bifrost MB technical measurements

The data presented were acquired as follows:
 
1.  PrismSound dScope III, picoscope 5243B
2.  DAC unbalanced output RCA
3.  100 Kohm load used for measurements
4.  44.1 KHz sample rate, 24 bit depth
5.  USB input – Audioquest Forest
6.  Toslink input - generic toslink optical cable
7.  Unbalance cable DH Labs Silver Sonic Air Matrix RCA
8.  Vaunix Lab Brick USB hub
 
Bifrost MB - AD5547CRUZ resistor multibit 16 bit resolution DAC
Measurements were performed over a period of 1 to 5 hrs of DAC power on time.
 
Notable highlights: 
Excellent channel matching, even in the distortion measurements
Jitter is close, though not quite as excellent, as Gungnir MB 
Short listening evaluation to note the multibit magic of dimension and depth present
Incedible performance for a 16 bit resolution DAC - this is one of my favorite DACs of all time for performance / price
 
USB input measurements:
 
Frequency Response

 
Frequency Response (y-axis zoom)

 
Dynamic Range

 
THD+N

 
IMD

 
Crosstalk

 
Inferred Jitter

 
Inferred Jitter (x axis zoom)

 
1kHz @ -70dBFS

 
1kHz @ -90dBFS (remember this is a 16 bit DAC - amazing fidelity and excellent channel matching at this level)

 
1 kHz gain linearity

 
Imaging

 
20 Hz square wave 0dBFS 6Vpp 10mS/div

 
20 Hz square wave 0dBFS 6Vpp 500uS/div

 
20 Hz square wave 0dBFS 6Vpp 100uS/div

 
Test setup:

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Thank you!  A couple of questions:
 
- What are the two humps in the jitter curve around 9 and 13kHz ?
- What's going on at 1kHz @ -90dBFS ?

boulos said:

  Thank you!  A couple of questions:
 
- What are the two humps in the jitter curve around 9 and 13kHz ?
- What's going on at 1kHz @ -90dBFS ?

Click to expand...

 
I do not know what causes the 2200 Hz sidebands from the carrier. However, they are at approximately -140 dB from the carrier amplitude and look symmetrical so I am not too concerned about them. Maybe @Jason Stoddard could provide some enlightenment.
 
From the graph title: 1kHz @ -90dBFS (remember this is a 16 bit DAC - amazing fidelity and excellent channel matching at this level)
-90 dBFS is barely a toggle of 1 or 2 bits for a 16 bit multibit DAC. So this is incredible performance for 16 bits. I have spent the last 7 days listening to this DAC through my various amplifiers with great satisfaction. I am a happy owner of all three Schiit multibit DACs, could spend my time with the Ygg exclusively. But I would be missing out on the auditory experiences the other two provide. These DACs really should be heard. All the flowery prose in the world falls short of the reality presented by these Schiit multibit DACs. I would rather have 16 really good bits with excellent channel matching, than the usual mediocre 17 to 18 from the claimed 24 and 32 bit Delta-Sigma DACs.

Thank you for the detailed response.  I am also already a happy owner of the Bifrost MB. 

boulos said:

  Thank you for the detailed response.  I am also already a happy owner of the Bifrost MB. 

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Played a Mobile Fidelity Sound Labs recording of Muddy Waters using the Bifrost MB, Project Sunrise III (12BH7 tube) and HD650. Listened to the album several times in a row. Couldn't stop listening. Wow!

atomicbob said:

 
 
I have spent the last 7 days listening to this DAC through my various amplifiers with great satisfaction. I am a happy owner of all three Schiit multibit DACs, could spend my time with the Ygg exclusively. But I would be missing out on the auditory experiences the other two provide. These DACs really should be heard. All the flowery prose in the world falls short of the reality presented by these Schiit multibit DACs. I would rather have 16 really good bits with excellent channel matching, than the usual mediocre 17 to 18 from the claimed 24 and 32 bit Delta-Sigma DACs.

Click to expand...

Did you ever the chance of comparing the Schiit MB DACs with the Audio GD counterparts, DAC-19 or Master 7? I hear they're on the same level, but slightly differently tuned: Schiit being more "bright", while Audio GD more "natural". Would be great to see some measurements for those two, too.

landroni said:

 
Did you ever the chance of comparing the Schiit MB DACs with the Audio GD counterparts, DAC-19 or Master 7? I hear they're on the same level, but slightly differently tuned: Schiit being more "bright", while Audio GD more "natural". Would be great to see some measurements for those two, too.

Click to expand...

I don't have the Audio GD counterparts available to me for measurement or listening at this time. Most of the DACs I measure and compare, I have purchased for use in my acoustic lab.

atomicbob said:

I don't have the Audio GD counterparts available to me for measurement or listening at this time. Most of the DACs I measure and compare, I have purchased for use in my acoustic lab.

Click to expand...

Having both Bmb and Gmb,does the single-ended of B sound better than the same of G?

There have been postings of such said,but we r unclear of the test conditions.

shutterbox said:

Having both Bmb and Gmb,does the single-ended of B sound better than the same of G?

There have been postings of such said,but we r unclear of the test conditions.

Click to expand...

Have a look at these posts:
http://www.head-fi.org/t/781268/the-diyrs-cookbook/60#post_12051821
and read for several more posts
 
Here is my concise, if somewhat irreverent opinion:
http://www.head-fi.org/t/785369/yggdrasil-gungnir-mb-bifrost-mb-a-terse-ribald-comparison#post_12012998
http://www.head-fi.org/t/785369/yggdrasil-gungnir-mb-bifrost-mb-a-terse-ribald-comparison#post_12015806

can you add stopband performance like this ?

If you measured a 4490 Bifrost and superimposed the charts on top of this, would it look any different?

I was comparing these measurements against the Stereophile ones for the UberFrost. 
 
Why are the -90db measurements so different between the Uber and the MB?  Or is it just a difference between how Stereophile measures vs how @atomicbob measures?

This is some great info, thanks @atomicbob !!
I'm extremely curious on what's the difference in jitter between the USB and SPDIF interfaces... Because I know the Bifrost MB has USB Gen5 which has a clock... so I'm wondering if the jitter is lower when using USB because of this. Right now I have a Modi 2 Uber and I'm using the SPIDF connectiong because it sonds a bit better to me, but I'm upgrading to a MB Bifrost in the near future and I'd really like to see some SPDIF measurements, or at least read some comments.