The Short Version
The EverSolo C10 is a master clock. It is a box whose entire job is to keep time very accurately and tell your other components what time it is. Music does not go through it. It has no inputs or outputs for audio, only connections for sharing timing.
What exactly is a clock in audio?
Digital audio is a stream of numbers that has to be turned back into a wave at precisely the right moment. Every digital component has a small crystal oscillator inside it that ticks along and tells the circuitry when each of those moments is. That oscillator is the component’s clock.
The ticks are never perfectly even. The tiny variation between them is called jitter. Enough of it smears the timing of the reconstructed wave, and what you hear is a loss of focus rather than an obvious fault.
So what is a master clock for?
When you have two digital boxes connected together, each has its own oscillator and the two never agree perfectly. A master clock gives both of them the same reference to follow, generated by an oscillator better than either of their internal ones. One timekeeper instead of several.
What Is Inside the C10
The oscillator in the C10 is EverSolo’s second generation clock design, meaning it is a refinement of their earlier low noise clock work rather than a first attempt at it.
What is an OCXO?
It stands for oven controlled crystal oscillator. A quartz crystal changes its frequency slightly as it warms up or cools down, so an OCXO puts the crystal inside a small temperature controlled enclosure and holds it at a steady temperature. That is why the C10 needs about five minutes after switch on before it is at its best, and why the screen shows you the oscillator temperature while it settles.
What does SC cut mean?
It describes the angle at which the quartz crystal was sliced. The common cut is called AT. The SC cut is a more complicated, doubly rotated cut that costs more to make but reacts far less to temperature changes and to mechanical stress inside the crystal. It is the better starting point for a reference oscillator.
What is phase noise, and what do those negative numbers mean?
Phase noise is a measurement of how much the ticking wanders. The numbers are given in dBc/Hz at various offsets, and they are negative because they describe how far down the unwanted wander sits relative to the wanted signal. More negative is better. The C10 is specified at minus 115 dBc/Hz very close in at 1 Hz, falling to minus 145 at 1 kHz.
You do not need to interpret these to use the product. They are the way clock makers state quality, in the same way an amplifier states distortion.
Connections and Everyday Use
How many things can it connect to?
Four. There are four BNC sockets on the back, and each one is driven separately so that what you plug into one cannot interfere with the others. Two clock cables come in the box.
Does it only do 10 MHz?
No, although 10 MHz is the common standard. It can also put out 25 and 100 MHz, plus two families of frequencies that relate directly to music sample rates: 11.2896, 22.5792 and 45.1584 MHz for CD derived rates, and 12.288, 24.576 and 49.152 MHz for the other family. The practical benefit is that it works with more equipment.
What is the 1PPS socket?
One pulse per second. It accepts a timing signal from an outside reference, which is how very precise timekeeping is distributed in laboratories and from GPS based references. Most owners will never use it. Every C10 is calibrated for it at the factory regardless.
What does the screen do?
The C10 has an 8.8 inch touchscreen across the front. It shows warm up progress, the temperature the oscillator is holding, the current operating status and the 1PPS calibration, all updating live. It is genuinely useful rather than decorative, because it tells you when the unit is ready.
Where It Fits With Your Other EverSolo Gear
With a T10 and a DAC Z10
This is the pairing the C10 makes the most obvious sense with. The T10 is a streaming transport, meaning it collects the music and passes it along as digital without converting it. The DAC Z10 does the converting. Because that is two separate boxes, there are two separate clocks involved in one source, and the C10 puts them both on the same one. You use two of the four outputs and have two left over.
With a DMP-A8 Gen 2 and an AMP-F8
This combination works differently. The DMP-A8 Gen 2 already contains the streamer, the converter and the preamplifier in one chassis, and the AMP-F8 is a power amplifier, which is entirely analog and has no clock in it to speak of. So all the digital work is happening inside one box that already runs on a single internal clock.
That makes the C10 a weaker proposition in this system, and we would rather say so. It becomes worth considering if you add a separate converter such as the DAC-R8 next to the A8, or if you know you are moving toward a separates system and would rather buy the clock once.
With a DAC-R8
The DAC-R8 has an external clock input that accepts 10 or 25 MHz, so the C10 drops straight in. If you are running an R8 fed by a T8 or T10 transport, that is a two box digital chain and the clock has real work to do.
Is It Worth It?
Will I hear a difference?
Honestly, it depends. In a system with a separate transport and converter, both already of good quality, and speakers resolving enough to show small changes, people usually describe the effect as a firmer focus and a quieter background rather than a change in tone. In a one box system with no separate converter, it is much harder to justify.
Where should it come in an upgrade plan?
Late. A master clock is a refinement that sits on top of a system that is already working well. Speakers, room, amplification and the source itself all come first. If any of those is the limiting factor, a clock will not get you past it.
Do I need special cables?
Two clock cables are supplied, which covers the common case of clocking a transport and a converter. If you are driving three or four components you will need additional 50 ohm BNC cables.
Come and Hear It
This is a component best judged in the system it will live in. Come by the showroom in Timonium, or give us a call and we will talk honestly about whether your system is at the stage where a master clock earns its place.