Schiit Modi Multibit - No Love?

[Grattle]

"Misinformation" could be pointless claim without technical data or DBT to back it up. The fact you suggest the Multibit sounds better after warm-up may be one:

Plus, @amirm measured the Yggy before and after warm-up with absolutely no change seeable in measurements.

In fact I have. Succumbed to the hype. It's a peace of trash. Sold it after 2 weeks. That was before I was on this site. Fortunately there isn't a lack of deceived individuals wanting one out there, so no monetary loss was incurred,

So, are Amir's measurements wrong? According to them, you should hear no audible difference? Which is it? Can you really hear sounds at -90db?

 

[gvl]

So, are Amir's measurements wrong? According to them, you should hear no audible difference? Which is it? Can you really hear sounds at -90db?

Modi multibit is worse than -90dB.

 

[VintageFlanker]

Modi multibit is worse than -90dB.

Yep.

But SINAD is not the most fucked-up part:

That could be definitely audible.

 

[Grattle]

Modi multibit is worse than -90dB.

https://www.audiosciencereview.com/forum/index.php?threads/review-battle-of-schiit-audio-dacs.5487/

Not according tho those measurements. I can't find a single flaw that would be audible to a dog. Really, the same statement holds true to 99% of the dacs I've seen measured here. Most of the "problems" are relative and inaudible.

 

[Grattle]

Yep.

But SINAD is not the most fucked-up part:

View attachment 46773

That could be definitely audible.

You can hear differences with magnitude no greater than -70db?

 

[Grattle]

Modi multibit is worse than -90dB.

Please show me where and explain. I'd like to understand this better.

Thanks!

 

[gvl]

Please show me where and explain. I'd like to understand this better.

Thanks!

Look at the linearity graph. It goes off the rails at -72dB. It is unable to faithfully reproduce variations in signal that are lower than -72dB. Up to -100dB if not more is fair game.

 

[Grattle]

Look at the linearity graph. It goes off the rails at -72dB. It is unable to faithfully reproduce variations in signal that are lower than -72dB. Up to -100dB if not more is fair game.

I don't know much about what this measurement is telling us. To me, -72db seems like it would be below audibility.

Also, is this test run at a specific bit depth/sample rate?

 

[gvl]

I don't know much about what this measurement is telling us. To me, -72db seems like it would be below audibility.

Also, is this test run at a specific bit depth/sample rate?

Should be all here: https://www.audiosciencereview.com/forum/index.php?threads/understanding-audio-measurements.2351/

 

[nacc18]

I really don't think the science of how subjectively beautiful a sound is is anywhere close to being advanced enough for a company to be very deliberate and precise. I think it's more of a try a bunch of stuff till it sounds nice type of thing. I think the makers of ladder dacs have inherently different design philosophies. But I have never designed a multibit DAC, or interviewed someone who has about their design philosophy, so I am really just making assumptions here.

I do know that the guys at Schiit have been very vocal about not designing the modi multibit around it's measurements. They claim they already did that with the regular modi. They prefer the modi multibit because it sounds better to them. As for how precise they were in crafting the details of their multi-bit sound, I do not know.

I think it is worth keeping in mind that resistor ladder DACs are valued not for how accurately they measure but for how pleasantly they distort. They are basically the DAC version of a tube amp. The value of a tube is not in how close it can sound to a solid state but how pleasantly it can twist the sound to the listener's preference.

For this reason, I am of the opinion that measurements are actually quite useless in judging these types of products that are engineered toward subjective tonal and timbral preference instead of objective performance.

Hi @Noob - first off apologies if this is redundant; I scanned the thread but didn't notice someone making exactly the same point however my observational powers are sub obtimal.

Analog devices (ADI) makes the actual DAC inside the Yggdrasil, the AD5791.The AD5791 datasheet is here. They market this as an industrial / measurement DAC so they don't publish FFTs, but there are 3 main measurements that strongly indicate the ENOB/SINAD/SNDR (all the same measurement) would be basically ideal (within 1 LSB or 1 "bit" of the total 20), assuming one reproduces the same test conditions that ADI did when characterizing the part (looks like it prefers a fairly high and clean voltage supply, and given Schiit's stance on power supplies and @amirm finding AC mains spurs in the FFTs I wouldn't be surprised if the reference quality was the main problem).

Reason 1/3: On page 15/27, you'll see the output of the DAC fully settles to its final value under all measurement conditions within 1-1.5 microseconds. This means that it will work at any sampling rate below 500kHz - 1MHz. I can't find it now but I remember when reading about Schiit's proprietary filter that they do 8x oversampling (and their proprietary novelty is that every 8th sample is the original contained in the source), so if you're sending 44.1 - 96 kS/s data then the sampling rate is not the problem. Maybe there is settling-time related degradation with 192kS/s material.

Reasons 2 & 3: On page 9/27, you'll see INL and DNL measurements (Integrated Non Linearity and Differential Non Linearity; you can learn about them here starting on page 5.5). TLDR is if the DNL and INL are less than 1 LSB across the entire input range then you have succeeded in designing an N-bit converter; if you made an N-1 bit converter it would be worse.

To my knowledge none of the 24-bit converters actually measure 24 bits of ENOB. The best DACs @amirm has measured get between 20-21. The DAC chips (or ICs, integrated circuits) inside of them also only get about that, which means the engineers of DACs that measure 20-21 bits of ENOB like the topping D90 have succeeded in extracting all of the possible performance out of the DAC chip and have not ruined anything.

Finally, the AK4191EQ in the Topping D90 is a switched-resistor ("multibit") DAC, as they state in the first sentence of their product brief here, so if there was some fundamental flaw with switched resistor DACs preventing good measurements, this would be impossible.

Happy to address anything I've left out, and intent was just to shed some hopefully useful information about how data converters work and what all of these measurements mean.

 

[Boris Baron of Poor-Fi]

IIRC the Modi Multibit is a stripped down version of the Bifrost Multibit, which Amir already tested. It wasn't pretty.

https://www.audiosciencereview.com/...d-review-of-schiit-bifrost-multibit-dac.2319/

The biggest flaw of Amir's reviews is that they don't include actual music, and he ignores more audible forms of distortion. One can not simply judge an item based solely on theoretical measurements.

 

[maxxevv]

The biggest flaw of Amir's reviews is that they don't include actual music, and he ignores more audible forms of distortion. One can not simply judge an item based solely on theoretical measurements.

So how do you objectively measure with music then ?

A DAC is just a waveform processor. There are other devices down the line that will be needed to get its signals to your ears ..
- a headphone amp / power amp
- a pair of headphones / speakers

So how do you objectively compare when everybody else has different devices in that chain ?

 

[VintageFlanker]

The biggest flaw of Amir's reviews is that they don't include actual music,

How do you measure "music" with an Audio Precision? Do you actually believe that a DAC identifies incoming data as music? Turns out: it doesn't.

he ignores more audible forms of distortion

Would you explain what forms are you talking about?

One can not simply judge an item based solely on theoretical measurements.

Why is that? These are not "theoretical" at all.

 

[Grattle]

With your ears.

 

[Grattle]

Music is art. Art by its very nature is subjective. Try measuring the value of a painting objectively. We are not robots. If a piece of hardware reproduces the waveform beyond your ears ability to discern any differences than another piece of hardware, then they are effectively equivalent to humans.

 

[gvl]

With your ears.

Mine are not golden, so I don't trust them.

 

[curiouspeter]

I'm happy a company like Schiit will produce something different. Another choice for consumers can only be a good thing.

$250 is a very good price, although I would rather get the Bifrost 2 for $699. I actually considered that.

 

[dfuller]

The biggest flaw of Amir's reviews is that they don't include actual music, and he ignores more audible forms of distortion. One can not simply judge an item based solely on theoretical measurements.

Any sound can be decomposed into sine waves. Amir measures with 32 tones for "music" simulation (which is similar enough to work well enough) , and he also measures intermodulation distortion (much more easily audible than harmonic distortion). He checks filters and THD+N vs frequency as well.

Finally, the AK4191EQ in the Topping D90 is a switched-resistor ("multibit") DAC, as they state in the first sentence of their product brief here, so if there was some fundamental flaw with switched resistor DACs preventing good measurements, this would be impossible.

The D90 uses an AK4499, not a 4191. Anyway, the issue with R2R DACs that don't incorporate a D-S modulator somehow (modern ones are multibit D-S hybrids) is that you are entirely dependent on resistor accuracy for accurate reproduction. To do so accurately to 16 bits requires resistors of incredible precision (0.001%) - and that's really only doable if you print the resistors directly on the silicon and laser trim them for accuracy. But, a 4-5 bit multibit D-S DAC like most modern ESS, Cirrus Logic, Analog Devices, or AKM designs sidestep the issues of both 1-bit D-S DACs (namely, lots of noise) and purely R2R DACs (generally garbage low level fidelity).

Also, is this test run at a specific bit depth/sample rate?

Unless otherwise specified it's at 24 bits, 44.1k as far as I'm aware.

 

[bilzebubba]

Not knowing about the MultiBit's, er, "pedigree" I'll admit to owning one (bought used off of someone who probably joined ASR before I did...wasn't cheap! So my question is, just how bad is it, for those who've compared it in blind listening (if anyone). I I DO like how it at least produces silence when turning on, unlike one of my (older) Toppings and my Matrix...

 

[Veri]

I I DO like how it at least produces silence when turning on, unlike one of my (older) Toppings and my Matrix...

What do you mean by this exactly?