Schiit Yggdrasil Impressions thread
Feb 16, 2020 at 1:35 PM Post #9,871 of 12,119
I installed the Unison USB card in my Yggdarsil A2 and yes, it made a difference.

The actual install was easy, 32 screws and 25 minutes. The directions here are spot-on: https://www.superbestaudiofriends.o...ggdrasil-gen-5-usb-upgrade-instructions.4842/

The change that I have heard is an improvement in note separation and a sharper attack. I noticed the most change in the treble with improved clarity. The difference is not dramatic, but more akin to the difference I have experienced when upgrading USB cables.

I use a Surface Pro laptop feeding the Yggy though a Curious Cable.

Definitely worth the $150 to me.

As always, YMMV.
 
Feb 20, 2020 at 6:00 PM Post #9,873 of 12,119
Yes, this is it exactly. The first thing I noticed was the hardness/harshness was gone. I didn't even realize it was there until it wasn't. With it gone, the bass was cleaner and the treble was less glaring. I can turn the volume up a few db now and not get discomfort that I sometimes would previously. Some of the details in the music are more apparent now also. Easier to pick out.

With my other setup, I use a Singxer SU1 and convert the USB into I2S and coax SP/DIF. Nice, clean signal. I would say the NUC straight into Yggdrasil via Unison is at about the same level now.
I received a PS Audio PW-12 (pure silver)I2S cable today. Never thought the cable can make such a huge improvement in sound. No wonder those guys spent $1000s on cables.
 
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Feb 24, 2020 at 6:48 PM Post #9,876 of 12,119
I would be interested to know if anyone with a Yggdrasil GS has installed the Unison USB upgrade?

I have an early Yggy and have The unison board installed. Had the Gen 5 before, and I hear an improvement. Biggest change is better shimmy on cymbals and a tighter and cleaner bass. The difference Is not night and day, but certainly worth the 150. I’m happy.
 
Feb 26, 2020 at 3:24 PM Post #9,877 of 12,119
Hello,
I'm considering the USB Unison upgrade, which is said to extend 2 more years of warranty. However, I am not the original of the item. I wonder if Schiit honours the warranty for non-original owner in this case?
Thank you.
 
Feb 26, 2020 at 6:16 PM Post #9,879 of 12,119
I'm considering the Unison USB upgrade for my Yggdrasil. One possible theoretical drawback has occurred to me.

I am presently using a Samsung S4 tablet with the UAPP software Android USB driver as the USB source output to the Yggdrasil USB cable input. Sonic performance is really good.

The USB power from the tablet is already presumably very clean and noise-free because the tablet is battery-powered.

The Unison USB upgrade to the Yggdrasil apparently uses Yggdrasil-generated power for its USB processing rather than the USB power from the cable source, so wouldn't this possibly degrade performance in this particular case because tablet battery-generated power is cleaner than power converted from the noisy power lines?

Of course like everything in high end audio it's really a tradeoff. The Unison modification has a lot of other improvements not related to noisy USB power, that would presumably more than compensate for this drawback.

Just a little concern that occurred to me. Any comment?
 
Feb 26, 2020 at 11:56 PM Post #9,880 of 12,119
Just a couple of thoughts to consider.
#1 the tablet is still a digital device and it is it's own ground, which also means the operational noise of the computer operating IS on its ground in one form or another. It's true it doesn't have ac to dc power supply noise, but in my tests the digital operational noise just swamps the power supply generated noise.

#2 These USB boards starting with the 5 gen boards use isolation input/output transformers to electrically isolate the incoming and outgoing USB signals from the dac.
So it doesn't matter which device is the source of the USB power because they both are.
Because they are not connected to each other, electrically.
And so from a certain perspective each 'side' of the USB cable uses it's own power. The Schitt dac powers itself and the tablet powers itself and they share data but not ground nor volts.
This is the way that ethernet network cables operate as well, which is what they did, they used ethernet network isolation transformers and isolated the internals of the USB card from the external source voltages.

This isolation was introduced with the gen 5 cards and it was and remains very effective.

Just my 2¢ worth

JJ
 

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