Review and Measurements of Schiit Eitr USB to S/PDIF Bridge

[Wombat]

Run the words Schiit Eitr together. Eater or tighter, deliberate pun about their loyal customers?

 

[Final]

Not being sure which language is appropriate, the translation could be Klyster or Lavemang

Well Jotunheimen (land of giants) is a Norwegian mountain area. In Norwegian enema translates to klyster so I would vote for Schiit Klyster

 

[AntonK]

I was about to buy the Eitr, this review saved me from the mistake. Thanks!

 

[The Dragon]

Just hope they don't come out with a product called the Enema.

They probably won't as it doesn't fit with the Nordic mythos naming convention.

No, but jǫtunn - meinfretr does...

 

[Coop]

This is a review and detailed measurements of Schiit Eitr. It is a on a kind loan from the same member that provided me the the excellently performing iFi iDSD Black Edition. It retails for $179 plus shipping from Schiit direct (they don't sell through any other channel).

If you are not familiar with it, the Schiit Eitr is a USB to S/PDIF converter. Yes, Schiit DACs already have USB interfaces but the quality there is not what it should be. So Schiit took the design of their "Gen 5" USB interface from their higher-end units and is providing it in the form of an external USB to S/PDIF bridge/converter.

The Eitr comes in the same enclosure as Schiit Modi 2 series. Here you see it below my Schiit Modi 2 Uber which I used for this review and testing:
View attachment 13973

The unit is externally powered with a linear/transformer wall-wart.

I am sure you all are anxious to see how it measures and whether it improves on USB interface so let's get into that.

Measurements
Whenever I want to test some USB tweak, I go for the Schiit Modi 2 series of DACs because they are fair susceptible to USB vagaries, especially power. This makes it possible to see effects of such modane things as USB cables. The fact that it pairs up with Schiit Eitr visually and practically is a bonus here.

The weapon of choice when it comes to measurements is jitter and noise since we are changing one digital interface (USB) for another (S/PDIF). So let's look at that, comparing the USB input on Schiit Modi 2 Uber to when it is driven through Eitr to its S/PDIF input:
View attachment 13974

Focusing on the USB input on Modi 2 Uber, we see tons of issues there. We have deterministic distortion spikes in the form of those red vertical lines to the left. We also have some random repeating noise source that is causing that scalloping.

Using Eitr to drive Modi 2 Uber's S/PDIF input makes a substantial improvement. Noise floor is substantially lowered as are the distortion spikes.

On the negative side we have a couple of jitter/distortion spikes around our main tone we didn't have. They seem to be related to power supply section of Eitr as shown to the left of the graph with the blue arrow.

Alas, some of the core problems of Modi 2 Uber remain such as random noise that causes that wide skirt (our main tone in the middle needs to be a sharp spike). Whatever the source of that is, is not related to the digital input used.

Next I used my Audio Precision APx555 analyzer as the source, expecting to see even more improvement over Schiit Eitr but that was not meant to be!
View attachment 13975

Now this is a head scratcher. My $28,000 analyzer generates worse response with Modi 2 Uber than Eitr (light green)!!! Audio Precision does better by not creating those power supply related spikes that Eitr has but otherwise, the AP is having a poor showing. Or inversely, the Schiit Eitr is doing excellently!

To analyze what is going on, I used the APx555 to analyze the jitter spectrum of itself and that of Schiit Eitr over S/PDIF:
View attachment 13976

The APx555 analyzer redeems itself (in red) by having substantially cleaner signal than Schiit Eitr (in blue). The Eitr has higher noise as frequencies increase and importantly, has all of those deterministic spikes. It is a puzzle why when driving the Schiit Modi 2 Uber with these two sources, the reverse outcome shows up.

Let's try an alternative to Eitr in the form of Topping D10 DAC ($80). Even though the D10 is a DAC, it can also function as a USB to S/PDIF bridge. So let's see how that does when driving Schiit Modi 2 Uber versus Eitr (again, as a USB bridge only):
View attachment 13978

Wow, the D10 actually does a bit better! It has the same noise profile as the Schiit Eitr but is free of its power supply induced jitter around our main tone. That is because it doesn't have an external power supply and just re-filters USB power.

Let's switch gears and test a much higher performance DAC, the Topping D50 (retail around $250). Same test as before with comparison of its internal USB connection compared to Eitr driving its S/PDIF:



View attachment 13979

Very different outcome here. The USB input on the D50 has less substantially less noise as compared to driving it with Eitr through its S/PDIF input. Yes, there is a tiny bit of reduction in USB packet noise (at frequencies of 1 kHz and harmonics). But overall, Eiter takes us a step backward than forward.

Note that the worsening performance with Eitr is that likely the S/PDIF input on the Topping D50 is not as good as its asynchronous USB input.

I should mention that all of these are highly magnified measurements. I am using very high resolution FFT to get the spectrum and the display is zoomed vertically a lot by maxing out at -80 dB. Here is what it looks like when we change the scale vertically:
View attachment 13980

We see that the distortion spikes are at -115 dB or lower. So definitely not an audible concern. And hearing random noise is a tough thing in audio.

Conclusions
The Schiit Eitr does it what it says it does: it brings a much better USB interface to Schiit products than is available in their lower end offerings. It makes a significant improvement in the measured performance of Schiit Modi 2 Uber for example. It only has a tiny design flaw and that is the noise from its power supply.

The Topping D10 performs the same function at less than half the price but looks ugly as sin on top of any Schiit product. If you can hide it some place, then that won't be an issue. Then again, why not just use Topping D10 at the start instead of stack of Eitr with another Schiit DAC? I know, I know. I shouldn't ask these questions.

So overall, Schiit Eitr is recommended for Schiit lower-end DAC owners to get better measured performance.

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As always, questions, comments, recommendations, etc. are welcome.

If you like this review, please consider donating funds for these types of hardware purchases using Patreon (https://www.patreon.com/audiosciencereview), or upgrading your membership here though Paypal (https://audiosciencereview.com/foru...eview-and-measurements.2164/page-3#post-59054).

I need to connect a PC to a DAC that will require 25 feet of cable. Could I place a Schiit Eitr or a Topping D10 near the PC and then run 20 some feet of optical cable to the DAC? What would this sound like?

Thanks very much for your help.
Coop

 

[Veri]

I need to connect a PC to a DAC that will require 25 feet of cable. Could I place a Schiit Eitr or a Topping D10 near the PC and then run 20 some feet of optical cable to the DAC? What would this sound like?

Thanks very much for your help.
Coop

That should work yes. Just need a dependable cable.

 

[The Dragon]

I need to connect a PC to a DAC that will require 25 feet of cable. Could I place a Schiit Eitr or a Topping D10 near the PC and then run 20 some feet of optical cable to the DAC? What would this sound like?

Thanks very much for your help.
Coop

There are also some other solutions to this. There are a couple "black box" type USB DACs based on the TI PCM2704 chip that have an SPDIF Coax and optical output for connection to another DAC. bypassing the internal DAC. Very inexpensive solution.

For example the Signstek HiFi DAC

https://www.amazon.com/gp/product/B00FEDHHKE/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1

 

[Coop]

Thanks folks for your input. Which would sound better, the Topping D10 or the Signstek HiFi DAC? I'm a little concerned about the effect of the USB to optical conversion on the signal quality, especially since it then has to travel 8 meters (26') through an optical cable before it reaches my DAC. I like the fact that the Topping D10 was favorably reviewed here.

I'm sure it's apparent that I don't really know what I am doing so I can use all the help I can get. (Also, any recommendations for the type of optical and usb cable?)

Thanks very much.

Coop

 

[Jimster480]

Thanks folks for your input. Which would sound better, the Topping D10 or the Signstek HiFi DAC? I'm a little concerned about the effect of the USB to optical conversion on the signal quality, especially since it then has to travel 8 meters (26') through an optical cable before it reaches my DAC. I like the fact that the Topping D10 was favorably reviewed here.

I'm sure it's apparent that I don't really know what I am doing so I can use all the help I can get. (Also, any recommendations for the type of optical and usb cable?)

Thanks very much.

Coop

I would say that the D10 is the better choice because its performance is proven.

 

[don'ttrustauthority]

So basically their entire product stack is a scam ...

How is it a scam? They tell you the measurements. You can listen for 15 days, and ask for a return and you get 15 more days to return, so really you get a 30 day return. And if my experience with their service is an indication, I bet they'd refund 100% if you made a stink but were polite about how these inaudible distortions were a problem for your listening experience.

 

[MacCali]

They are discontinued and going for a 100 in the clearance b-stock section. I have nothing that shoots out coaxial so i'll buy it for fun, i'll use an external battery to power the unit and hopefully that will clean it up even more. Doubt there's going to be any major audible difference, but for a 100 why not. Everything coming out my PC

 

[don'ttrustauthority]

They are discontinued and going for a 100 in the clearance b-stock section. I have nothing that shoots out coaxial so i'll buy it for fun, i'll use an external battery to power the unit and hopefully that will clean it up even more. Doubt there's going to be any major audible difference, but for a 100 why not. Everything coming out my PC

Could save an expensive dac if you got sloppy hooking up a temporary usb one day.