[ironmine]

Quote from here
http://6moons.com/audioreviews/aprilmusic5/u2_2.html:

"I suddenly remembered my earlier interview with April Music's Simon Lee: "I am listening to PC with normally ripped CD 44.1 to WAV played by Foobar upsampled to 24/96 over the Stello U2 into our DA100 Signature DAC to be upsampled to 192kHz. From there I go into the new Ai500 and MG20.1 speakers. This is fantastic! You can even compare it with dCS. You will see very soon. We are optimistic about PC or streaming media playback but we have to see what SONY/BMG, Warner etc will do for HQ music. For the time being, we will concentrate on standard CD playback (CD or ripped) at 24/96 played via 192kHz upsampling."

Holy Jesus! I can't believe it! The April Music designer upsamples the files to 24/96 in Foobar, then upsamples them further in Stello to 24/192! My ears would simply wither off at such "sound"... While I myself sometimes (less and less recently, especially after I added the subwoofer) prefer the upsampling (regardless where it's done - in Stello or in Foobar), but I can also clearly hear its drawbacks: the loss of transparency or the loss of bass (depth and impact and visceral feeling). What about the upsampling done twice?... He gotta be kidding...

 

[Wiza_Gab]

Eitherwise, the difference is always so small that I sometimes wonder if it's all Placebo.


On another note, I don't hear any difference between Optical and USB...

 

[ironmine]

Quote:

Originally Posted by Wiza_Gab /img/forum/go_quote.gif Eitherwise, the difference is always so small that I sometimes wonder if it's all Placebo. On another note, I don't hear any difference between Optical and USB...

It's not a placebo, the effect is obvious and only a deaf man would not hear it. The bypass mode makes my Rel Quake subwoofer work twice harder compared to the upsampling mode. Not only I can hear it with my ears, but also feel it with my whole body (the floor and the sofa underneath me shake more). So, I am confident that I can differentiate the bypass mode and the upsampled mode not only in a blind test, but also in a "deaf" test, i.e. with my ears plugged.

If it is a placebo to you, something wrong with your equipment.

 

[estreeter]

I dont know about the Stello, but if you read any of the stuff posts attributed to various Cambridge Audio boffins, they repeat the generally accepted claim is that jitter is higher from USB than from optical. I also consider the claim that a laptop running from batteries produces less jitter than one running from mains power to be 'common sense' to someone with my limited technical understanding. I particularly like the part where they concede that the DACMagic simply cant deal with very high jitter rates within the standard clock interval : I'm sure we are talking milliseconds, but anything I can do to give my DAC a headstart has to be a good thing.

 

[ironmine]

Quote:

Originally Posted by estreeter /img/forum/go_quote.gif they repeat the generally accepted claim is that jitter is higher from USB than from optical.

They say this, others say that... Where are the figures (measurement results)? Jitter can be measured accurately and expressed in absolute values. So, I want to see the figures compared, not rely on hearsay. We live in the age of science, it's 2009 now, not 1209... Come on guys...

 

[estreeter]

These are the only measurements I know of:

Stereophile: Cambridge Audio Azur DacMagic D/A converter

Although its USB input is really of only utility quality and shouldn't be used for serious listening, the Cambridge Azur DacMagic otherwise offers superb measured performance. In fact, considering its street price of $400, this level of performance is astonishing.

Those were the measurements taken by Stereophile, focussed on the overall abilities of the DACMagic, and these were supplied by CA. In true audiophile fashion, I am sure that they have been hotly disputed since the day they were published:

Stereophile: Cambridge Audio Azur DacMagic D/A converter

In short, people *have* taken measurements. Whether they support anyones stance on way or another is for the technicians to debate.

 

[ironmine]

Quote:

Originally Posted by estreeter /img/forum/go_quote.gif In short, people *have* taken measurements. Whether they support anyones stance on way or another is for the technicians to debate.

This is a very interesting read! That's what I meant and wanted to see. I wish the same data would be available for Stello DA100.

Maybe I will buy a USB/SPDIF converter, after all. When I get rich

If not as a cure against jitter, then at least as a way to bring 24/96 or even 24/92 signal from my computer to Stello. It would also be fun to compare different resamplers in Foobar.

 

[powerslave]

Quote:

Originally Posted by ironmine /img/forum/go_quote.gif Upstateguy, Could you please describe more specifically the sound difference between the USB input and other inputs (optical, coaxial) of Stello DA100? The reason I ask is because I need to understand if I need to invest into a USB-SPDIF converter...

I followed Upstateguy's advice and got myself a Blue Circle Audio Thingee as a USB-SPDIF converter passed into my DA100 sig via coax and the sound is more fluid and controlled. There is less background noise or hash. I don't hear as black a background via USB then i am getting now and you can hear better separation of instruments. The term black background is fitting for the thingee. Mostly though it's just the way the various sounds/instruments blend together so nicely.

 

[ironmine]

Quote:

Originally Posted by powerslave /img/forum/go_quote.gif I got myself a Blue Circle Audio Thingee as a USB-SPDIF converter

May I ask you how much you paid for it?

 

[powerslave]

Mines was used but the regular price is 169.00 + shipping for the base version which has usb in, spdif coax out on one end and analog out and headphone out on the other end. There are upgraded versions with more power or connections but the base was fine for my needs. There is a seller on audiogon who sells them:
AudiogoN ForSale: Blue Circle Audio USB
you should contact him for shipping info. Forget the looks, this thingee sounds sweet.

 

[ironmine]

Powerslave, can Blue Circle Audio USB pass 24/96 or 24/192?

 

[Andrew_WOT]

Quote:

Originally Posted by ironmine /img/forum/go_quote.gif Powerslave, can Blue Circle Audio USB pass 24/96 or 24/192?

No, it can't.
http://www.head-fi.org/forums/4511555-post69.html

 

[ironmine]

Does anybody know if DA100 can accept 24/192 signal and play it without internal downsampling? I am confused becaused the manual clearly says that the "digital input receiver: up to 96 kHz", but when I connected my iRiver H120 via optical to the DAC, I was able to feed it with 24/192 wav files and it played them...

 

[Andrew_WOT]

Quote:

Originally Posted by ironmine /img/forum/go_quote.gif Does anybody know if DA100 can accept 24/192 signal and play it without internal downsampling? I am confused becaused the manual clearly says that the "digital input receiver: up to 96 kHz", but when I connected my iRiver H120 via optical to the DAC, I was able to feed it with 24/192 wav files and it played them...

I doesn't take anything over 96khz, I tested it with hiFace. Toslink itself is limited to 96, meaning that in order to get 192 you need coaxial, but like I said even over coaxial it tops at 96. Manual is actually pretty clear on that. BTW, I retested usb input vs. Trends converter, clearly Trends -> Stello is superior, hiFace seems on par or better and offers up to 192 sampling rate.

 

[ironmine]

Quote:

Originally Posted by Andrew_WOT /img/forum/go_quote.gif I doesn't take anything over 96khz

Then, how come my Stello played music when I fed it with 24/192 files via optical from my iRiver H120 player? I am puzzled. How can it be explained?