Review and Measurements of Schiit Yggdrasil V2 DAC

[Blumlein 88]

Ugh! So I think we need to close this to comments again now.

 

[Blumlein 88]

Back on topic while I can.......

So Amir are you going to show us those unmeasurable bits that happen during 7 day warm up to improve the sound?

 

[amirm]

Is it possible to send a properly dithered 20-bit signal at high and low level (e.g. -1dB and -90dB) and compare with the same 24-bit signal and show the FFT? Basically I would like to see how it performs without truncation artifacts.

Now, that is a smart suggestion! Here are the results:

As suspected, there is signal processing error in conversion of 24 bit to a 20 bit PCM DAC used in Yggdrasil. The 20 bit samples definitely look cleaner and only have harmonic distortion and at lower amplitude. The 24-bit reproduction is clearly inferior with a lot more anharmonic content and higher distortion spikes.

Yes, the noise floor is higher for 20 bit but that is benign and comers with territory (of using lower resolution).

 

[garbulky]

Now, that is a smart suggestion! Here are the results:

View attachment 13692

As suspected, there is signal processing error in conversion of 24 bit to a 20 bit PCM DAC used in Yggdrasil. The 20 bit samples definitely look cleaner and only have harmonic distortion and at lower amplitude. The 24-bit reproduction is clearly inferior with a lot more anharmonic content and higher distortion spikes.

Yes, the noise floor is higher for 20 bit but that is benign and comers with territory (of using lower resolution).

Have you tried the 1 khz measurement to see if it is still off by that 0.00008 number using a 20 bit signal? What is the linearity of the -90 db test using 20 bit? What kind of probloem with the signal processing do you think is causing this 24 bit distortion?

 

[Blumlein 88]

Now, that is a smart suggestion! Here are the results:

View attachment 13692

As suspected, there is signal processing error in conversion of 24 bit to a 20 bit PCM DAC used in Yggdrasil. The 20 bit samples definitely look cleaner and only have harmonic distortion and at lower amplitude. The 24-bit reproduction is clearly inferior with a lot more anharmonic content and higher distortion spikes.

Yes, the noise floor is higher for 20 bit but that is benign and comers with territory (of using lower resolution).

Looks like you need to rerun all the tests using 20 bit input.

Of course the Yggy was meant to perform the best with the real music you have, which is mostly CD. 16 bit CD signal is fine. Its a feature not a bug.

And once again flaky lackadaisical engineering. If the device is 20 bit, and running 24 bit signals causes truncation or other issues, then the device should internally convert 24 bit input to 20 bit input for the DAC chip to get better performance. I'm telling you this company is just rubbing people's faces into it. And you know what 'it' is.

 

[amirm]

Have you tried the 1 khz measurement to see if it is still off by that 0.00008 number using a 20 bit signal?

I haven't but I am pretty sure that is not changed.

What is the linearity of the -90 db test using 20 bit?

I measured linearity but did not save it. It definitely changes from those up/down owings to a more gentle error.

What kind of probloem with the signal processing do you think is causing this 24 bit distortion?

They need to dither (add noise) prior to conversion to 20 bits. Simple truncation causes problems. It is shocking to see a digital DAC designer not know about this core principle of signal processing but that is what the facts point to.

 

[Thomas savage]

Ugh! So I think we need to close this to comments again now.

Reply ban issued to member @Thomas savage

I’m sorry.

 

[Wombat]

Reply ban issued to member @Thomas savage

I’m sorry.

Undie washing day:

 

[amirm]

That's a riot....

 

[gvl]

If memory serves they were pretty upfront about the truncation. Sounds like a recommendation upgrade is in order for CD playback? The bad news for hi-res is that 20 bit real time dither is not always available in players. I guess one could run their hi-res library through SoX dithering to 20 bits, but it's a pita.

 

[bennetng]

Now, that is a smart suggestion! Here are the results:

View attachment 13692

As suspected, there is signal processing error in conversion of 24 bit to a 20 bit PCM DAC used in Yggdrasil. The 20 bit samples definitely look cleaner and only have harmonic distortion and at lower amplitude. The 24-bit reproduction is clearly inferior with a lot more anharmonic content and higher distortion spikes.

Yes, the noise floor is higher for 20 bit but that is benign and comers with territory (of using lower resolution).

Thanks. I guess this screenshot made some readers believe that all of the spikes are power supply noise and subsequently suggested a cleaner power supply, even though the text is on left hand side.

Digital distortion (right) can only be cured by DSP, and in this case dithering.

 

[Blumlein 88]

If memory serves they were pretty upfront about the truncation. Sounds like a recommendation upgrade is in order for CD playback? The bad news for hi-res is that 20 bit real time dither is not always available in players. I guess one could run their hi-res library through SoX dithering to 20 bits, but it's a pita.

I'd be pretty up front that for more than $2000 I would avoid the pain in the a** and buy a superior RME DAC for less than half price. A modern DAC of less than 24 bits that truncates is a total design failure. Completely unnecessary unless it is SCHIIT!

And no, the designers aren't ignorant of the fact. I tell you they are rubbing everyone's face into it and laughing all the way to the bank.

 

[gvl]

We need measurements with dithered signal to better understand redbook performance. Personally I don't care about hires.

 

[DonH56]

We need measurements with dithered signal to better understand redbook performance. Personally I don't care about hires.

I have not really been following, but how is adding dither to the signal before the DAC useful? Your CD player is not going to add dither to the digital bitstream, that is up to the DAC, and if the DAC does not do it why bother testing an unrealistic scenario? I must have missed or misunderstood something, sorry...

Truncating will add a low-level harmonic spray. Since it is at the lsb level of the signal (more or less), it should be inaudible, but certainly makes the measurements look much worse. Even if I don't think I can hear it, since there are so many other options, why buy something subpar?

 

[derp1n]

Is Amir wasting his time measuring (another) broken Yggdrasil?

At least the special Yggdrasil "Reviewer Edition" they send out measures well.

 

[έχω δίκιο]

We need measurements with dithered signal to better understand redbook performance. Personally I don't care about hires.

I see no reason to test whether this expensive DAC might perform adequately in some limited use case. Since the existing measurements have already established that it is poorly engineered, no one should buy it. People with $2,399 to spend on a DAC should be giving their money to reputable companies, like Benchmark, that consistently produce top-quality products. That's the kind of company that we want to survive in this market space.

 

[Jinjuku]

And no, the designers aren't ignorant of the fact. I tell you they are rubbing everyone's face into it and laughing all the way to the bank.

That's always been my alternate explanation that they are simply throwing their hands up in the air and giving the gullible exactly what they are willing to pay for.

It's immoral to let a sucker keep their money.

 

[gvl]

I want to at least see linearity results using dithered signal, this would provide some insight into how the DACs cope with interpolated samples, assuming Schiit digital filter produces 20bits on its output from 16 bits.

 

[amirm]

I want to at least see linearity results using dithered signal, this would provide some insight into how the DACs cope with interpolated samples, assuming Schiit digital filter produces 20bits on its output from 16 bits.

???

Here is the comparison of 16 bits versus 24 bits:

The noise floor jumps up by 30 dB when using 16 bit samples. Is this what you were asking about?

 

[έχω δίκιο]

Here is the comparison of 16 bits versus 24 bits:
{plot deleted for brevity}
The noise floor jumps up by 30 dB when using 16 bit samples. Is this what you were asking about?

It's a variation on the 'infinite monkeys' theorem. If you conduct an infinite number of tests on an infinite number of Schiit DACs, eventually one of the tests will show the DAC accurately converting the digital input to analog.