828mk3 Digital "screech"

[nooneknows]

Hey all,

Swapped out my 828mk2 yesterday for the 828mk3. Opened up some projects in Logic that have all been solid with the mk2... and now randomly... I'll get digital noise (screeching) from the mk3. It happens during playback... I have ADAT A IN & OUT hooked up to a PC running GigaStudio... and SPDIF IN & OUT going to my iMac... all the clocks are set correctly... didn't have any problems with the mk2.

The odd thing is that I can't reproduce it manually... it's totally random... the mk3 will go hours without a screech, and then bam... To fix it I can simply change the clock to something else, then back to internal. Or simply RE-disable Optical Input Bank B... or Output... doesn't matter... basically simply forcing the mk3 to change a setting fixes the isssue (changing a setting related to the Dig Ins and Outs, cause changing say the default stereo in doesn't do anything).

I did some more troubleshooting and here's what I found...

I remember having "screeching" issues years ago when I first bought the 828mk2 and used it with my PC. Basically whenever I played back audio or accessed the hard drive, the mk2 would screech and cut out. I believe it was eventually fixed with an updated PC, and I eventually started using it on my Mac instead... can't remember the exact solution. Although I do remember that it seemed to be a FW bus issue, from accessing a FW disk.

So I turned on my backup FW800 drive connected to my Mac to run some tests. Theoretically the FW800 & FW400 bus should be separate, but I vaguely remember reading something about some FW bottlenecks on the initial G5's (which mine is).

-I played back a Logic sequence, and then proceeded to copy a 1GB file from the FW800 drive to my desktop... sure enough the "screeching" started.
-I closed Logic, turned off the mk3, plugged it into the other FW port on the front, turned it back on, booted up Logic... pressed play, copied the file... NO screeching.
-Figuring that it's very unlikely the front FW port makes any difference, I repeated the same steps again and plugged the mk3 back into the front... screeching happened this time.
-Closed Logic, mk3 off, plugged it into the back again, mk3 on, Logic up, pressed play, copied the file, NO screeching.
-I repeated this numerous times and sometimes there'd be screeching sometimes not... the only thing I can deduce from this is that power cycling the mk3 is fixing / causing the problem.

That was hours ago, and I haven't had any screeches since. Obviously this is not a fix, and hopefully it's just a driver issue, in which MOTU can fix easily. I have 1) updated to the latest drivers BTW from MOTU's site, 2) Factory reset the mk3, 3) Tried a different FW cable... although the cable shouldn't matter as the mk2 I just disconnected was fine with the SAME EXACT IN & OUT connections.

Just disconcerting, I love the mk3 otherwise... but I'm wondering if I have a bad unit and really don't have the time to go through all that troubleshooting with MOTU to figure it out... i.e. OS reinstall, etc.

Anyone with an mk3... using the ADATs... having any similar problems?

[1nput0utput]

Theoretically the FW800 & FW400 bus should be separate, but I vaguely remember reading something about some FW bottlenecks on the initial G5's (which mine is).

Actually, no. All Apple computers with multiple firewire ports (either FW400 or FW800) have a single firewire bus that is shared by all ports. To gain an additional firewire bus, you must install an expansion card.

[slicerecords]

i'm having similar problems, but with the SPDIF I/O. Every once and a while a Triangle wave like screech emits form the SPDIF outs, I usually just turn the unit on and off and it's fine for a long time, it's only happened twice,

I also can just reset the clock, that fixes it.

--stumped, but not a huge deal---would like it to completely work properly though.

Seems like something that can be fixed via driver support or firmware update. A hardware issue would be more consistent.

anyone else have ideas or the same problem

[nooneknows]

slicerecords,

I have done some more testing and here's what I've found:

-Does not matter what FW port I use...
-Could very well be dependent upon my system...

BUT - Sometimes I don't have the problem AT ALL... i.e. I close Logic, turn off the mk3... boot it up... open Logic... start playback, start a test copy from my FW800 drive to the desktop... and NO Screeching at all... no matter how many files I copy, or how many times as reboot, close Logic, etc... as long as I don't power cycle the mk3 again... it will work for hours and hours without ANY screeching.

Power cycling the mk3, and then running the same tests still will USUALLY cause the screeching... but then again I AM able to get the mk3 running without the problem...

So I'm at a loss... it's totally random... sometimes when I turn it on it works (and I feel like it would work for a year straight), sometimes it doesn't. I'm going to call MOTU tech support and see what they think... probably a driver issue... but I may possibly swap it out for another mk3 just because I want to be certain it's not the unit itself, as sending it back to MOTU for a warranty claim will be more of a hassle.

[wmorris]

I have actually seen this same problem with an 828mkII when using the optical outs with Logic. I always managed to fix it by turning the optical output on and off again. Its is an odd problem, as when I this same unit is with DP5 or Cubase SX3 it has failed to ever have the same problem.

I'm not sure if you are using the newest version of Logic but this my fix it. As I had this problem with version 7.

[nooneknows]

Please other PPC G5 828mk3 w/Logic users post your experience so far...

I have found that I don't have the problem when the 828mk3 is on my Alum Intel iMac...

But the Dual 1.8GHz G5 I'm using has basically a brand new Logic board, and the mk2 does NOT have these issues with the same setup...

[nooneknows]

For anyone following this thread...

I just swapped out my 828mk3 for a brand new one... got it home, hooked everything up... ran through all the same tests... and so far NO digital screeching at all. I'll post back later today or in a few days with a follow up... which will hopefully still be "no screeching."

Anyhow, for anyone who gets a new 828 (or has an existing one) and has this issue... RETURN IT! or send it back to MOTU and if it's out of warranty pay the $79.99 for them to fix it.

[loude]

Still no screeching nooneknows?

I've got nothing connected to optical or SPDIF and I get the intermittent screech on my PPC G5. It's showing as a consistent signal on the SPDIF outs in Cuemix's meters.

If your new unit is screech free I guess it's a hardware issue and not necessarily ever going be fixed with an update. I'm still hoping I don't have to return mine as I bought it in the US but live in Tokyo.

[nooneknows]

Actually, the unit that I had with "no screeching" basically froze up on me the 2nd day I had it and was essentially fried for some reason. I returned it again and the 3rd unit screeches as well...

[ChiantiM]

http://www.thesycon.de/eng/free_download.shtml

The above link will take you to a piece of software that when downloaded will show the load placed on your system by the Wireless NIC. Try updating the driver; or disabling Wireless connectivity during PlayBack/Recording.

[nooneknows]

ChiantiM,

Thanks for the tip but unfortunately in my system does not even have a Wireless card installed...

[lundbergj]

I also had the same problem, but after doing this:

1) Factory reset
2) Disabling all digital I/O
3 Disconnected my powercore firewire

it stopped. Obviously not a solution either, but it might point you in the right direction. I will actually try to get it back again as I'd lite to know exactly when it happens so that I can update my support request at motu.

There is something really wrong about the mk3, my mk2 just worked all the time but this new thing has been a nightmare since day 1.
Probably software and they have promised firmware updates already.

[nooneknows]

lundbergj,

Thanks for the input... I've tried all of these steps numerous times. I too came from an 828 mk2 and it was rock solid. MOTU has given me some beta drivers which have helped for the most part. That is, I do get the screeching sometimes, but overall there's none... also not a perfect solution.

I've purchased an Apogee Ensemble in the meantime and it's great... I'll probably be returning the mk3...

[Todd Woolsey]

I have the MkII and I get random screeches as well. I usually have to go into hardware setup in DP5 and turn off the 828 and turn it back on and reselect it(although I haven't tried changing the clock setting like stated earlier). This fixes the problem.....until the next screech. Actually, it's not ussually a screech, it's normally just fuzzy digital distortion over the audio.
It can effect itunes as well so I guess it's something between the 828mkII and my OS 10.5 Operating system.
I'm running OSX.5 Dual G5 2.O GHz.
If anyone knows a fix for the mkII and this problem, let me know.
Thanks,
Todd.

[sambeste]

I'm having exactly the same problem with a Motu 828 mkII and a Motu Ultralite, both of which are brand new. It happens very frequently in my system, several times every day. It's incredibly frustrating and often ear splitting.

Although I have experienced the problem a lot in Logic, it also happens when I'm playing back audio from iTunes or Quicktime so it seems to be a problem between OSX and Motu.

Not only do I get screeching noises but the motu display starts flipping out too. All the LED's start flashing erratically and I sometimes get some sort of error message in the main display which simply says "niaG"?! Has anybody else experienced these problems too.

Hopefully one of us will find solution soon.
Thanks,
Sam