Mark Z. said:

Mark D. Zacharias May 3, 5:34 am show options

Newsgroups: rec.audio.tech
From: "Mark D. Zacharias" - Find messages by this
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Date: Tue, 03 May 2005 09:34:19 GMT
Local: Tues,May 3 2005 5:34 am
Subject: External DAC to receiver question
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Arny Krueger wrote:
Mark D. Zacharias wrote:
still learning wrote:
David B asks:

I am auditioning a used California Audio Labs DAC with my home
theatre receiver (Kenwood 6060). I'm hoping to use this more for
two channel in
the future.
The light on the receiver that signals clipping will come on
briefly
(flicker) during playback on some CD's. There is no audible
clipping but when I play these same CD's using the DAC's in the
receiver or the DVD/CD player (Toshiba), I don't get the flickering

clip light. It is my guess that even though there is no audible
clipping going on, this is not a good thing. Any imput from you
learned gentlemen would be
appreciated.

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Conventional wisdom is that outboard DAC's in general are a bad
idea
since they can't improve on the perfromance of the one inside your
CD player or DVD player. What they likely CAN do is degrade
performance.


My advice is return it and learn more about why they aren't a good
investment.


Where do you get that?


Practical experience. Theoretical analysis.


An external DAC may or may not improve on a
built-in DAC circuit, but there is no such "conventional wisdom".


That would depend on which circles of expertise you investigate.


Many built-in DAC's are cheap, cheap, cheap.


Despite their low prices, they are often up to the task at hand. Here

are the measured performance specs for the DAC in a $39 DVD player -
a
Apex AD 1201:


Frequency response (from 40 Hz to 15 kHz), dB: +0.07, -0.05
Noise level, dB (A): -95.2
Dynamic range, dB (A): 95.0
THD, %: 0.0012
IMD, %: 0.002
Stereo crosstalk, dB:-92.9


A digital output going
to a competently designed DAC will probably sound noticeably better
than many all-in-one units.


Once performance achives levels that can now be achieved quite
inexpensively, there is no possible audible advantage to further
improvements, in the context of the true meaning of high fidelity.



I appreciate that Arny, but my main point was that these is still a
chance
that a quality piece will sound better than a piece of crap, and the
guys I
was at odds with discounted this possibility 100%.

At no time did I see any mention by the OP that his CD player was a
piece of junk. I stand by my original statement, that outboard DAC's
are unlikely to improve the performance of a CD player. This does noit
mean that there couldn't be some that might be helped, but only that
the odds are long.

The JUNK that I deal with on a daily basis cannot be expected to hold
up to
the highest standards in EVERY case.

I never said anything about every case, I can't speak for anyone else.

That's simply not even logical to
expect. Never mind the "state of the art" in semiconductor design for
the
moment. Do you believe that EVERY no-name manufacturer in China ALWAYS

designs their chips etc to the highest, or even to ordinary standards?

I sadly often encounter counterfeit semis instead of the original
parts I'm
looking for. What if some of the chips in these pieces of junk are
counterfeits (which by the way some almost certainly are) ? Will they
stand
up to the "they all sound the same" test?


Possibly not, but it is likely that the vast majority of DAC's are
sufficient to the task.