2. pc-audio
  3. 1215882518

Squeezing out extra perfomance: Reclockers

I am in the process of moving out of CD land and into a mac driven iTunes environment for all of my music (well, except for the vinyl:).

The setup I am using centers around a DEQX box. I like the DEQX because it just means less junk in the system - this thing has a VERY good DAC, preamp and the amazing active crossover/room correction ability. I figure it gets me about 90-95% of the way to what a dCS stack can do. Speakers are a homebrew that is pretty similar to the Emerald Physics CS-1 (no, not the 2. I am using 8 eminence drivers, but it was still inexpensive and pretty easy to build, and sounds INCREDIBLE with the DEQX). Files are going to be FLAC only, via xACT and Fluke, and Apple Lossless (at least until iTunes suppots FLAC natively, or somebody comes up with a better hack).

I have already decided I don't want to go the way of a Transporter, or a squeezebox, or a sonos. All are nice products, and have their thing going on, but I want to use a mac because I just dig the iTunes interface and at the end of the day, I want to control the head from my iPhone. Narrow minded, I know.

But Macs have a lot of jitter. They just are not precision audio devices. So the question is: how to reduce it?

It seems like in the reclocker market, there are the following options, priced from high to low:

Antelope Isochrone 10M - like $6k?
Esoteric...i forget the model, but its like 3K
Empirical Audio Pacecar - about $1200-1400 i think?
Apogee big ben - used around $1k

I'd be very interested in anyone's experience with any of the above reclockers/word clocks/masterclocks in the context of the Mac. Or, if you are aware of a product I should look at.

I really am open to suggestions, and, for sound quality, if I have to abandon the Mac as a front end I will, but it would be a bummer.
portypop
Post removed 
audioengr
3,282 posts
 
Portypop - I'll try a second time:

I2S is the bus most commonly used to drive modern D/A chips.

I2S is comprised of:

Master clock or MCLK - 256fs
Bit clock or SCLK - 64fs
Word Clock or sync - fs
Serial Data

Fs, or sample rate frequency is generally 44.1kHz for ripped CD files and 96kHz for master tapes.

In older DAC's, the Word Clock was used to clock the D/A conversion, but most modern DAC's use bit-clock. Master clock is generally used for digital filtering.

Word clock is the lowest frequency, so it is more easily used to synchronize the various digital devices in a recording studio.

For reducing jitter, reducing word-clock jitter is not that interesting. It may have a small improvement in some systems, but the bit-clock and master clocks are the ones that affect the D/A chip most.

Steve N.
Empirical Audio
portypop OP
6 posts
 
Steve -

Excellent and concise explanation - I thank you! Part of the difficulty of reading about this stuff is that it seems that many of the authors don't have such great command over the technology themselves, and terms have a regrettable tendency to be used interchangeably when they are actually not.

So really Jitter reduction is about bit clocks and master clock. Word clocks are incrementally beneficial in comparison.

Now I have some direction to try some things out!

Thank you all!
Ag insider logo xs@2x
drubin
3,274 posts
 
Keep us posted, Portypop. There are many among us in the same boat as you.
More to discover