Mutec manufacture high‑performance master clocks, and digital-format and sample‑rate converters. Everything is well designed, well engineered, and surprisingly cost effective. The MC3+ Smart Clock is a new‑generation product, which combines versatile master‑clock functionality (based on proprietary 1GHz internal clock technology) with a sophisticated and unusual audio re‑clocking function, which is designed to reduce jitter dramatically from a digital source. An external reference clock (including 10MHz atomic or GPS clocks) can also be redistributed through the MC3+, and the outputs are maintained in a fail‑safe way if the reference is lost.
The MC3+ is a 1U high, half‑rack unit with an internal universal power supply (90‑260 V AC, 10W). A mains on‑off switch is integrated with the IEC socket. External reference clocks are accepted via BNC connectors (wordclock, x256 Superclock, or 10MHz atomic/GPS), S/PDIF (coax and optical), or AES3/AES11. Five sets of clock outputs are arranged as three pairs of wordclock BNCs, S/PDIF (coax and optical), and AES3/AES11.
Banks of LEDs indicate the current settings, starting with operating mode (internal clock, external clock, or re‑clock). The next LED groups indicate the selected external reference source, the current output sample rate, and the rate multipliers applied to each output group. The maximum output rate is restricted to 192kHz, plus x256 Superclock for the BNC outputs.
More LEDs on the right‑hand side indicate the current status (reference lock, fail‑safe output-rate hold, and digital audio present), and finally the master‑clock's working sample rate. Three oval LEDs on the left-hand side actually comprise a power‑on LED and two push‑buttons. The latter cycle through the set‑up options and select the required modes impressively: configuring the unit becomes entirely obvious within 10 seconds of pressing the buttons! Essentially, each press of the Menu button selects the next bank of LED indicators, whereupon the current selection flashes. Pressing the Select button then cycles through the various options, and the selected mode becomes active a few seconds after the last button press.
The internal and external clock modes are entirely conventional, albeit with excellent performancethanks to Mutec's bespoke 1G ultra‑low jitter technology. The Re‑clock mode allows an external digital audio signal to be phase‑aligned with an external reference clock (but not sample-rate converted), while simultaneously reducing source jitter dramatically. This can improve the audio quality substantially if employed between a jittery source and a D‑A converter susceptible to input jitter. Apparently many customers have bought the MC3+ for this purpose alone and report excellent results.
The MC3+ Smart Clock is a very smart clock indeed, with unusually flexible configurability, excellent technical performance, an attractive price, and a brilliantly simple user interface. Highly recommended. Hugh Robjohns
£559 including VAT.