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Stello U3: async USB to coax & AES/EBU transport <Impressions updated> - Page 3

post #31 of 278
Quote:
Originally Posted by leeperry View Post

"performance varies" sounds a bit vague...what do you mean? Maybe your digital cable between the DAC and the U3 is catching interferences.



My guess as well. Won't be investigating into that.

 

Just gotten myself a DH Labs D110 AES/EBU cable. Will let it and the Stello U3 run in for 1 week to see if the sound ever change =)

post #32 of 278
Thread Starter 

so how's that AES/EBU connection doing then? tried to A/B against coax?

 

BTW, you may wanna roll more serious opamps for the I/V stage of your DAC: http://hifiduino.wordpress.com/2011/07/31/sabre32-vs-sabre32/

post #33 of 278
Quote:
Originally Posted by leeperry View Post

so how's that AES/EBU connection doing then? tried to A/B against coax?

 

BTW, you may wanna roll more serious opamps for the I/V stage of your DAC: http://hifiduino.wordpress.com/2011/07/31/sabre32-vs-sabre32/


I have just gotten 2 dual HD opamp from Bursons and had passed my DAC to the guy who carries it to see what other mods he could do for me. I will get back my DAC next week.

 

Never do any A/B against coaxial yet.


Edited by uelover - 8/11/11 at 7:45am
post #34 of 278
Thread Starter 

Those discrete opamps are notoriously power hungry and require at least ±18V to give their best, but I guess your reseller will ensure that this is all OK.

 

OTOH, the tube stage will color the sound to such extents that you might quickly reach the point of diminishing returns.

 

This said, looking forward to your impressions over AES/EBU regular_smile%20.gif

post #35 of 278

Yeah I was worried about that too which is why I passed my entire DAC to him instead of just buying the HD opamps and then plugging it in myself.

 

I will be relying on the Burson HD Opamp for the detail, speed and body while the tube for the roundedness.

 

Doing a comparison between the AES/EBU and Coaxial input will be easy because it is just with a flick of the switch =)

post #36 of 278

I have finally taken the effort to compare the sound between the AES/EBU and the Coaxial output of the Stello U3.

 

I hooked both cables from the Stello U3 directly into my Eastern Electric DAC. I could switch between the two inputs on-the-fly via the source selector on my DAC.

 

The cables used are the DH Labs D110 as well as the Monoprice coaxial rca cable.

 

Result: I really have a hard to picking up the difference between the coaxial and aes input. The coaxial is ever so slightly warmer and the AES/EBU is slightly more detailed. This is upon utmost scrutiny and constant repeating of the same portion of a single track. If I were to have any input switched at random, I will not be able to tell which input is being used.

 

Conclusion: I think that the coaxial output on the U3 is every bit as good as its AES/EBU output so potential buyers should not fret about not being able to fully maximize the U3 converter by tapping onto its AES/EBU feature.

 

 

I have had the Stello U3 for some time now and I can say that I really really like it. I don't find the Audio-GD DI with PSU any great performer but for this U3, I think it will be here with me for a long time =)

 

 

EDIT:

 

After owning the U3 for an extended period of time, I re-run the above comparison again. This time round, I have notice a large difference between the coaxial and the AES/EBU.

 

I am not sure if I should attribute that difference to (1) the different cable used for coaxial and AES, (2) the difference between the inputs on my DAC, or (3) the difference between the outputs on the U3.


Edited by uelover - 2/21/12 at 2:26am
post #37 of 278
Thread Starter 

I'm not too surprised because AES/EBU is essentially the same as S/PDIF...the only diff being that it's balanced and allows for longer cables. The major drawback of the latter is still very much there in the former: no discrete clocking signal.

post #38 of 278

 

Quote:
Originally Posted by leeperry View Post

I'm not too surprised because AES/EBU is essentially the same as S/PDIF...the only diff being that it's balanced and allows for longer cables. The major drawback of the latter is still very much there in the former: no discrete clocking signal.



Many people will nonetheless recommend AES/EBU over Coaxial given a choice. Even Alex, the maker of my DAC, as well as the local reseller for Stello U3, advised me to go AES/EBU input.

 

I think that upgrading the clock on the DAC may help more.

post #39 of 278
Thread Starter 

Originally Posted by uelover View Post

Many people will nonetheless recommend AES/EBU over Coaxial given a choice. Even Alex, the maker of my DAC, as well as the local reseller for Stello U3, advised me to go AES/EBU input.

 

I think that upgrading the clock on the DAC may help more.


Indeed, it might very well be that the AES/EBU receiving chips do a better job(clock recovery and all) than their S/PDIF counterparts, being a professional broadcast protocol and all.

post #40 of 278

A naive question(er) here:

 

With the U3, is it necessary to have a 'good' USB cable?

 

I assume a 'good' SPDIF cable would offer some sonic improvement, but am not sure about the USB going in.

 

Cheers!

 

Dave

post #41 of 278
Quote:
Originally Posted by Duckman View Post

A naive question(er) here:

 

With the U3, is it necessary to have a 'good' USB cable?

 

I assume a 'good' SPDIF cable would offer some sonic improvement, but am not sure about the USB going in.

 

Cheers!

 

Dave


Will let you know once I get the time to test it.

 

post #42 of 278

I found my unit has some noise. Every few seconds there is a very quiet click or pop. Tried swapping USB cables, SPDIF cables, USB outputs on the Mac, coax inputs on the DAC1... same noises every time. It's very subtle and very annoying.

 

I'm taking it back today for a replacement.

post #43 of 278

I am sorry to hear about that. Hope that your retailer will be able to get it replaced quick. I am using Mac too and everything works very well.

post #44 of 278

Just a word to say that this nice little piece of hardware (Stello U3) works perfectly under GNU/Linux. Here is how it is seen by alsa.

I plugged it into an usb port on a dedicated audiophile computer (without screen and keyboard/mouse) that runs the MPD server. That way, I'm sure the usb controller is not shared between various usb ports and devices.This configuration: only one usb port used, no graphical layer... may also minimize interruptions.

 

The MPD server addresses directly the hardware. Here is the alsa section of /etc/mpd.conf

 

audio_output {
        type            "alsa"
        name            "April Music Stello U3"
        auto_resample   "no"
        device          "cards.pcm.iec958"    # "hw:0,0"
        mixer_type      "disabled"
}
 

I'm really happy for I'm a chamber music live concert enthousiast, mainly string quartets, and could'nt imagine to get such life with recorded music.

post #45 of 278

That's quite a minimalist approach ;). Without screen and peripherals, how do you interact with the machine? From another linux machine on the same network, this one with a GUI and all?

 

Quote:
Originally Posted by schuetz View Post

Just a word to say that this nice little piece of hardware (Stello U3) works perfectly under GNU/Linux. Here is how it is seen by alsa.

I plugged it into an usb port on a dedicated audiophile computer (without screen and keyboard/mouse) that runs the MPD server. That way, I'm sure the usb controller is not shared between various usb ports and devices.This configuration: only one usb port used, no graphical layer... may also minimize interruptions.

 

The MPD server addresses directly the hardware. Here is the alsa section of /etc/mpd.conf

 

audio_output {
        type            "alsa"
        name            "April Music Stello U3"
        auto_resample   "no"
        device          "cards.pcm.iec958"    # "hw:0,0"
        mixer_type      "disabled"
}
 

I'm really happy for I'm a chamber music live concert enthousiast, mainly string quartets, and could'nt imagine to get such life with recorded music.



 

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