[JDUBS]

Hey Guys

I'm not sure if this is the right circle for this....but there's no general digital circle.  Anyway, its somewhat applicable as I'm thinking about adding an external word clock to my 8-channel 24/192-capable DAC (TC Konnekt 48).

Anyone have any recommendations?  The Apogee Big Ben seems pretty popular in the pro audio world.  Or maybe the Empirical Audio Pace Car?

Thanks guys,
Jim

[ted_b]

Jim,
I may PM you about the TC Konnekt.  I am always no more than one weak moment away from getting a Metric Halo LIO-8 and wondered if you ever compared your multichannel DAC to any other, like the Metric, or Prism Orpheus, Lynx Aurora, etc. 

So, this is a fine Circle for this, as most external clock issues have to do with folks trying to get the best of hirez.  I will admit to a HUGE blind spot when it comes to clocking.  I am hugely interested in all things hirez, fairly knowledgeable about hirez music, download areas, ripping, burning and DACs...but clocking has me totally confused.       Master clocks, word clocks, slaves, etc.  I'd love to find a primer somewhere that dumbs it down.

I know several who like the Antelope Isochrone clock.

[JDUBS]

Thanks Ted.  The TC Konnekt is very good.  I'm feeding it via firewire from a Mac Mini using Pure Music.  The Konnekt outputs to three stereo amps for my tri-amplified system (soon to be quad-amplified once I add my subs).  I upgraded from a DEQX and haven't looked back.  This system is much more flexible and sounds better IMO.

Yep, the Antelope is another one that I've heard good things about.  There was just one on Audiogon for a good price that went quickly.  I love Steve's stuff, so I wouldn't mind trying the Pace Car either.

-Jim

[kyrill]

this is a fine clock too, aimed primarily to recording studio's "on a budget"
Sampling rates: six selectable rates, 44.1 kHz-192 kHz
I have that clock build in in their AD converter "sparrow", use it to digitize my LPs
clock around 1ps  accumulated jitter around 10ps, feed it LiPo4 A123 power


http://www.blacklionaudio.com/content.php?p=3

 http://www.youtube.com/watch?v=upfGSotdfZs
http://www.zenproaudio.com/converterandclockreviews.aspx

[DSD_Mastering]

Unless the DAC is seriously broken or the manufacturer did not know how to build a clock, then an external clock does nothing. Most of the time it makes it worse.

We've had everything from the Grimm to the Antelope Rubidium in here and they do nothing for a single converter system.

If you are using more than 1 converter to record, then a master clock makes the system more stable.

[firedog]

The Pace-Car isn't exactly a master word clock. There are 4 modes (copied from Empirical Website,but shortened a bit):

Mode 1: Synchronous word-clock
The source device must have a word-clock input, such as some high-end transports, some PCI cards such as the Lynx AES16 or the Transporter. A word-clock cable is connected between the Pace-Car USB and the source device. The customer provides two digital cables.

Mode 2: Synchronous master-clock
The source device must have a slave-clock input to use this mode. This can be added to Sonos, Squeezebox, Duet, Tascam US-144, EMU 0404 and other devices with a small modification by Cullen Circuits to add the Slave-Clock input. A master/slave-clock cable is connected between the Pace-Car USB and the source device.

Mode 3: Asynchronous
The Pace-Car USB is tuned to the source computer or device and tracks the rate of the incoming digital stream.

Mode 4: USB

But part of what makes the Pace Car work is that it is also a buffer. It does work (I use one in mode 2). The reply from Puget Sound above is probably correct, but he is thinking of a studio situation, in which the master word clock is used for synching different devices for editing. Generally the use in home audio is for playback. I asked Steve Nugent of Empirical a similar question about the Pace Car after reading an article (http://www.soundonsound.com/sos/jun10/articles/masterclocks.htm) which basically tested the use of master word clocks in a studio and said master word clocks in a studio situation can actually make the sound worse -much like what was said above. Here's what Steve replied, referring to that article:

Studio master clocks are not the same as how my products work.  They are generally used for synchronizing events for editing.  They are generally not used for playback.  His article confuses the word-clock with the frequency I call master clock, which is generally 128 or 256 times the word-clock.  Some of the things he says about master clocks are true, like with the A/D converter.  However, all of the "master-clocks" that he tests are actually word-clock generators.
 
The reason that I use the term "master-clock" is that this is the term that is used at the D/A chip.  Unfortunately, the word also describes a system word-clock in a studio environment.  Totally different.
 
The tests that he performs are interesting primarily for studios.  IMO, providing even a superb low-jitter word-clock is not very effective for reducing system jitter.  The clocks need to be low-jitter true master clocks at 256X the word-clock frequency.  This is how my devices work.  When you provide only word-clocks, then the device must synchronize its internal clock to this and then the jitter is a function of the internal high-frequency clock, not so much the external word-clock.

Didn't see the DAC  you're referring to in your post when I looked up the system in your profile, but if you just want a good quality feed/clock to your DAC from your PC, it seems the new Empirical Offramp 4 will do just as good a job as the Pace Car.