[Puma Cat]

Additional engineering information from Uptone:

A note about our inclusion of an SFP cage:

Use of optical into—or out of—EtherREGEN is not required to obtain best performance. The whole point of all the isolation and re-clocking techniques we are using (in dual domains) is to make most all of the upstream stuff not matter. Other than the complete galvanic isolation that optical offers going into the EtherREGEN (which we duplicate going across the moat), there is no advantage to running optical into it.

If you happen to have a router with an optical port and have already run many feet of optical cable to your music system rack, then sure, use the optical port of the EtherREGEN. But don't go out of your way to run optical if you do not already have it. And of course for the few people who have an endpoint with optical input (the excellent Sonore opticalRendu comes to mind), one can “turn around” the EtherREGEN and feed that DAC-connected endpoint from the optical cage.

Only Gigabit LC interface modules are compatible with the SFP cage of the EtherREGEN. They can be SX Multimode or LX Singlemode, as long as they match what is used at the other end of the optical cable.

Extreme usage with an External Reference Clock:

The Crystek CCHD-575 XO used in the EtherREGEN is about the lowest phase-noise production XO available. [Sorry, but the $50~$100 OCXOs we see tossed into stock switches do not outperform the Crystek at low-offsets where it counts; Manufacturers have to spend $500 and up to obtain OCXO clocks with significantly lower phase-noise than the Crystek we use.]

Yet some audiophiles have discovered benefits using expensive ultra-low-jitter/low-phase-noise 10MHz reference clocks with their DACs or USB streamers and conditioners. A clock synthesizer (to generate the various frequencies) is always required for a device to accept an external reference clock. Since we already utilize a very advanced one to produce the 4 clock lines in the EtherREGEN, it was easy for us to include provision for connection of an external 10MHz clock. The BNC jack and termination resistor of the EtherREGEN are for a 75ohm clock line.