Douk Audio U2 Pro DDC - Poorman DDC for an affordable & clean digital signal

[monsterbill]

Can anyone recommend any other USB isolators to try between computer and U2 Pro DDC?

That's like half this thread right now, unless you're specifically referring to Texas Instruments-based isolators, in which case Altor is your best bet since it is externally powered.

For the ADUM-based options, I believe that's all the other ones listed in this thread, unless identified otherwise.

If you don't like the Aliexpress options, here's one from Amazon that works very well: https://www.amazon.com/gp/product/B00QU232UM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

To help you evaluate the options: USB 2.0 > 3.0, external power source > USB powered, Texas Instruments > ADUM

 

[sajunky]

If you don't like the Aliexpress options, here's one from Amazon that works very well: https://www.amazon.com/gp/product/B00QU232UM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Be careful. While in description it says 480Mbps, inside specs only states low and full speed. There is no mention of UAC 2.0 which require high speed.

Oh, just wanted to post it, but... See comment 08/17/2024. User got confirmation from a seller that it only support low and full speed.

 

[BrainFood]

I suppose hifimediy's is also pretty decent?

https://hifimediy.com/product/hifime-high-speed-usb-isolator-v2-usb-c/

Still have my U2 Pro (which sometimes comes in handy), although no longer being a poor man tend to use a Matrix audio X-SPDIF 2 without additional isolator these days -)

 

[monsterbill]

Be careful. While in description it says 480Mbps, inside specs only states low and full speed. There is no mention of UAC 2.0 which require high speed.

Oh, just wanted to post it, but... See comment 08/17/2024. User got confirmation from a seller that it only support low and full speed.

Okay, I had forgotten about this issue and I had to check my emails.

I bought it after having some bad experiences with Aliexpress. At the time, I had the same question as @sajunky and reached out to Cablemax. They didn't update some of the documentation when they changed the chip and upgraded to 480mps. They wouldn't, however, confirm they were using the ADUM4160 chip (as suggested by their new CM-M4160-ISO model number), and told me it was a business secret.

This does leave open an ambiguity, given the Amz commenter and the possibility of multiple versions. Since there are so many options it may make sense for others to go with another isolator that is more transparent.

I can attest that it works well with with chains going from isolator-->u2 pro-->Chord Hugo 2 (coax and optical), and isolator-->u2 pro-->most recent schiit multibt dac card. I tested files going up to 192kbps. I don't know whether this confirms that it is 480mps or not.

There were a few times I had drop outs with my Amanero-based DDC and had to reboot, but the Cablemax isolator was the only ADUM that worked at all with my Amanero. (I'm assuming the Cablemax is actually ADUM, but I think that's a safe bet.)

The Altor is significantly superior.

 

[sajunky]

They didn't update some of the documentation when they changed the chip and upgraded to 480mps. They wouldn't, however, confirm they were using the ADUM4160 chip (as suggested by their new CM-M4160-ISO model number), and told me it was a business secret.

Actually ADuM4160 chip is the obsolete one. A new series is ending with 5 or 6. It must be a coincidence.

This does leave open an ambiguity, given the Amz commenter and the possibility of multiple versions. Since there are so many options it may make sense for others to go with another isolator that is more transparent.

I can attest that it works well with with chains going from isolator-->u2 pro-->Chord Hugo 2 (coax and optical), and isolator-->u2 pro-->most recent schiit multibt dac card. I tested files going up to 192kbps. I don't know whether this confirms that it is 480mps or not.

It confirms, don't worry. The obsolete chip only works up to 96kHz. 192kHz require USB interface to work in 480Mbps (high-speed) mode.

If you can compare other isolators please report.

 

[Hummer25]

Running Audirvana on MacBook Pro out into U2Pro DDC via USB THEN coax out of U2 Pro into SMSL su1 but occasionally I get the odd glitch. Anyone any thoughts why?

 

[sajunky]

Running Audirvana on MacBook Pro out into U2Pro DDC via USB THEN coax out of U2 Pro into SMSL su1 but occasionally I get the odd glitch. Anyone any thoughts why?

Try power supply which came with U2Pro.
Also an inexpensive USB 2.0 hub (not 3.x), optionally with power supply.

It can be Audirvana problem. Do you run in Exclusive or Integer mode?

 

[Hummer25]

I use Integer mode. I run U2 Pro and DAC with separate LPS. I was wondering if a USB isolator between MacBook and U2 pro would help ?

 

[sajunky]

I use Integer mode. I run U2 Pro and DAC with separate LPS. I was wondering if a USB isolator between MacBook and U2 pro would help ?

Isolator will help if noise is a problem, but we don't know yet. USB 2.0 hub is good for testing, freely available. It became a neccessary tool, especially effective with MBPros. Now a new generation of isolators perform the same function, but it is a minimum $50 expense and you may prefer an expensive one, that's a problem. If your MBP has Type A USB port, always chose a device with this type of plug.

 

[Hummer25]

Isolator will help if noise is a problem, but we don't know yet. USB 2.0 hub is good for testing, freely available. It became a neccessary tool, especially effective with MBPros. Now a new generation of isolators perform the same function, but it is a minimum $50 expense and you may prefer an expensive one, that's a problem. If your MBP has Type A USB port, always chose a device with this type of plug.

My MacBook has USB C output high speed so may look at faster USB isolator like the JDS labs synapse?

 

[monsterbill]

JDS labs synapse

Isn't that just 480mbps like the other recommended ones? I don't think you need more than that for audio. IIRC, the JDS has that nice texas instruments chip, but no external power supply, which makes the Altor superior.

FWIW, with the isolators (as opposed to the DDC), I'm mostly focused on work vs. doesn't work, rather than incremental AQ differences. I did, however, hear a difference in my set ups going from USB powered isolators to external power, and a bigger difference going from ADUM chip to TI (aka, the Altor).

I'm currently running off a highspeed USB C output, but connecting to a USB A 2.0 cable via an adapter. I'm doing this to use an old but nice data cable, and also to avoid power going through the same line.

I'd be interested, though, to hear @sajunky 's thoughts!

 

[sajunky]

I'm currently running off a highspeed USB C output, but connecting to a USB A 2.0 cable. I'm doing this to use an old but nice data cable, and also to avoid power going through the same line.

You are doing right. Use USB 2.0 "High Speed certified" cable. I forgotten to mention it.
It was a requirement to mark a cable accordingly for a high speed operation. Do not use 3.x cable, there are extra wires inside. And of course if a device do not draw power, it is good to have a custom cable.

I'd be interested, though, to hear @sajunky 's thoughts

I expressed my opinion using these words in a quote below. Giving more elaborate explanation of Type C port many times before.

If your MBP has Type A USB port, always chose a device with this type of plug.

 

[Hummer25]

So I may not have to use a USB isolator after all as I have found replacing my cheap printer USB cable with a Audioquest cinnamon USB cable has sorted my problems with drop outs and glitches. Brilliant result. However the cable was not cheap!

Not sure where to go now with trying to improve my digital set up. DAC is phenomenal for the money (SMSL SU1). The U2 Pro plays nice with this DAC and both are independently powered with LPS.

 

[sajunky]

So I may not have to use a USB isolator after all as I have found replacing my cheap printer USB cable with a Audioquest cinnamon USB cable has sorted my problems with drop outs and glitches. Brilliant result. However the cable was not cheap!

Many printer cables are full speed only. But I wrote that you need High Speed certified cable, isn't? If it gave you a clue, I am happy.

 

[monsterbill]

Not sure where to go now with trying to improve my digital set up.

Glad you got it working, but since you are looking to improve your digital set up, on this thread the obvious answer is still get a cheap isolator. IME the U2 Pro benefitted a lot from it.