Holo Audio May DAC

I'm hoping some of the MAY DAC owners here can help troubleshoot an issue I'm having with my recently acquired May (L2).

The unit has about 200 hours on it as I've been burning it in using my iMac via USB. About once every 15-20 minutes I get this digital "screeching" noise for about 1 to 2 seconds in duration. It sounds like when one of the Agents in the first Matrix movie inhabits and takes over another body. Zzzzhhhwweeee.

I've tried different output settings on the mac using Audio Midi Setup (44.1khz through 153.6 khz is available). I assume 44.1 is what I should be using since all imac files were ripped from CDs. Bit depth however is forced by the May at 32-bit. I would assume 16-bit should be an option and more in line with my file types, but it is not an option.

I have not noticed the noise when playing CD's and using the coax input on the May.

Any ideas?

I also run a Holo May DAC right out from the USB on my iMac, into an Auris Nirvana headphone amp. Before I did anything with the DAC, I just turned it on and left it that way for 3 weeks. These things require a LOT of burn-in, or so I'm told. But it sounds great and I've had no problems. And yes, I believe you are correct, @yakbob about the Audio Midi Setup... 

@yakbob

There are some having this issue using JCAT usb boards at high sampling rates, looks to be something with the chip used on those JACT boards. Appears to have been addressed via firmware from holo. Also I "think" there was mention about the midi setup used on macs - See this for ref

Thanks to you both for your replies.

@redlenses03 , your link to head-fi was helpful. It appears Macs and May dacs have had incompatibility issues. I wish i knew that before purchase.

Kitsune or should i say Magna hifi appear to be rolling out firmware updates for screeching sounds on Windows machines, but it doesn't really help the mac users since device drivers aren't required in the first place. If a firmware update to the May was availble, I'd certainly give it a try.

I have a support ticket into Kitsune, but wonder if I'm going have to unload this unit or try some usb to coax or optical converter,, which will defeat the purpose of having the "upgraded" Titanis USB on the level 2. 

If i can find a solution, Ill report back for any other mac users out there.

@yakbob 

I'm not sure what you mean by "however is forced by the May at 32-bit"

If you are using the upsampling in the May (that could be forcing it) otherwise nothing in the May is forcing the bit rate (to my knowledge), definitely turn that off and set May to NOS.  Then you can play native rates or upsample via an external program like HQP etc..  Of course all IMHO