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Minidsp U-DIO8 USB to AES Converter Review

LD_

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#62
@amirm
@devteam

Hello and thank you for the measurements!

I own several miniDSP products, besides one EARS Headphone jig: a few DDRC-24 [which in its basic function would measure just OK like the reviewed:miniDSP 2x4HD] and one U-DIO8, that feeds a DDRC-88D+BM. FYI: Internal SRC should be avoided; at least on the 2x4HD/DDRC-24. Use high quality external SRC instead, to digital input the 2x4HD with 96kHz / DDRC-24 with 48kHz.

As amirm wrote in his 2x4HD review, the digital room correction makes a big difference - especially with Dirac Live - but as a "DSP company" I would expect more perfection from miniDSP on the hardware side, as well. The main issues I found in daily use however, which I also discussed with their customer support, are:

  • With the DDRC-88D an audible [loud] glitch appears through the loudspeakers when on input 1&2, whenever a change in sample rate happens (i. e., audio files with different sample rates playing one after another). As of their engineers, this is most likely related to how the current-old Firmware automatically matches sample rates. The workaround since more than a year now is either not to use input 1&2 - or to set up a fixed sample rate, instead. // Similar behavior I found with the DDRC-24, so I guess it is common amongst all their devices.
  • Speaking of Firmware, fixes happen rarely and the update process is not user-friendly, as well as the general use of their platform. Maybe they do have too many products to maintain by now and not enough qualified engineers to work on improvements? However, I find the documentation to be generally useful but in certain cases it needs to be updated with solutions found while searching their Forum. I can see the average user running into difficulties, preventing a smooth first start of the newly purchased DSP platform; it definitely is not "plug & play".
  • Unfortunately, it still is not possible to use different miniDSP devices with just one common software/driver installation on the same operating system. For instance, the DDRC-88D requires its own complete setup, as well as the DDRC-24. Of course, this partly comes down to licensing with Dirac Live but I believe a solution could be found to vastly improve usability; and to lower the risk of driver related issues originating in those very similar installations.

I was also hoping they would update their HDMI-featured units to HDMI version 2.0b, whereas a HDMI 2.1 video passthrough would probably make more sense in 2020. // A multichannel HDMI (and optical S/PDIF) -> AES/EBU converter with (at least) 4K/60Hz video passthrough would be a great device; but they seem not to see a market for it. An option to add on-board Dolby/DTS decoders would of course be great, on such an audio converter! And it would certainly be a welcome addition to the U-DIO8. Just imagine an audibly transparent [digital] multichannel Audio Switcher connected prior to the DDRC-88D, that would be fed by both the U-DIO8 and such a futuristic HDMI- (and optical S/PDIF-) based device... :eek:

====
The outputs of my DDRC-88D go directly into a Crown I-Tech 4x3500HD amplifier (for JBL M2), as well as into several JBL 708P and into a Tascam UH-7000 interface (for subwoofer). [The main reason why I did not opt for the JBL Intonato 24 was, that I do not require more than 8 channels.]

I am new to the topic of measuring audio gear on my own, but I do have an RME ADI-2 Pro FS interface and as far as I understand from the linked article, it is quite suitable for this purpose (with all its limitations, compared to amirm's APx555). Once I get to know how to reliably measure such complex gear with my setup and if there is any interest in it, I could try to provide measurements of the output(s) from the DDRC-88D; also being fed by an U-DIO8. I live in Europe, otherwise I would simply send the devices to amirm for check-up. ;)

Best regards

[EDIT]
Added information on SRC.
 
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BDWoody

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#63
What would the real world usecase be for a device like this?
I have it connected to my computer through USB, and use it to feed the ddrc88d, which is their 8 channel digital Dirac Box. Out from the ddrc88d in to the AES digital in on my JBL 708p's and 705p's. It has full bass management...and the ddrc's can be combined for more channels.

It could also just feed separate DAC's and skip the ddrc...

I'd be more interested in messing more with it if there were hdmi 2.1 or earc cards for PC's, but until I can feed it with hdmi it makes my utility a bit less than I'd like for a theater use.
 
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q3cpma

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#64
Does anyone know a simple class compliant USB to S/PDIF (or AES/EBU) interface that's at least stereo? These seem to be ridiculously expensive for something a lot less complex than a DAC.
 

LD_

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#65
I do have an inexpensive USB -> AES/EBU converter [stereo] but I am not sure whether it is class compliant. However, it does not require any driver installation on Windows; but it might not be in production anymore. I can provide you with some more information in about a week time, though.
 

BDWoody

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#66
Does anyone know a simple class compliant USB to S/PDIF (or AES/EBU) interface that's at least stereo? These seem to be ridiculously expensive for something a lot less complex than a DAC.
If you could use the extra channels, the minidsp udio8 can do this...
 

q3cpma

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#67
I do have an inexpensive USB -> AES/EBU converter [stereo] but I am not sure whether it is class compliant. However, it does not require any driver installation on Windows; but it might not be in production anymore. I can provide you with some more information in about a week time, though.
Thanks, I'm interested.
If you could use the extra channels, the minidsp udio8 can do this...
It's $325. How do you even justify that price for something that's mapping digital to digital?
 

BDWoody

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#68
Thanks, I'm interested.

It's $325. How do you even justify that price for something that's mapping digital to digital?
Edit: this is incorrect...it does not have analog in. It has USB input for up to 8 channels out via 4x aes, and it has 4xaes in for non USB input.

My mistake!

Well, it's also got 8x analog in...but I agree.. seems like there should be something cheaper...
 
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exaudio

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#69
Does anyone know a simple class compliant USB to S/PDIF (or AES/EBU) interface that's at least stereo? These seem to be ridiculously expensive for something a lot less complex than a DAC.
Topping D10. It's a DAC, but you can also use it as a USB to S/PDIF or TOSLINK interface. $89 US. I have 2 and they've been rock solid.
 

LD_

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#70
Thanks, I'm interested. [...]
So, the converter is a 'Hagerman HagUsb', modified to output 110-ohm XLR [= AES]. Unfortunately, it is discontinued but all information - for DIY - is still available via their website: Hagerman Audio Labs

HagUsb - USB to SPDIF Converter
Modifications done by manufacturer to output via XLR: "[...] So I found a slightly larger box that the same board fits into. Change a resistor value and output impedance is 110 ohms. [...]" For product image and further description, follow that link.

To test the class compliance, I connected it via "iPad Camera Connection Kit" to my old iPad (3. Generation; running iOS 9.3.5). The device is recognized as 'USB Audio DAC' but the following message appears: The connected device requires too much power.

I guess there are USB power supplies available, which would allow to overcome this message. However, that is not an issue when connected to a laptop or other devices with higher USB power output.
 
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dreite

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#71

Neddy

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#73
So I'm very interested in this.

Use case with OktoDAC:
For music, I'm running my OktoDAC Pro from a PC/ USB, no problem; but I still want a way to play back bluray movies (from my Oppo player's analog outputs).
- Less concerned about super hi quality performance for this use.
- (I'm doing speaker/room EQ downstream of the OktoDAC.)
- If I can use this to convert 8 channels analog to AES, then in theory I should be able to simply flip the OktoDAC from USB to AES inputs to switch between PC audio and Bluray discs.
- Volume control would be via the Oppo (presumably)

Questions:
@devteam
- Do you see any issues with feeding this unbalanced analog inputs instead of balanced? (Other than RCA-XLR adapters:)
- Would it require connections to a PC (USB host) for setup, or (more importantly) standalone use?
(I'm assuming I might need to connect it to a PC to configure it, but afterwards just leave it in standalone analog->AES conversion mode? Yes, No?)
- There's a reference above to a new version 'coming out' - can you clarify this at all?

@Okto Research
Can anyone see any likely issues with the jitter measurements and use with the OktoDAC?

All:
Any other concerns with this use I haven't thought of ?

Thanks!!
:)
 

Neddy

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#74
Well, it's also got 8x analog in...but I agree.. seems like there should be something cheaper...
So, it looks like I jumped the gun based on this comment.
Can anyone confirm that UDIO8 does support 8ch analog inputs?
There is no indication from their specs or user manual that it does.
<Sigh.>
 

da Choge

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#75
Can anyone confirm that UDIO8 does support 8ch analog inputs?
Neddy -- I think the UDIO8 AES outputs are digital; not analog. The 4 AES/EBU inputs on the OktoPro, as far as I know, are NOT analog; they carry two channels each of digital info (like a digital coax might, but not strictly and totally compatible, but I guess workable) -- it's more for pro audio setups. The USB input of the OktoDAC Pro can convert the digital stream into 8 channels of analog balanced output, but the 4 AES/EBU inputs are for different concerns (they each convert a 2-channel digital input signal to 2 channels each of analog output). The UDIO8 can be used with OktoDAC Pro, but perhaps not quite the way you want it to be. The Okto does have four AES/EBU digital 2-channel inputs compatible with the same UDIO8 four 2-channel digital outputs (and, depending on the cable you order, S/PDIF digital can be used also) -- but those are digital; not analog balanced inputs. I was kinda hoping someone with more expertise would answer your question before I did, but not the case so far. If I'm wrong I apologize. I looked into this unit some while back, and to do multi 8-channel audio in my setup that I was interested in, it would require some balanced to unbalanced conversion; and that conversion might degrade the signal. If you don't have 8-channels of balanced amplification, this might not be the best solution. Please - other more knowlegeable members correct me if I am wrong.
 
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da Choge

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#76
So, it looks like I jumped the gun based on this comment.
Can anyone confirm that UDIO8 does support 8ch analog inputs?
BTW, the UDIO8 may degrade your signal as far as noise somewhat - you can look this up on this same thread from the beginning -- not the greatest digital-to-digital converter as far as strict specs go; but still very affordable. Like Amir said, if it is what you need, it might be just fine.
 
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UliBru

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#77
So, it looks like I jumped the gun based on this comment.
Can anyone confirm that UDIO8 does support 8ch analog inputs?
There is no indication from their specs or user manual that it does.
<Sigh.>
The U-DIO8 has 8 digital input and 8 digital outputs. So there are no analog inputs.
To properly connect the U-DIO8 to the analog world you need to connect it to AD converter/s and DA converter/s.
By the USB connection you define the desired samplerate. There is a samplerate converter active for the digital inputs.
The 8 I/O channels are bundled in XLR connectors with two channels (stereo) each connector.
 

QMuse

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#78
The U-DIO8 has 8 digital input and 8 digital outputs. So there are no analog inputs.
To properly connect the U-DIO8 to the analog world you need to connect it to AD converter/s and DA converter/s.
By the USB connection you define the desired samplerate. There is a samplerate converter active for the digital inputs.
The 8 I/O channels are bundled in XLR connectors with two channels (stereo) each connector.
I believe U-DIO8 would also accept input from USB as it is USB Audio class 2.0 compliant device. Isn't that so?
 

UliBru

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#80
Usually the channel number of a soundcard is given by the channels connected to the outside world. The connection to the computer is not counted.
Of course you can feed the 8 output channels from USB without using the inputs. And you can read the 8 input channels by USB without using the outputs. The U-DIO8 does not allow to route the inputs directly to the outputs (other soundcards are capable to do this).
 
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