Pronounced hiss on certain hi-rez albums with new DAC (MHDT Labs Orchid)

Support
#1

Core Machine
Mac Mini

Network Details
N/A

Audio Devices
MHDT Labs Orchid DAC

Library Size
20,000 Plus

Description of Issue

New DAC MHDT Labs Orchid (Previous DAC’s Bryston BDA-3 and DAC section of Oppo 105), using USB connection, the sound is excellent, with the exception of a pronounced “hiss” on a few albums. Not all most (about 30) that I tried were perfect, but 2 Hi Rez files, Brubek-Time Out and Shelby Lynne-Just a Little Lovin’, have a pronounced hiss.

Looking for suggestions on what I might have done in the set up to cause this? I’m sure it’s operator error. Thanks

#2

Have you tried using USB?

#3

Not sure why this should be an issue on hi rez only but I would look at those tubes first…

To eliminate the possibility it has anything to do with the resolution per se you can try a hi Rez piece where you hear the hiss and then play the same track from the “CD quality” version on your streaming service.

#4

Check the sample rates of the albums that produce hiss, then try other albums of the same sample rate

#5

yeah, did that and all good, no hiss. It’s really weird just those 2 files and they play fine on other DAC’s

#6

good idea, I tried that and other files of the same res work fine. The Brubek is 176/24 and the Shelby Lynne is 192/24

#7

sorry I should have said, it is hooked up via USB

#8

Try downsampling to 96kHz using Roon DSP Engine and see if the hiss is still there.

#9

Yes that could be it. The Orchid can process HiRez, but only our 44/24.

#10

The Orchid is fully capable of 192/24.
I owned one for about 6 months but connected by spdif.
Can you try spdif connection just in case something funky with the USB?

#11

So I bought the Mac mini so I could use the SPDIF if I wanted, but… this one, bought used does not support it, even though there looks to be a spot for the mini SPDIF that I bought for it. the system does not have the driver for it. So I hooked my computer back into the USB DAC section on the Oppo 105, and absolutely no noise on those 2 albums (via USB) dead quiet. It’s just so weird, doesn’t make any sense to me…

#12

Sounds like some very odd issue with the usb input of the Orchid.
But why just those two albums is beyond me.

#13

yeah, it’s so weird, and I love the sound of the DAC beyond that. I try about once a year to get into digital, then find myself just listening to vinyl, sell the current DAC the regret it about 6 months later and start the cycle again. But the DAC’s have gotten so good, and it’s so simple, I thought I’d try an MHDT again (loved the Havana back in the day), and I couldn’t find a used Bryston BDA-3 (what I sold back at the beginning of the pandemic since I wasn’t using it, but it was truly sublime in my system). I’ll get in touch with the guy in Tawain who builds these, he’s a great guy. Thanks for the help guys, I thought it was just my ignorance of Roon, and it was a setting I could change.

#14

Some playback chain can be sensitive to ultrasonic content. That’s why I suggest trying downsampling to 96kHz and see if that makes any difference.