As the “Lab-Nerd” at Alpha Audio, it’s always fun to be involved with clocks, jitter and its effects. We have a Wavecrest in the lab for a reason… don’t we? So when the Mutec REF10 Nano came on the market, we were very curious to see what the Germans put together. Spoiler Alert: they did their job ‘grundlich’!
We know the German company Mutec as a company that makes very decent products for very reasonable amounts of money. At Alpha, by now everyone has the famous Mutec MC3+ USB reclocker. A very nice and affordable reclocker with USB input.
Although the Mutec MC3+ looks a bit scary with all those LEDs, it is a ‘set and forget’ device. Just pop in the manual, set things right and play. Just don’t think about it anymore.
Mutec REF10 Nano
Now the Mutec MC3+ USB already sounds very good. But, as we know: it can do better. With an external reference clock that is… We have previously tested the REF10 and REF10-120. Both extremely good products that show a clear difference. In a positive sense. The question, of course, is: how does that pan out with the REF10-Nano?
Before we dive into that; first a small explenation what clocks do and what type of clocks there are.
There are many kinds of clocks in the world. Our own clocks at home and on our wrists, of course. Those usually have a “resolution” of 1 second. Or maybe a minute. The clocks in audio devices go a little further. There are so-called ‘word-clocks’ in studios that tick at 44100 Hz, or 48000 Hz. Or multiples thereof, depending on what is needed at the time. These are necessary to keep all devices in a studio running the same pace. Otherwise you get some serious problems.
Then there are models in CD players, streamers and, for example, dacs that run at 22.5792 MHz or 24.576 MHz. It can also be half that frequency by the way. These clocks are 256 or 512 times the word-clock (256 fs or 512 fs). So these frequencies are divisible by 44100 or 48000.
Finally, there is the 10 MHz clock. This is a reference clock. Now this is not a plural of any audio frequency. And thus a bit of an oddity. Usually this 10 MHz clock drives a synthesizer that makes 44100, 48000 or a plural of it. Weird … but that’s how it works.
Back to Mutec
So the REF10 Nano is a 10 MHz reference clock. On the back, it has four outputs: twice 50 Ohm and twice 75 Ohm. It is incredibly important that you use the correct output impedance as well as a correct BNC cable…. we cannot stress that enough. If you do not use the correct output and the right cable, reflections will occur and you might as well not use a reference clock at all. We switched between 50 and 75 Ohm and the difference is very audible. You lose focus and precision. By the way, the Mutec MC3+ has a 75 Ohm REF input.
On the front is one rotary / push button. With it you turn outputs on and off. Not much more to do….