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Measurement and Review of Schiit BiFrost Multibit DAC

Thomas savage

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Maybe instead of saying you would never listen to such a DAC, you actually did listen and you did not hear anything that would lead you to believe it really measures that badly? Do you trust your ears at all? 10bit rez? such bad distortion? You think you might hear something? Maybeeee?
I did not say that.

That’s enough distraction @rebbiputzmaker , please refrain from posting in this thread unless you have something constructive to add.. data that is not word salad and / or memes ..

Cheers
 

March Audio

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More measurements by AtomicBob who is the person who also posted their measurements to Head-Fi that I linked too earlier.

http://www.superbestaudiofriends.or...aner-program-unit-technical-measurements.610/

As I have said. This should not turn into an accusatory schiitshow.
Well one question I have about those measurements is the dynamic range quoted. The graph shows a fundamental at -60dB. So this means the spurious free dynamic range is 40dBc as the highest spuria is about -100dB. If the test signal was raised to 0dBfs the distortion products would rise significantly. Ok I dont know exactly how much, but is difficult to imagine them being lower than -93 dB. So Im afraid I question that measurement result.
 

rebbiputzmaker

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I did not say that.

That’s enough distraction @rebbiputzmaker , please refrain from posting in this thread unless you have something constructive to add.. data that is not word salad and / or memes ..

Cheers
"Iv no intrest in anyone’s listening impressions of a dac That has 10bits of resolution."

Excuse me if I misinterpreted your comment.

Please try and not be too hypercritical as your multi-temp frozen schiit comments etc. were somewhat less that technical also.

(Moderator edit , yes but I’m not calling the data wrong or implying members like Cosmik are wrong in their assertions. If you want to challenge technical content do so in kind.

Hand waving does not count though I do appreciate your humorous intentions.

Cheers )

thank you
 
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rebbiputzmaker

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Just posted. From another board.

"Hey guys,



No clue what they're measuring, since their measurements don't correlate with our own (on Stanford SR1/SR1+ and Avermetrics Averlab). Nor do they correlate with other measurements posted by another audio engineer, AtomicBob on Head-Fi and SBAF. He actually measured two Bifrost Multibits:



http://www.superbestaudiofriends.org/index.php?threads/schiit-bifrost-mb-technical-measurements.235/

http://www.superbestaudiofriends.or...aner-program-unit-technical-measurements.610/



Bob's conclusion was different than ASR:



Excellent channel matching, even in the distortion measurements
Jitter is close, though not quite as excellent, as Gungnir MB
Listening evaluation to note multibit magic of dimension and depth present
Incedible performance for a 16 bit resolution DAC



Also, he measured some of our other DACs:



http://www.superbestaudiofriends.org/index.php?threads/schiit-modi-mb-technical-measurements.2603/

http://www.superbestaudiofriends.org/index.php?threads/schiit-gungnir-mb-measurements.414/

http://www.superbestaudiofriends.org/index.php?threads/schiit-yggdrasil-measurements.413/



Hopefully this helps a bit. Beyond that, DAC questions should be addressed to Mike Moffat, as I'm the analog guy.



All the best,

Jason"
 

Cosmik

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Just posted. From another board.

"Hey guys,



No clue what they're measuring, since their measurements don't correlate with our own (on Stanford SR1/SR1+ and Avermetrics Averlab). Nor do they correlate with other measurements posted by another audio engineer, AtomicBob on Head-Fi and SBAF. He actually measured two Bifrost Multibits:



http://www.superbestaudiofriends.org/index.php?threads/schiit-bifrost-mb-technical-measurements.235/

http://www.superbestaudiofriends.or...aner-program-unit-technical-measurements.610/



Bob's conclusion was different than ASR:



Excellent channel matching, even in the distortion measurements
Jitter is close, though not quite as excellent, as Gungnir MB
Listening evaluation to note multibit magic of dimension and depth present
Incedible performance for a 16 bit resolution DAC



Also, he measured some of our other DACs:



http://www.superbestaudiofriends.org/index.php?threads/schiit-modi-mb-technical-measurements.2603/

http://www.superbestaudiofriends.org/index.php?threads/schiit-gungnir-mb-measurements.414/

http://www.superbestaudiofriends.org/index.php?threads/schiit-yggdrasil-measurements.413/



Hopefully this helps a bit. Beyond that, DAC questions should be addressed to Mike Moffat, as I'm the analog guy.



All the best,

Jason"
Maybe the room temperature was different.
 

Cosmik

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And they still have that amazingly musical performance on the -90dB sine wave and the huge musical glitches on the -70dB.
index.php

index.php
 

Blumlein 88

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Okay I would wonder about the spiky noise floor not apparent in Bob's measures. If you reduce levels a dB do they go away?

Also dynamic range, spurious free range and snr are measured differently. Dynamic range is a -60 dB signal notched out and the residual vs 0 dbfs. I don't remember if Bob's result took into account fft gain. Bob shows the same poor linearity.
 

Frank Dernie

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The -70dB sine wave in Atomic thingies measurements are crap. The -90dB isn't even remotely like a sine wave, so the 10-bit linearity Amir measured is entirely plausible IMO.
OTOH LPs have about 10-bit resolution too and they can sound nice when well mastered.

This thread reminds me of the conclusion proposed by one reviewer but not answered by him when he gave a glowing review to a very expensive product which his measurements showed to be miles from accurate "Does it sound good despite the poor technical performance or because of it?"
Personally I suspect the latter since so many inaccurate pieces of kit get glowing subjective reviews, leading me to believe that a lot of people enjoy the distortion and noise added by things like this, LPs and some valve electronics.

I hugely value this forum, and rarely bother with any of the others any more, since on them HiFi seems to be completely lost.
 

Candlesticks

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I hope that AtomicBob isn't just going to be smug and offer more than you're doing it wrong but I'm not going to give any explanation. If not he is living up to the SBAF name.

rXICLph.png


CSpirou is incorrect. The difference in jitter was a result of Marvey using a Wyrd in between the computer and Modi 2. None of the others tested by Amirm such as the Fiio E10k were affected by the USB port used. Just the Modi 2.

I don't think AtomicBob has explained why the previous Modi 2 measurements were wrong.

Just posted. From another board.

"Hey guys,



No clue what they're measuring, since their measurements don't correlate with our own (on Stanford SR1/SR1+ and Avermetrics Averlab). Nor do they correlate with other measurements posted by another audio engineer, AtomicBob on Head-Fi and SBAF. He actually measured two Bifrost Multibits:



http://www.superbestaudiofriends.org/index.php?threads/schiit-bifrost-mb-technical-measurements.235/

http://www.superbestaudiofriends.or...aner-program-unit-technical-measurements.610/



Bob's conclusion was different than ASR:



Excellent channel matching, even in the distortion measurements
Jitter is close, though not quite as excellent, as Gungnir MB
Listening evaluation to note multibit magic of dimension and depth present
Incedible performance for a 16 bit resolution DAC



Also, he measured some of our other DACs:



http://www.superbestaudiofriends.org/index.php?threads/schiit-modi-mb-technical-measurements.2603/

http://www.superbestaudiofriends.org/index.php?threads/schiit-gungnir-mb-measurements.414/

http://www.superbestaudiofriends.org/index.php?threads/schiit-yggdrasil-measurements.413/



Hopefully this helps a bit. Beyond that, DAC questions should be addressed to Mike Moffat, as I'm the analog guy.



All the best,

Jason"

Note that all he actually does is point to AtomicBob's measurements and AtomicBob's subjective vouching for the amazing multibit sound which isn't even necessary to include. I'd love to see Schiit's internal measurements but that's not likely to happen. Maybe Schiit should put out a document on how to properly test multibit because it seems to fail with test signals. Perhaps if you measure it in just the right way it won't faceplant.
 
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Thomas savage

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I hope that AtomicBob isn't just going to be smug and offer more than you're doing it wrong but I'm not going to give any explanation. If not he is living up to the SBAF name.

rXICLph.png


CSpirou is incorrect. The difference in jitter was a result of Marvey using a Wyrd in between the computer and Modi 2. None of the others tested by Amirm such as the Fiio E10k were affected by the USB port used. Just the Modi 2.



Note that all he actually does is point to AtomicBob's measurements and AtomicBob's subjective vouching for the amazing multibit sound which isn't even necessary to include. I'd love to see Schiit's internal measurements but that's not likely to happen. Maybe Schiit should put out a document on how to properly test multibit because it seems to fall flat on it's face every time with test signals.
Oh well, I think some of them might be looking at the squiggly lines and not the numbers , the emotiva did not measure so badly to suggest all our measurements are wrong.. it might of looked that way when compared to the reference dac amir uses.

So if you just look at the pictures and don’t really understand what the data points to ..

It’s funny how the guys making the topping kit aren’t here saying amir can’t measure dac’s :D
 
OP
amirm

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Question:

What's the low level sine look like?
Here you go. This is after "warming up" the unit overnight.

Schiit BiFrost Multibit DAC -90 db sine wave measurement.png


We see massive glitching in Schiit BiFrost Multi-bit on the left. There is also channel imbalance in that the yellow and cyan graphs are at different levels (one is left, the other right channel).

Compare that to that of Topping DX7. The two channels land on top of each other as they should and we have a pretty good resemblance to a sine wave.
 
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amirm

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Here are the results of yesterday compared to the unit after being left on overnight:

Schiit BiFrost Multibit DAC Linearity Test after warm-up.png


As we see, there is no difference to speak of. And the unit itself feels the same temp as last night. Nothing is "warming up" from the outside anyway.
 

RayDunzl

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Experiment:

Room ambient: 54dB LZeq registers on the meter, 35.9 LAeq

Little Woman talks on Phone, 62dB Lzeq registers on the REW SPL meter.

Play TV (it's what's on right now here) at loudish levels, which might be selected for music listening.

upload_2018-2-6_12-3-38.png


Turn the TV down to -70dB with DSP.

Whatever remains is inaudible at the listening position (currently sitting in front of the PC behind and to the right of the sofa).

Bring the level to -60dB. All but inaudible. Occasional sound noted.

Bring the level to -50dB. Something audible, but unintelligible.

Bring the level to -40dB. Audible as someone talking, but still unintelligible. A few words come through, particularly if I turn around and add lip-reading.

Bring the level to -30dB. Intelligible unless there is some other noise (microwave in the kitchen drowns it out right now).

Bring the level to -20dB. Normal low level listening. Like you might choose to initiate a nap.

Bring the level to -10dB. Normal listening level for right-wing wacko and financial news.

Bring the level to -0dB. Waits for Little Woman to say "Too loud!"

Conclusion:
Assuming the high level stuff isn't too badly stuffed, it can "sound good", even if the low level goods are fugly.
 

Sal1950

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Duh I don't know. Maybe because the first word in the name of this place is AUDIO?
Do you chose to ignore the second two words. Science Review
the meadurements
Ideally yes I agree but Iv tried that and you end up being accused of censorship aimed at protecting “faulty” measurements and saving face and that hurts the validity of what we are doing .
Agreed, but we can only allow the threads to be cluttered so much with the usual audiophool BS.
" We don't need no stinkin meadurements, all we care about is how it sounds under totally uncontrolled and biased circumstances."
"It's written all over the net it sounds better with extended breakin."
ETC ETC ETC.
We've heard it all a million times before, once more per thread is more than enough. ;)
 
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amirm

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No clue what they're measuring, since their measurements don't correlate with our own (on Stanford SR1/SR1+ and Avermetrics Averlab). Nor do they correlate with other measurements posted by another audio engineer, AtomicBob on Head-Fi and SBAF. He actually measured two Bifrost Multibits:

http://www.superbestaudiofriends.org/index.php?threads/schiit-bifrost-mb-technical-measurements.235/
Thanks for posting that. As to what Schiit is saying, they should release their measurements if they have them instead of pointing to someone else's.

As to measurements posted there, they need to be equalized to parameters I am using to compare them. Here is the linearity test they ran with my notations:

Schiit BiFrost Multibit DAC Linearity Test from SBF.png


Here they used much larger vertical scale than I used. My scale came from Audio Precision by the way. Put a pin in that for moment and let's look at the measurement they provided. We see that there is a deviation starting in the middle of the graph. If you use my metric of 0.1 db variation as the limit, it falls in the same range of -58 db or so that I measured as far as cut off. So we are pretty consistent there.

If we move over to the limit of 16 db signal around -96 db, we see that there is over 10 db of error in their measurement clearly indicating that this DAC cannot reproduce 16 bit signals.

Here are my measurements in comparison after changing the vertical scale to match theirs:

upload_2018-2-6_9-22-52.png


We see good similarity at high level. They show a sudden drop around -70 db and mine does the same thing.

At smaller values my trough is deeper than theirs around -96 dB. That could very well be due to sample to sample variations or design changes along the way that are not publicized.

They show a larger error at -120 dB but both his and mine show awful performance there due to use of 16 bit DACs anyway.

Bottom line, both measurements are consistent and paint a rather ugly picture. I don't know how the Schiit folks think the SBF measurements are something good to point at when it shows such larger linearity error.

What is the point of a DAC if it doesn't output what you ask it in its input???

Again I welcome Schiit posting their measurements and we can do the same analysis. And if they think there is something wrong with mine, they should send me a sample to test.
 

rebbiputzmaker

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Experiment:

Room ambient: 54dB LZeq registers on the meter, 35.9 LAeq

Little Woman talks on Phone, 62dB Lzeq registers on the REW SPL meter.

Play TV (it's what's on right now here) at loudish levels, which might be selected for music listening.

View attachment 10384

Turn the TV down to -70dB with DSP.

Whatever remains is inaudible at the listening position (currently sitting in front of the PC behind and to the right of the sofa).

Bring the level to -60dB. All but inaudible. Occasional sound noted.

Bring the level to -50dB. Something audible, but unintelligible.

Bring the level to -40dB. Audible as someone talking, but still unintelligible. A few words come through, particularly if I turn around and add lip-reading.

Bring the level to -30dB. Intelligible unless there is some other noise (microwave in the kitchen drowns it out right now).

Bring the level to -20dB. Normal low level listening. Like you might choose to initiate a nap.

Bring the level to -10dB. Normal listening level for right-wing wacko and financial news.

Bring the level to -0dB. Waits for Little Woman to say "Too loud!"

Conclusion:
Assuming the high level stuff isn't too badly stuffed, it can "sound good", even if the low level goods are fugly.

A valid discussion might be what is actually addible and what is not. Also what is more important to sound quality? Do you trade off certain parameters for others that might have more impact on sound quality?
 
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amirm

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Here is another example of their measurements vs mine as far as -90 db 1 Khz tone. Remember that we are looking for sine waves here:

Schiit BiFrost Multibit DAC -90 db sine wave measurement vs SBF.png


Again we see general agreement. In each cycle of the sine wave there is a spike/glitch followed by something that kind of, sort of, looks like half of a sine wave. The instruments are different so actual details vary some but overall shape is the same. This DAC cannot reproduce -90 db sine wave (one bit less than 16 bit data) correctly.

It seems that they simply did not put any mitigation for glitching in R2R ladder DACs even though that is part and parcel of what they are.
 
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