T1 10MHz Time Reference

  1. General
  2. Features
  3. Options
  4. Specifications

Timing in digital systems is the key to carry and to faithfully convert digital audio content. Why so? Let’s imagine that a digital to analog converter chip is fed from a clock containing a high level of phase noise, otherwise known as jitter in the time domain. Instead of being evenly spaced in time, the digital audio information converted to the analog domain is spread randomly around the ideal time, introducing undesired artifacts. The better the clock source, the lesser the phase noise, the more precise the conversion.

An ultra-low phase noise, high accuracy 10MHz oven controlled oscillator (OCXO) forms the heart of the T1, CH Precision’s first clock generator.


• 10MHz nominal frequency
• Square wave: 500mV or 1V peak to peak, selectable for each output
• Sine wave: 500mV or 1V peak to peak, selectable for each output
• 6 outputs, 75Ω BNC coaxial
• Transformer-coupled outputs
• Independant control of wave form for each output


• GPS input to suit the CH Precision GPS option
• TTL input for external synchronization
• Ethernet for remote control (CH Control App)
• USB for firmware upgrade

Power Supply

• Dedicated ultra low noise, three-stages discrete regulated linear power supplies for each section
• Galvanically isolated power supplies for the OCXO, the OCXO buffer and the output buffers
• Magnetically and electrostatically shielded toroidal mains transformer


• OCXO fitted inside a heavy aluminum block for improved core temperature stability
• OCXO aluminum block mounted on soft silicon gel for maximum damping
• Power transformer mounted on silent blocks

To avoid the inexorable drift in time of oscillators, a GPS option is available. Locking on satellites’ ultra-stable caesium clocks, it ensures that the T1 will perform identically today and for many years to come.

Nominal frequency 10MHz, +/- 20ppb typical in internal mode, factory adjusted
10MHz, +/- 1ppb maximum with GPS option locked for 1 hour
Tuning range +/- 0.1ppm via BNC input
Phase noise performances better than -105dBc/Hz @ 1Hz deviation
better than -125dBc/Hz @ 10Hz deviation
better than -145dBc/Hz @ 100Hz deviation
better than -155dBc/Hz @ 1kHz deviation
better than -165dBc/Hz @ 10kHz deviation and above
10MHz Outputs
Output level 500mV or 1V, peak to peak, loaded with 75Ω termination, adjustable for each output
Waveform type Sine or Square wave, adjustable for each output
Output impedance 75Ω, 6x BNC coaxial connectors
External BNC Input
Input level 5V TTL level
Input impedance 47kΩ, BNC coaxial connector
Accepted signal frequencies

44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, 192kHz

Reference signal frequency deviation maximum +/- 0.1ppm around the above signal frequencies
Display 480x272 pixels, 24bits color, AMOLED
Mains operation Selectable 100V, 115, 230V AC, 47-63Hz
Fuses value and location Standby fuse (black holder): 250mA T (230V AC), 500mA T (100V AC, 115V AC)
Main fuse (white holder): 1.6A T (230V AC), 3.15A T (100V AC, 115V AC)
Power supply consumption <1W (standby), 60W max in operation
Dimensions/Weight 440 x 440 x 133mm (W x D x H), 26kg
Remote control

Ethernet based system control via the Android CH Control App

Adobe-PDF-Document-icon Product flyer (preliminary)
Adobe-PDF-Document-icon User manual
Compressed-File-Zip-icon T1 firmware version 1.4 (release date 2017-10-31)

CH Control application 2.2.1 (release date 2018-01-03)