New Toy - Motu 8A

[March Audio]

I have a new toy The reason for it is to use as DAC and ADC for my speaker project. 3 way active with DSP crossover and room correction performed by Acourate. 8 output channels require, 3 per speaker + 2 subs. Given the processing requirement for the FIR filtering and the fact that I also need to input my home theatre into the mix I decided to give up on the idea of putting everything in the speaker itself. Hence the external audio interface and a cheap used 4 core i7 laptop from fleabay for Acourate and Roon core. Hypex Ncore NC400 amps will reside in the speaker, being fed balanced from the Motu.

http://motu.com/products/avb/8a

Now, I took a bit of a gamble as I had not heard the unit but I have been pleasantly surprised by its audio quality and technical performance. Particularly with the high level signals. Some measurements below with the unit looped back output to input (balanced) so its the ADC and DAC overall performance. I will perform some separate tests later.

Some interesting noise floor modulation though.....

ADC noise floor

Noise Floor loopback connected

-1dB

-10dB

-20dB

-60dB

-90dB

intermodulation

jitter

jitter zoom 1

Jitter zoom 2

All this makes me wonder if I should simply start avoiding consumer "hifi" products and stick to no bullshit professional..........

 

[March Audio]

Here are some plots of the MOTU ADC being fed by a Chord Mojo. Ignore the low level 50Hz mains harmonics, remember this is now a single ended input

Mojo to Moto -1dB

Mojo to Motu -60dB

 

[Sal1950]

Nice! Thanks for the very complete and detailed measurements.
Not having any background in Pro components it never fails to amaze me how much technology can be purchased for so little money. The comparison with audiophool bang for buck is enlightening.

 

[March Audio]

Indeed, as time goes on I become more and more disillusioned with the domestic audiophool arena. This unit is only about $800 and performs very well.

 

[March Audio]

Here are some gratuitous electro porn images for those that are into that sort of thing.

 

[March Audio]

Oh yes, the other new toy, Keysight u8903B

http://www.keysight.com/en/pdx-x202150-pn-U8903B/performance-audio-analyzer?cc=US&lc=eng

 

[tomelex]

whats the keysight cost, mate.

 

[DonH56]

MOTU has been around for a while but has upped their game the past few years. Might have to look into that, though my next purchase is more likely a cheaper universal player like the Sony X800 and a new 4k TV (next year, when QLED and such come down in price).

The Keysight lists for around $12k to $25k USD depending upon number of channels and options based on a quick check at myKeysight.

 

[RayDunzl]

Nice toys, Mr B...

 

[DonH56]

The 2nd and 3rd order IMD products look comparable, but in the test driven by the MOJO the 2HD term is clearly significantly larger. Wonder if that is due to HD in the Mojo or the single-ended input?

 

[Blumlein 88]

I have a new toy


snippage...........


All this makes me wonder if I should simply start avoiding consumer "hifi" products and stick to no bullshit professional..........

That bolded statement is more or less how I have been leaning lately. Should have been smart enough to figure it out sooner I feel. The MOTU performance would command some big money up into the few thousand range if it were a stereo DAC in a nice case with remote and proper BS to market it. Instead you have 8 ADC and 8 DAC and plenty of other functionality besides. AVB ethernet, Thunderbolt and USB 3. I have been looking at it for a multi-channel rig of my own. Just haven't been sure if I would be happy with the AVB use of it or not. You'll have to tell me more once you have it up and working to your satisfaction.

 

[March Audio]

The 2nd and 3rd order IMD products look comparable, but in the test driven by the MOJO the 2HD term is clearly significantly larger. Wonder if that is due to HD in the Mojo or the single-ended input?

When I get a moment I will hook up the Motu and the Mojo to the U8903B and compare results

 

[March Audio]

That bolded statement is more or less how I have been leaning lately. Should have been smart enough to figure it out sooner I feel. The MOTU performance would command some big money up into the few thousand range if it were a stereo DAC in a nice case with remote and proper BS to market it. Instead you have 8 ADC and 8 DAC and plenty of other functionality besides. AVB ethernet, Thunderbolt and USB 3. I have been looking at it for a multi-channel rig of my own. Just haven't been sure if I would be happy with the AVB use of it or not. You'll have to tell me more once you have it up and working to your satisfaction.

I'm not planning on using it in an AVB configuration so cant comment about that, but I am pleased with the audio quality. Compared to the Mojo, I would possibly say its not quite as good, but as I find with many DACs these days it is probably more a case of "different" than explicitly "worse". In the context of the use I will put it to, dsp crossover, those benefits will significantly out way the difference a dac will make.

I will post some links to a track recorded by the Motu replayed by itself and the Mojo (plus original) for your comparison.

 

[dallasjustice]

Motu is a great. It would be nice to know whether the AES67 ASIO works with Acourate for recording and playing logsweeps.

A few years ago I had a different pro DAC/ADC and it's AES67 didn't work with any of my DSP measurement tools.

 

[The Smokester]

...I find with many DACs these days it is probably more a case of "different" than explicitly "worse". In the context of the use I will put it to, dsp crossover, those benefits will significantly out way the difference a dac will make.

A naive question here: Your measurements of this DAC appear that this is more than adequate...Perhaps perfect within the limits of human hearing? Why would this unit sound any different from another similarly-characterized DAC?

I'm asking cause I'm replacing a great ($30k+) analog front end with digital... maybe I don't need to spend $20k on a Berkeley front end?

 

[Purité Audio]

Almost certainly not, unless you are looking for a status symbol rather than sound quality.
Keith

 

[The Smokester]

Almost certainly not, unless you are looking for a status symbol rather than sound quality.
Keith

I'm sorry but your reply is ambiguous to me. What is "certainly not"? Expecting the 8A to sound as good a $20k DAC or expecting the Berkeley to sound better than $800 8A?

Is it known what the parameters (minimum specifications) are for a DAC to be good enough to satisfy the most golden of ears?

 

[Frank Dernie]

I'm sorry but your reply is ambiguous to me. What is "certainly not"? Expecting the 8A to sound as good a $20k DAC or expecting the Berkeley to sound better than $800 8A?

Is it known what the parameters (minimum specifications) are for a DAC to be good enough to satisfy the most golden of ears?

PMFJI but I am sure Keith means don't expect the Berkley to sound better.

My last experience of DAC testing was a few years ago. I had a Linn Klimax DS, Resolution Audio Cantata, Weiss DAC2 and Metric Halo LIO-8 (an 8 channel pro ADC/DAC) at home. None actually cheap, but a 10:1 ratio of price.
With matched volume levels they all sounded the same. If pushed maybe I could hear a tiny amount more detail on the pedal noise of a piano with the Cantata, but I am not sure I could consistently pick it up blind. I thought the Weiss was a touch harsh but later didn't notice the harshness so whether it was imagined or dirty mains related at some time of day I don't know.
Certainly IME properly engineered DACs sound the same.
The Linn has a beautifully made case, but so does the Cantata (which I bought) at half the price.

 

[Blumlein 88]

A naive question here: Your measurements of this DAC appear that this is more than adequate...Perhaps perfect within the limits of human hearing? Why would this unit sound any different from another similarly-characterized DAC?

I'm asking cause I'm replacing a great ($30k+) analog front end with digital... maybe I don't need to spend $20k on a Berkeley front end?

Tell you what I would try before dropping $20K on a Berkeley, and I have a friend with a Berkeley they are excellent. I would try one of these pro pieces of gear. It is only a fraction of the price, and I am certain the difference is small if not non-existent.

One good choice might be the Antelope Zen Tour. It is priced at $1495 with superlative specs. It can be remote controlled via phones or tablets. Nice piece of gear. Antelope also makes some high end DACs and clocks targeted for home audio. They cost up around $5k and more. The interesting thing is they provide detailed specs on all their pro gear. Mostly these measure as near state of the art. Their consumer targeted DACs have no specs given. They just tell you how great they are. I suspect other than a fancier case, and most doing 384 khz instead of topping out at 192 khz you are getting the same performance in the pro gear. This is a portable recording/replay interface.

So I am sure it will be very good. Even if you later decide to go with the $20k solution, this lets you figure out just how you prefer to live with digital sources, can be used in a secondary or office or portable system. If you are keeping some analog front end this has excellent DA converters which could take the analog signal and still make use of it. Worst case, these keep a pretty good value, you sell 6 months or a year later getting likely 2/3's of your money back having learned something at a cost of about $500. In the context of $20k not that much and possibly saving yourself $19.5K in the process.

https://www.amazon.com/Antelope-Aud...=1496869367&sr=8-2&keywords=antelope+zen+tour

 

[RayDunzl]

Buying digital these days...

First figure out what kind of feature set you want.

DAC only?
DAC with analog (for use as a preamp)?
DAC with WiFi and Bluetooth and Ethernet and Hard Drives and Everything Else Under the Sun?

What do you need?

What do you think you need?