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As I have already told you via email, I have no means of measuring jitter directly on a devices's digital output. So no, I did not measure jitter in the SB3's digital output.
John Atkinson
Editor, Stereophile
JA-
I understand this, but using a reference DAC, you do have the ability to compare it to other transports/digital sources, as you did in your Apple AE review:
"However, this performance becomes moot when the AE's digital output is used. The grayed-out trace in fig.7 shows a similar spectral analysis of the Musical Fidelity X-DACV3's analog output while it was driven by the AirPort Express via the Monster TosLink cable. The noise floor has dropped by 4
The above method could also be used to indirectly measure jitter of several digital cables. It wouldn't be a direct measurement, but a measurement with respect to a 'reference' setup where the only changing variable would be the digital cable. Furthermore, it could help us see if in fact there is a correlation between measured jitter and what we perceived to be a better soundig digital cable. This sounds like a fun/instructive experiment to me.
Nice review on the Squeezebox. Now we need a f/u using a linear PSU, and obviously a thorough review of the Transporter once available!
Thanks. I will be doing a further examination on the SB3's jitter but as it performs quite well via its analog outputs in this respect, I don't think those using its S/PDIF output into an outboard DAC need to worry.
That's the plan.
John Atkinson
Editor, Stereophile
According to info posted on the SD forum:
Jitter measurement using Audio Precision equipment were:
SB3 digital coax out jitter: ~99ps
SB3 digital optical out jitter: ~892ps
To optimize S/PDIF output performance, the SB3 needs to be set for fixed digital output and then go into the web interface's player's settings, click on "Audio," set the Preamp Volume Control to 63.0, and then mute the analog outputs.
I will check it out. But without knowing what the measurement conditions were, it is difficult to draw meaningful conclusions from jitter measurements.
I will check this out, also. Thank you.
John Atkinson
Editor, Stereophile
Whether it "needs" this or not is a matter of rampant speculation right now. It is always interesting to me that when a tweak like this comes along, there are always exactly two camps. A) Those who think the tweak improves the sound or B) those who can't hear any change. Ask yourself this, why is it that nobody every reports the tweak makes it sound worse? If there is actually a difference, given the subjective nature of audiophile preferences, don't you think at least one person would find the "change" negative?
Wow, dude, like that's so profound.
I've always wondered about that as well.
There is much psychology at work in this hobby. The trick is to keep a level head and a full wallet.
One thing I didn't emphasize in my review, possibly because I forgot the SB3 has a variable output, is that I did all my auditioning, both from the analog outputs and the S/PDIF output, with the output level set to Fixed.
John Atkinson
Editor, Stereophile