Schiit Yggdrasil (Unison USB) vs T+A DAC 8 DSD - mini review

[Gavin1977]

This is my second mini-review.  Last time around I reviewed the Mola Mola Tambaqui vs T+A DAC 8 DSD.  Once again please see my profile for a full description of my system.  For this review I ran the Yggdrasil (Yggy) using the bit perfect volume control in HQPlayer (no preamp used).

 

It’s very easy to get carried away by this DAC.  Decay, pitch and tone and all great on the Yggy.  But it’s the Yggy’s skills with the decay of musical notes which I like the best.  It creates lucidity, and to some extent also helps deliver greater realism compared to the delta-sigma DAC’s that I’ve heard (the T+A DAC 8 DSD and the Chord DAVE I also tested).

 

I perceive the delta-sigma DAC’s I’ve heard as having too little decay and sounding comparatively unnatural and ‘quantized’ as a result.  Perhaps the improve decay of the Yggy is a general attribute of the multi-bit approach, and the improved realism is a consequence of removing the standard digital filtering approaches found in delta-sigma DACs.   I cannot say for sure as this is the only multi-bit DAC I have heard, but this is my hunch.  The Yggy definitely has a more natural interplay between different parts of the music, and a natural flow.   If this is what a lack of a traditional digital filtering does, then I like it… a lot.

 

Yggy only plays PCM - fine by me!  I also tried feeding it upscaled PCM from HQPlayer (closed form and Sinc-M), but I still preferred the sound of the Yggy feeding it unaltered redbook 44.1k files.  There is no need to use HQPlayer with the Yggy.

 

I think Yggy could be wonderful for headphone listeners - it has great stereo separation, and that ’90’s style Walkman ((((Surround)))) effect.

 

The Yggdrasil can also brighten up a darker sounding set-up nicely. Perhaps my set-up is a little ‘dark’.   This slightly brighter top end helps retrieve detail and adds air.  The effect of adding the Yggy to my system could also be compared to when you have two versions the same speaker and one has the better tweeter (or super tweeter added), it just helps fill in the sound that bit better throughout the entire frequency range.  It benefitted my system most on acoustic and orchestral tracks.

 

In comparison the T+A DAC 8 DSD that I have sounds digitally squeaky clean (remember the first time you heard the Pet Shop Boys on CD?), and music just doesn’t coalesce as well.  T+A DSD 8 DSD doesn’t do natural decay as well.  The T+A is pasteurised.  The Yggy is a 21’s century Sony Walkman in comparison.  Presentation is otherwise very similar between both of these DACs, they both have presence and bring performances into your living room.

 

Now faults of the Yggy…  I think it’s let down by the quality of the power supply.  Yes the Yggy’s topology of two transformers (one for digital supplies, one for analog supplies) is ideal, but the transformer types are not classic donut toroidal and the regulators used are LM723.  Not bad, but performance can be pushed further with newer regulators / parallel regs.  You can hear hum from the transformers in the power supply section from 1-2 feet away. I do strongly believe that this audible hum affects measured performance as well.  Audio Science Review have shown this in their results, which gives some grounding to what I am hearing as well.  Background of the Yggy (Sony tape Walkman) is not as black as that of the T+A DAC 8 DSD (CD Player).

 

So, I would absolutely love to own a Schitt Yggy - their approach to true multi-bit, the quality of the analogue outputs, their Unison USB implementation are all absolutely amazing.  I just think it needs a better power supply then it would be an 'uber DAC'.  I would definitely look to purchase the Yggy if the next upgrade in its lifecycle is an improved power supply.  I would then rank it as preferable to the T+A DAC 8 DSD (when fed DSD from a higher quality HQPlayer server).

 

Next up...  ECDesigns Fractal DAC.  It's been delivered, I'm just waiting for my new pre-amp to arrive so I can run it.

[AudioDoctor]

I am slightly interested in the hum you heard. Did you try anything to mitigate it, or figure out if there was a ground loop of some sort (or similar) causing it? Perhaps it is my ear ringing drowning out any noise from my Yggy but I don't hear a thing from it. AS far as the rest of your review goes, I agree, I find the Yggy a really great, musical DAC and enjoy listening to it.

[Gavin1977]

I don’t think it’s a ground loop issue, the humming is not obvious upon first switch on, but becomes apparent if the unit is left on continuously.  Hum is never heard through the loudspeakers, but the noise floor of the Yggdrasil is not as low as the T+A DAC 8 DSD.  It’s my assumption that if you can hear transformer hum local to the DAC, then that will affect performance (e.g noise floor).

 

The voltage here at my house is actually more like 242v, it’s runs hot compared to the UK 230v standard.  Perhaps the transformers in the Yggdrasil work better at 230v.

[Jeff_N]

Until recently when I swapped it out for a different reason, I always left my Yggy turned on and I never heard a hum. Maybe my system isn't as good as yours.

 

Interesting comparative review anyway.

[AudioDoctor]

I also leave mine on and I never hear a hum. Your power may have something to do with that.

[Dr Tone]

No hum with mine.  I’ve compared it it to the exceptionally quiet Mirus Pro Signature.

[GUTB]

My Yggdrasil Analog 2 doesn't emit a loud hum. Mind you it's plugged into an balanced isolation transformer.

[Gavin1977]

5 hours ago, Dr Tone said:

No hum with mine.  I’ve compared it it to the exceptionally quiet Mirus Pro Signature.

Just to be clear there is no hum through my speakers.  This is a quiet DAC, just that the noise floor isn’t as low as my T+A.

 

All of my equipment is attached through a filtered mains block.

 

I’m not sure an isolation transformer would resolve the issue, main reason that the hum from the physical unit itself isn’t present when first powered.

[matthias]

17 hours ago, Gavin1977 said:

For this review I ran the Yggdrasil (Yggy) using the bit perfect volume control in HQPlayer (no preamp used).

 

Next up...  ECDesigns Fractal DAC.  It's been delivered, I'm just waiting for my new pre-amp to arrive so I can run it.

 

 

Very curious about the ECD, so is it not possible to run the ECD DAC in the same way without preamp as well?

Thanks

 

Matt

[blue2]

3 hours ago, Gavin1977 said:

Just to be clear there is no hum through my speakers.  This is a quiet DAC, just that the noise floor isn’t as low as my T+A.

 

All of my equipment is attached through a filtered mains block.

 

I’m not sure an isolation transformer would resolve the issue, main reason that the hum from the physical unit itself isn’t present when first powered.

A bit of Googling may help:

1 A cheaply designed transformer with unduly high magnetic field levels
2 DC on the mains, which has a vastly disproportionate effect in moving the magnetic circuit asymmetrically towards saturation
3 Unduly high mains voltage
4 Transformer designed for 60Hz being used on 50Hz
5 Transformer inadequately (or barely adequately) rated for the load
6 Transformer badly assembled with insufficient glue

 

https://forums.audioholics.com/forums/threads/getting-rid-of-transformer-hum.3879/

[Gavin1977]

57 minutes ago, matthias said:

 

Very curious about the ECD, so is it not possible to run the ECD DAC in the same way without preamp as well?

Thanks

 

Matt

Nope - uses SPDIF/Electrotos.  Volume control is not available through this.

[Gavin1977]

45 minutes ago, blue2 said:

A bit of Googling may help:

1 A cheaply designed transformer with unduly high magnetic field levels
2 DC on the mains, which has a vastly disproportionate effect in moving the magnetic circuit asymmetrically towards saturation
3 Unduly high mains voltage
4 Transformer designed for 60Hz being used on 50Hz
5 Transformer inadequately (or barely adequately) rated for the load
6 Transformer badly assembled with insufficient glue

 

https://forums.audioholics.com/forums/threads/getting-rid-of-transformer-hum.3879/

May well be a combination of things: my locally high voltage, Schitt using chassis mount transformers vs traditional toroidal (although there is some talk that EI transformers can actually perform better in this application).  Unlikely to be DC on the mains as I have no issues elsewhere and the Yggy is also fitted with a mains IEC filter.

 

The lower transformer used in the Yggy looks like a https://mcitransformer.com/product/mci-4-014-02-series/

 

Either way, I would call it an inherent weakness of the Yggy, shame as I think everything else is great.  

 

I actually looked at the ASR website after I'd finished the bulk of my listening, but I think there is some truth in the measurements:  https://www.audio “science” review/forum/index.php?threads/measurements-and-review-of-schiit-yggdrasil-dac.2358/

[Norton]

20 hours ago, Gavin1977 said:

Next up...  ECDesigns Fractal DAC.  It's been delivered, I'm just waiting for my new pre-amp to arrive so I can run it.

Which ECD transport/interface will you be using it with?  From my experience the UPL gives notably better results than the U192, so much so that, IMV, the Fractal/UPL should be considered as a single entity.  In the main I’m not a HP listener, but the Fractal/UPL via HPs really demonstrates what they can do in terms of clarity, detail, lack of grain vs any other digital front end I’ve owned  or spent time with.

[JoeWhip]

My guess is that when the next Yggy update is released, it will have an improved power supply, which may result is a larger chassis. Just my supposition though.

[Gavin1977]

1 hour ago, Norton said:

Which ECD transport/interface will you be using it with?  From my experience the UPL gives notably better results than the U192, so much so that, IMV, the Fractal/UPL should be considered as a single entity.  In the main I’m not a HP listener, but the Fractal/UPL via HPs really demonstrates what they can do in terms of clarity, detail, lack of grain vs any other digital front end I’ve owned  or spent time with.

U192 as I like the convenience of streaming

[Exocer]

16 hours ago, Jeff_N said:

Until recently when I swapped it out for a different reason, I always left my Yggy turned on and I never heard a hum. Maybe my system isn't as good as yours.

 

Interesting comparative review anyway.

I'm with you - there is no audible hum from my Yggy as well.

[ssh]

My Yggy is dead quiet.

[Exocer]

@Gavin1977,Thanks for sharing your thoughts on the Yggy. May I ask how old this particular Yggy is? Some will debate this but after about 10 days the sound improved quite a bit. I keep my Yggy on 24/7 but I do not think I was able to experience what it was truly capable of until at least 10-11 into owning it. Cheers

[realDHT]

7 hours ago, Gavin1977 said:

Nope - uses SPDIF/Electrotos.  Volume control is not available through this.

I never used HQ Player, but I have used the 64 bit internal volume control in JRiver MC with the U192 and Fractal DAC and that works very nicely. Why would the HQP volume not work? Not bitperfect but I would guess still more transparent than adding a preamp. Looking forward to hear about your listening impressions.  

[Gavin1977]

1 hour ago, Exocer said:

@Gavin1977,Thanks for sharing your thoughts on the Yggy. May I ask how old this particular Yggy is? Some will debate this but after about 10 days the sound improved quite a bit. I keep my Yggy on 24/7 but I do not think I was able to experience what it was truly capable of until at least 10-11 into owning it. Cheers

The Yggy I reviewed was purchased new and had a total of two weeks 24/7 burn in before critical listening.

[Gavin1977]

Perhaps I could also add that the noise floor of the Yggy was also not as low as a topping D90 I also had in recently.

 

Yes you shouldn’t hear any hiss/hum through your loudspeakers - I certainly didn’t - I’m not suggesting that.

 

But I perceive the noise floor as not being as low as either the T+A, Chord Dave or Topping D90 I had in.

 

The hum I have from my unit could well have been from the local voltage being somewhat high.

[Gavin1977]

29 minutes ago, realDHT said:

I never used HQ Player, but I have used the 64 bit internal volume control in JRiver MC with the U192 and Fractal DAC and that works very nicely. Why would the HQP volume not work? Not bitperfect but I would guess still more transparent than adding a preamp. Looking forward to hear about your listening impressions.  

Ohh... that’s interesting.  I always thought that volume control couldn’t be undertaken through SDPIF.  Thanks for sharing.

[matthias]

3 minutes ago, Gavin1977 said:

Ohh... that’s interesting.  I always thought that volume control couldn’t be undertaken through SDPIF.  Thanks for sharing.

 

If HQP VC works with ECD will we get the review before your preamp arrives?

 

Matt

[Gavin1977]

Indeed 🤪

[Mark V.]

9 hours ago, matthias said:

 

Very curious about the ECD, so is it not possible to run the ECD DAC in the same way without preamp as well?

Thanks

 

Matt

The ECD Fractal has max output voltage of 1.27 V RMS, if your power amp has a lot of gain this could work, but most power amps do need more. In my setup I would definately need a pre amp with the Fractal DAC... Which is one reason which holds me back from buying it...