Hi Steve
Once you were a kind of DEQX expert..
I hope you may answer my questions as I think a digital expert is needed and maybe you can point me to advises.
I posted these question first in the LAB section but I presume tio have here more "digital knowledge"
If it is inappropriate for this forum I expect you to feel free to remove this post.
I find the deqx PDC-2.6 though to have some minor min points after their HD upgrade. Their internal analogue side can still be fully updated with better film output caps (Teflon for instance)
and
I am already years searching for a better clock. in order to remove jitter. I updated the clock finally last year in the USA with a precision clock and dedicated own pws. It made the sound analogue to me and some more.
Then 7 months later the unit did not finish its start up sequence. A DEQX technician almost got angry at me and blamed the new clock for the problems. He removed the superclock and got the original clock back, a clock based on ideas about clocks 8 years ago ( that is how "old" my DEQX is) . I still consider it very strange to blame the new clock, as the unit worked flawlessly for almost 8 months, 5 days a week, 2-5 hrs a day.
So my question is, is it possible if you see on the board a canned crystal clock, to only replace it with a better clock ( same oscillation freq. of course) without affecting the rest of the schematics as if the system still "thinks" it is the original clock only more precise? This at least is suggested by all those "replacement clock manufacturers. But what about Z-in and Z-out of the clock compared to the replacement "module"? Does that play a role?
However I cannot leave the analogue musicality of the DEQX behind by accepting DEQX standard clock solution. ( which was acceptable good but not to the standards of for instance
http://www.newclassd.com/index.php?page=36 with their super clock and ditto pws
So I though maybe a whole different solution is DEQX digital out board, which bypasses the PDC 3 internal dacs and analogue volume control to be replaced by 3 external dacs.
This digital out board has an AES "IN" for an external word clock. I assumed faulty that this outer clock would switch off the on board clock and take over. According to this technician this external link is only used to "reclock" the output to the ext. freq. So if DEQX processes a 16 bit 44.1khz red book file, and the ext clock is set to 96 khz, the output of the DEQX will be this 96 khz 24 bit. At least this is how I interpret the technician's message:
"Kyrill,
The sync input [of the digital board] has nothing to do with the PDC clocking!!! The sync is only to control the sample-rate convertors of the Digital output so you can set the sample-rate I.e. 44.1, 48, 88.2 or 96k "
I always thought when an ADC or DAC accepts an external word clock, it also accepts the precision or lack of it of that particular ext. clock. Is that right? To what extent means "..to control the sample-rate converters"?
Is the DEQX only reading which freq (44.1-96khz) but it resamples it on the the board independent of the quality of the ext. clock? the technician 's email reads that way.. If so, the jitter quality of the external word clock has no influence whatsoever on the jitter output of DEQX re-samplers?
I hoped that if the last stage prior to DEQX's output was fully controlled by an ext clock, then by choosing a high quality clock to have less jitter at DEQX's output and so can leave the internal PDC clock alone.
All questions related on how to precise the clock freq for DEQX in order to lower the accumulated jitter.
Any ideas?
(3 Pace clockers for the DEQX 3 digital outputs (bass/mid/highs) would solve my problems, but beyond my budget)