Drawmer D-Clock

Digital audio facilities often require a number of clock sources, which are used to synchronise outboard processors to the system clock rate using external clock inputs. It uses a high stability TCXO (temperature compensated xtal oscillator) along with a microcontroller to measure the incoming sample rate to an accuracy of 2ppm and displays the information in three different formats, actual frequency (to one decimal place), nominal frequency +/- ppm error, or nominal frequency plus percentage of pull up or pull down. It has both AES/EBU and BNC word clock inputs featuring a zero latency loopthrough output with switchable high impedance to maintain the correct level of the digital signal for onward distribution. Sixteen BNC clock outputs are situated on the rear panel with a further four BNC clock outputs on the front panel for quick patching to other digital devices. The wordclock outputs can be fed from the wordclock input at any sample rate between 32KHz and 768KHz or derived from an AES11 input or stripped from an AES3 audio signal at any sample rate between 32KHz and 192KHz. Using an audio signal to provide the clock means even products without a wordclock output, such as some analogue to digital converters, or one of the many mic pre-amplifiers with internal A/D conversion but no word clock output, can be the master wordclock source for the whole digital studio.

• 2 in x 20 out Clock Measurement and Distribution Amplifier.

• 16 character blue LCD display providing a reference measurement of the incoming sample rate.

• Measures incoming sample frequencies up to 768 kHz to an accuracy of 2ppm or 2 microseconds.

• Display modes: ppm, ±ppm & % pull up/down for video users.

• Inputs: BNC with zero latency, 33 Ohms impedance.

• AES with with zero latency loopthrough.

• Outputs: BNC loopthrough / AES loopthrough.

• Universal voltage filtered mains power input.

INPUTS:

• BNC wordclock input: switchable 75ohm/hi z termination

• AES sync input: switchable 110ohm/hiz termination

• Sensitivity: 120mV

LOOPTHROUGH OUTPUTS:

• BNC Output: with zero latency loopthrough from input BNC

• AES Output: with zero latency loopthrough from AES input

MAIN OUTPUTS:

• BNC wordclock outputs 20 x simultaneous re-buffered BNC wordclock outputs with 33 ohm output impedance. 4 of which are on the front panel for ease of connectivity.

DISPLAY:

BLUE/WHITE LCD DISPLAY WTH THREE SWITCHABLE MODES OF OPERATION WITH MODE LED INDICATORS FOR EACH:

• Frequency: actual frequency up to >768KHz

• +/- ppm: nominal sample rate with +/- ppm error indication for 32,44.1,48,96 & 192KHz

• +/-%: Nominal sample rate with percent pull up/down indication for 32,44.1,48,96 & 192KHz

• Accuracy: 2ppm at all sample rates up to 768KHz, 0.1 Hz increments @ 48KHz sample rate

INDICATORS:

• AES/wordclock source select: led indicators

• AES/wordclock clock present: led indicators

GENERAL:

POWER SUPPLY:

Internal, Universal Input, 10 W

POWER REQUIREMENT:

< 6W

FUSE RATING:

T315mA for All voltages

conforming to: IEC127-2

FUSE TYPE:

20mm x 5mm, Class 3 Slow - Blow. 250 Volt working

DIMENSIONS:

• 1u, 19" Rack Mount

• Depth: 145 mm

• Weight: 1.7 kg