TentLink Mode

This page describes the TentLink mode, which can be achieved by applying a combination of XO-3 and XO-DAC.

Canned modules

With an XO-DAC mounted inside an external DAC, the VCXO module mounted in XO-DAC is steered by the clock from the CD transport, controlled by the PLL within XO-DAC. This configuration is shown by the following figure:


The ultimate alternative is to swap the XO module and VCXO module (but leave both the XO-3 PCB and XO-DAC PCB and their connections in place). In addition, a simple interconnect (TENT-link) is required, feeding a signal back from the DAC to the CD player or drive. The configuration becomes like shown in the following figure:



The advantage is that we now have a free running oscillator (XO) at the DAC side, with a resulting jitter of typically 3ps rms (3-sigma). The actual conversion within the DAC, which is most important, is now carried out with the lowest jitter possible.

The CD player drive is synchronised by the PLL in XO-DAC. The signal in-between (TENTlink) is low bandwidth, and sufficiently filtered at both sides, so a simple 2-wire interface can be used. This signal pulls the VCXO inside the player and as such synchronises with the DAC. Please note that the actual frequencies used in CD player and DAC do not change. This may imply that you have to change XO and VCXO frequencies. For that reason a no charge exchange service exists, you only pay shipping charges.


XO-DAC contains a diagnostic output, to be connected to any audio amplifier / speaker set-up, or eventually a spectrum analyser. This output supplies you the demodulated, recovered clock from the input receiver.Demodulation is carried out, of course, with the clean VCXO clock.

The remaining signal is actually the low frequency content of the jitter spectrum around the clock frequency, it is simply mixed down to 0 hertz and as such you can effectively hear the jitter content.

What can I do with that output?

You can judge the quality of the front-end (CD player or drive, and interface), by connecting it to an audio amplifier, or spectrum analyser. It helps you improving your drive to an even higher level as it enables you to actually listen to the jitter generated in that drive.