Open-source USB interface: Audio Widget

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rsdio

Member
Joined 2008
Onvinyl said:
I'm surprised. Subjectivly, it betters my RME ADI 2 by some margin!
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If you have access to test equipment, it's entirely possible that it betters the RME objectively as well.

I realize that RME has an excellent reputation, but I have seen their interfaces abused in ways that created more noise than less expensive MOTU interfaces. Well, not strict abuse, but marginal shielding resulted in 16 kHz noise on the RME that wasn't present in the MOTU. This was not the ADI 2 but the FireFace 400. I never did track down the reason for the 16 kHz noise, but it was present in the FFT and then disappeared when the MOTU 828 was swapped in to the identical 8-channel snake. Anyway, my point is not to disrespect RME with one example where perhaps the application was not ideal, but merely to point out that it's very possible that the performance is both subjectively and objectively better in certain conditions.
 
johnm

johnm

Member
Joined 2003
rsdio said:
Nice report, John. Thanks.
Click to expand...

Ta :)

After I posted that comment I had a good long listen. Thought the sound had improved, I was still aware of a curious kind of 'thinness' to the sound at times. Like all the sound were cut out of cardboard! (not the best description but hey haha!). Removed C15 (100uF Cerafine) and the sound properly fleshed out again, with the added 'wallop' given by C21/31, and the external PSU.

So - leave C15 unpopulated is my advice if using an external PSU plus 470uF for C21/31 :) Sounds very 'analogue-like' now, with the immediacy of (good) digital. Using 'BitPerfect' for the Mac and it's all gelling very nicely indeed.

- John
 
B

borges

Member
Joined 2003
Hi John,
could you perhaps go into some sort of schoolteacher mode and enter your mods with a red pen on the existing schematics?

Thanks for the modding work! I'm looking forward to uniting your and UnixMan's capacitor mods into an improved board.

Have you left the output caps open?

Børge
 
oneoclock

oneoclock

Member
Joined 2010
I built the 1Audio TL431 source and LED modification source.

Regarding VDD_XO, both TL431 and LED have produced improvements in Jitter respect to the original ADP151, but is slightly better in Jitter TL431 than LED source.

Now I try to see if there are any differences with LED source in the AVCC because have lower impedance than TL431 source?
 
1

1audio

Member
Joined 2004
Paid Member
Untangling noise and jitter is hard in these cases. A good supply will help both.
The width of the base of the 12 KHz is an indication of the random phase noise of the oscillator (and the capture system). Symmetrical peaks are the deterministic jitter components. The rest is noise.

Its all very good and the differences are small. Changes in the layout and where the connections to the board are made will be more significant I think.

They also use little space except the big cap.
 
U

udailey

Member
Joined 2008
picasaweb.google.com/udailey/MyRef#
Hi Folks
Here is a problem I am experiencing with the DAC I got from Borge yesterday. This is on first listen.
I use Windows 7 Home Premium and JRiver.
This noise I am experiencing has come up when I switch songs but infrequently. Also comes up in maybe 1 of 10 pause/play pushes. Later it started coming up by itself in the middle of a song. It lasts from 10-20 seconds.
Posted two videos. First is at beginning of song. Second happened in middle. I wasnt prepared to capture it the instant it began but about halfway through its noise.
Seems that it happens about every 10 or so minutes no matter if its middle or beginning of a song.
DAC does sound nice and price is great.
Crazy noise on DAC - YouTube
More noise but in middle of song - YouTube
 
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