'm using ProToolsFree(cheap bastard http://macgurus.com/infopop/emoticons/icon_wink.gif) on my 8500/G3 400. It works fine w/my narrow 'Cuda. I tried to run PTF before I got my G3 and it took 10min. just to draw the windows! http://www.macgurus.com/ubb/eek.gif The ol' 120MHZ just couldn't hang.

I started out with nothing.
I still have most of it left!

11-26-2001, 04:05 PM
if there is a choice between an audio card and processor card go for the processor. it has the most bearing on your performance. get a G3 500 card. they're pretty cheap right now and as fast as a G4 500 for programs that are not altivec enabled which most audio programs are not.
with a 500 card and even with your narrow scsi bus you should be able to run 4-8 tracks at a time without problems.

11-26-2001, 04:07 PM
i can hear the creak of rocking chairs!

11-26-2001, 04:57 PM
Just a quick note...I use Cubase extensively, but I stuck w/OS 8.6 because of other software issues and I am currently at Cubase v.5.0 and waiting for my 5.1 update CD. My advice for info on OS compatiblity is to checkout the forums at www.cubase.net (http://www.cubase.net) and the www.steinberg.net (http://www.steinberg.net) knowledge base pages. I've seen post regarding older Cubase versions and OS 9.x. At the Steinberg KB there is a compatibility matrix that should tell you the short answer. Check out posts at cubase.net regarding cache settings. Some good info.
Good luck,

11-26-2001, 04:59 PM
I hope this is not an inappropriate post, but I do multimedia and am currently producing a Cubase Tutorial CD if anyone is interested. If it's ok, I'll post more info when it is ready to ship...

11-26-2001, 11:32 PM
Have at it, Kevin. Nothing inappropriate about it. We will be interested in your further info. k

12-17-2001, 07:29 PM
Furthermore, the OS Disk Cache is set to the default of 4096k. Will changing this setting have much effect on Cubase performance? The L2 Cache is only 512K, but I can get a hold of my old 1MB cache if the forum recommends.
I have since compared Logic Audio on the same setup and it handles more simulaneous tracks before coughing 'n' spluttering. What a difference software can make!
Also, if money is to be spent I can choose an Adaptec 39160 dual-channel for $150 or a Sonnet Tempo ATA-100 for just under double that. Space or speed?
PS ProTools Free does work, but it's a whole 'nother ball game.

12-17-2001, 08:06 PM
A Sonnet Tempo ATA-100 for just under double of what? $150? Meaning just under $300? I thought those cards were going for $100, about the same price as the ATA-66 cards...

12-17-2001, 08:31 PM
As I'm sure you know , Its Space+ Speed,and neither is cheap...a processor upgrade may be your best bet now....as the prices are right

12-18-2001, 10:27 PM
the_anarch: I'm outside of the US. The cards cost that much here. Anyway i'm broke, so I really shouldn't be drooling about this stuff anyway. Some old ATTO card might come along any day.

12-18-2001, 11:56 PM
tachyon: ouch. Sorry about the cost difference. Are the prices you listed US or AU?

[This message has been edited by the_anarch (edited 18 December 2001).]