Hello all,
 
I recently switched my audio interface from a Presonus FP10 to a MOTU Ultralite mk3 hybrid.  I switched because I had built a brand new system (Core i7 920 - 12GB RAM - Windows 7 64 bit - SONAR 8.5.3) and at the time...Presonus didn't have a driver update for Windows 7 64 bit.
 
So far I am very impressed with the MOTU unit.  Great sound quality, features, etc.
However...I am noticing a very high pitched squeal that comes and goes quite frequently while in use.  I run from the MOTU's Main Outs to my KRK Rokit G6 monitors and have even tried switching to other outputs on the unit.  But it's still there.
 
I was just wondering if anyone else was perhaps experiencing the same thing.
 
Thanks for your time all. 

Mojo,
I have two 896's running under XPSP3.  The only time I have ever noticed a high pitched squeal happend when I accidentially shut off one of the two units while playing back audio in Sonar.
 
This sounds like it may be a driver problem specific to W7.  This is just a guess.  Sorry I'm not much more help than this.
 
Regards,
Rich

Hey Psalmist, thanks for the reply.  You know...your response makes me suddenly wonder if I should try switching from WDM to ASIO and see if that makes a difference.

I had it set to WDM because the book that came with the MOTU unit had a section in it for SONAR users and stated that SONAR is structured for use with WDM.

I used ASIO with my Presonus FP10. 

I will give that a try tonight and see if it makes a difference.  Thanks for your time.

Hey Psalmist,

Unfortunately that didn't work.  But Thanks for your time.  I'll keep investigating.

Thanks

I've got one and had some long conversations with MOTU over this.  Long and the short is, the official driver is buggy (read: unusable) with some USB controllers. The good news is that it works (for me) using Firewire with the official drivers on XP SP2 (32 bit) and Windows 7 (64 bit) using an onboard VIA controller, and they're updating the drivers to fix the problem with USB controllers.

I haven't had the problem you've run into though on either system.  Given my experience with their support, I'd post a report on the MOTU website being as clear and complete as you can and I reckon they'll work with you to try to identify the problem.

Mojo3432
I had it set to WDM because the book that came with the MOTU unit had a section in it for SONAR users and stated that SONAR is structured for use with WDM.

Hi.
 
I set my Ultralite Mk3 Hybrid before opening the book (as usual) with ASIO, for Sonar X2, and it is perfectly working so far. So I am not going to experiment with WDM unless I have some problem.
 
I am running it through the USB cable, and Windows 8 Pro 64 bit
 
Regards,
Manuel