Problems with PCI-424e + MacPro+DP

[Wave]

Has anyone had any problems with getting their PCI-424e card to work in their MacPro? I am on my 3rd card from Motu and I am unable to use my new HD192 reliably (without distortion, clicks, pops) at any rate higher than 96kHz. I sent the HD192 to MOTU to verify that it works OK, and according to their tech support the initial culprit was a faulty 424 card. Again, at this point I am unable to get the 3rd card they sent me to work reliably.

I already went through all possible permutation of cables, slot locations in the MacPro etc, etc.

Is there something I am missing, or are there problems with 424 cards?

The rig works perfectly when Input Monitoring Mode is set to "Direct hardware playthrough" and I am able to use it at 192 KHz at any buffer size including 64. When the Input Monitoring Mode is set to "Monitor record-enable tracks through effects" I am getting distortion.

There are no other cards in the MacPro except the video card, and the only interface attached to the computer is the possessed HD192.

The only plug-ins installed on this mac (and not inserted into any channel) are Altiverb 6 and RND Inspector XL - not that it is probably relevant.

Any suggestions would be greatly appreciated, as I am ready to send the HD192 system back to Motu and get an Apogee Rosetta 800/192.

On a positive note, the Motu tech support has been very responsive and helpful, but I am running out of time and patience.

Thanks, Wave

[Frodo]

Has anyone had any problems with getting their PCI-424e card to work in their MacPro? I am on my 3rd card from Motu and I am unable to use my new HD192 reliably (without distortion, clicks, pops) at any rate higher than 96kHz. I sent the HD192 to MOTU to verify that it works OK, and according to their tech support the initial culprit was a faulty 424 card. Again, at this point I am unable to get the 3rd card they sent me to work reliably. ...

Sounds as if you've done all the right things. Your THIRD card? Man, if MOTU can't nail it down for you and you're done with the chase/wait game, then I'd say go the Apogee route without hesitation. MOTU tech support has always been helpful to me, but it's always a tough call if they say that your equipment checks out on their system.

It bums me out to hear that anyone is going through this. That HD192 is a great unit.

The only other thing I could suggest just as a troubleshooting measure is to review your gain staging to make sure that monitoring record-enable tracks through effects is not overloading your signal. Makeup gain on effects can sometimes cause the problem-- maybe pull those back some just to see what happens?

Try removing the effects altogether just to get a clean signal.

Dunno-- grabbing at straws here. I have had problems with both my 324 and 424 cards over the years, but not right out of the box.

[Wave]

Dunno-- grabbing at straws here. I have had problems with both my 324 and 424 cards over the years, but not right out of the box.

I know, I have been using MOTU gear for years and never ever did I have any problems before. I am what you may consider "Motu-Religious" and this is a real bummer. The box sounds really nice at the lower sampling rates and I'd love to keep it, but I can't afford waiting for months to have this resolved. The gain staging is of no relevance since all I am doing to test it is to send direct signal from my CD player right into the input of the HD192. The meters as you can imagine read comfortably at 12, 15 on both input and output. What is really weird is that when I select sampling rates higher than 96, there is an audiable distortion not only in the channels used for output (obviously, just like in case of other MOTU converters you can use any pair of channels), but also in the neighboring channels i.e. if I use inputs 1,2 I would see distortion on 3,4, if inputs 3 and 4 are used there is distortion in 5 and 6. This was confirmed by the MOTU tech who examined the entire Core system when I sent it to them for testing. There are absolutely no effects in the inserts that would cause problems, so I am truly running out of ideas. Of course, I tried both 424 and HD192 as a master clock device, but to no avail. What is really weird is that the Direct Hardware Playthrough doesn't cause any problems. Anybody has any suggestions to help me keep HD192? We'll see what my MOTU tech has to offer tomorrow.

Thanks for your support Frodo

Wave

[Frodo]

Wave-- glad to offer support, but sorry that I don't have a solution.

Please keep us posted of your progress-- and I hope MOTU has some useful suggestions for you.

It starts to make sense that the higher sample rates are what's causing the problem-- correct me if I'm wrong. 96k is a considerable increase over 48k....

Hey-- have you tried adjusting Max Work Percent, Prime Seconds, and Work Quanta?

Prime Seconds is a look-ahead feature that determines how far in advance DP sets up samples to stream before playback begins. Raising this a half second at a time might help, but it may also add latency (so adjust carefully).

Max Work Percent governs how much CPU power is allocated to graphics and how much is allocated to audio. Raising this number might give you some reduced graphics display functionality (ie: zoom and wiper scrolling, window redraws, etc.), but a higher number (raised 1-2% at a time) can add more "mmph" to audio performance.

Work Quanta governs the frequency of when DP's audio engine crunches its numbers. According to MOTU, this appears to have more to do with MAS, but how this impacts AU under DP's audio engine is something I do not know with any certainty. I do suspect they are interdependent, but how much? Not sure. As with the other two features, raising the number is done at the risk of losing of some graphical display smoothness, but perhaps some experimentation with fine tuning can tip the scales in your favor.

Firewire and USB2 drives can also struggle with porting data. Given that the higher sample rates force the hard drives and CPU to work harder to get larger amounts of data from point A to point B in the same time as it would while porting data at lower sample rates in the same amount of time.

Still scratching for workarounds...

Best of luck!

[Wave]

Dunno-- grabbing at straws here. I have had problems with both my 324 and 424 cards over the years, but not right out of the box.

Not giving up yet. Motu tech support (namely Berrett) is on the ball trying to get this mystery resolved. I'd love to hear "you dumb ass, it is the end user error", but unfortunately, that would be too easy

Will let you know when I have something of substance to share

Wave