Other devices — SOtM sCLK-OCX10ultra

The sCLK-OCX10ultra is a 10 MHz master clock generator from SOtM of Cheonan, South Korea, introduced in October 2026 next to the sMS-500 network player and the sPS-550 power supply. It succeeds the sCLK-OCX10 and is meant to give every digital component in a system, from network players and digital sources to DACs, one shared timing reference. It sells for about USD 7,000, twice the USD 3,500 at which the sCLK-OCX10 went on sale in early 2018 with four outputs.

Key specs that matter

The clock produces a 10.000 MHz sine wave at an output level of 13 dBm, equal to 2.825 V peak to peak into 50 ohm, with a tolerance of 2 dBm either way. Ten independent BNC outputs sit on the back, each with its own isolation. Phase noise in the low-frequency region around 10 Hz is about 5 dB lower than on the sCLK-OCX10, for which SOtM quoted a typical minus 140 dBc/Hz at that offset. The unit runs on 12 V DC, accepts a deviation of minus 0.05 V to plus 0.5 V and draws up to 2 A. SOtM specifies an operating temperature of 10 to 30 degrees Celsius.

Engineering and use context

Most clock products send out a square-wave digital signal with sharp edges, whereas SOtM generates a pure analog sine wave through its own analog circuit design and an oscillator developed from the one in the earlier model. The isolation on each output is there to limit interference between the devices that share the clock when several are connected at once. With ten feeds available, a single generator can lock a complete digital chain, so even a complex setup does not need several master clocks. Every receiving component must have a 10 MHz reference input on a BNC socket. In the SOtM range, the sMS-1000SQ and sMS-200ultra players and the tX-USBultra have been offered with an optional 10 MHz master clock input for this purpose.

Pairing

SOtM presents the clock as part of a complete system with the sMS-500 network player, the sNH-10G network switch and its USB components, so that power, network, USB signal and timing are handled by matching parts. The sPS-550 supply has a 12 V setting with ample current reserve for the clock. Third-party DACs, streamers and transports can be locked to it as well when they carry a 10 MHz reference input.

Alternatives

The SOtM sCLK-OCX10 is the earlier master clock of the brand, a 10 MHz sine-wave generator with 50 ohm outputs as standard, a 75 ohm version on request and the same 12 V DC power requirement.