External Word Clock Set Up Demo Recording Quality Comparison

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• published: 28 Oct 2016
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"Requiem for the Living" by Dan Forrest appears courtesy of Fred Bock Music Companies. Find out more about Dan & FBCM at: http://danforrest.com/music-catalog/requiem-for-the-living/ http://fredbock.com/ 2:00 - OVERVIEW, Black Lion Audio Micro Clock XB 5:24 - CONNECTING DEVICES & CLOCK 10:03 - UA 4-710d Sample Rate Lock (close-up) 10:25 - Setting up the Zen Studio Control Software to accept WC 13:22 - SAMPLE #1, clock OFF 14:24 - SAMPLE #2, clock ON 17:18 - Lansky's opinion (for what it's worth.....) The title says it all! Lansky explains the nature of time & why some humans care while others do not as well as how to set up an external word clock generator with an interface & outboard preamp/A/D converter. Devices demonstrated include the Antelope Audio Zen Studio interface & Universal Audio 4-710d preamp. The featured word clock generator is the Black Lion Audio Micro Clock Mk III XB: https://blacklionaudio.com/product/micro-clock-mkiii-xb/ Listen to the Choral Arts Ensemble of Portland: http://www.portlandschoir.org/ http://www.LanskySound.com http://www.Facebook.com/LanskySound Here is some email correspondence with the clock's designer, Jesus: On Mon, Oct 17, 2016 at 11:14 AM, A. Lansky adam.lansky@hotmail.com wrote: Howdy Sid, Thanks for the quick/detailed answers. I'm trying to wrap my head around how a clock's technical specs relate to perceived quality to better understand the differences I am hearing. For example, the Antelope Zen Studio's clock has the following specs: Clocking Stability less than +/-0.02 ppm, oven controlled at 64.5 C/ 148.1 F Clock Aging less than 1 ppm per year Clock Calibration less than +/-0.001 ppm Compared with the XB's 25ppm, strictly as a matter of what's "on paper", Antelope's clock has tighter tolerances. I know the BLA team is well aware of this data having worked extensively with the Zen. Are you able to explain how a clock with a lower resolution is able to outperform what is a statistically superior device? This is not to pass judgement as to which device I think sounds better, just want to understand the science of things as I continue my testing. Thanks! -- A. LAИSKY From: Black Lion Audio Sent: Monday, October 17, 2016 12:01 PM To: A. Lansky Subject: Re: Invoice from Black Lion Audio Hey Adam, while I could handle the other questions, I had to refer to our clock's designer to answer this one for you... my brain's just way too small! In response to your last question, this is what he stated: "While he's right that the specs on paper are better, understanding those specs is important. The .02ppm basically explains how close the clock is to the stated frequency. That's more of a long term reading. That's the basis of many companies' claim that you'll only be off by so many millihertz every so many weeks. While that's definitely an important stat, there's a few things to keep in mind: For one, if your whole system is running off the same clock, then the importance of that spec is somewhat diminished because they are all still synced together. The variations in the master are reflected across all the units. Another thing to bear in mind is that many of the stats are long term averages that show how a clock performs in a system. At .02ppm we're referring to a minor fraction of a fraction of a percent as compared to a mere minor fraction of a percent. One of the important things that we try to emphasize in our clocking systems is more the short term performance. We need to remember that when converters are involved, short term jitter becomes very important. Phase noise is the random variations in clock pulses that are often times disregarded because they technically have no affect on the overall long term timing. They won't affect that ppm spec on the datasheet. The issue is that with converters, every clock pulse counts. That pulse acts as a map that tells an ADC system when to take a sample and a DAC system where to place the sample during reproduction. When the ADC system has a different map than the DAC system then that sample will be placed in the wrong spot (even if by a slight amount) which then manifests itself as distortion in the audio band. That is to say, if the ADC recording sample is taken when the clock is say, 200 picoseconds off but the DAC's playback of that same sample is only 20 picoseconds off, then that sample may be placed in the wrong spot during playback. Many folks say it's inaudible, but we don't agree. We feel that this emphasis is why our clock has such an effect on the audio quality. While clock accuracy is important to us, we've always been people to look beyond the spec sheet, instead of just seeing what everyone else posts and then trying to beat it. I hope this makes sense." Like he said, I hope this makes sense, Adam! -- Sid