Just a quick posting that the improved CAdence XSUB12 is now in stock. They are available on the Cadence website and will be up on ebay today at 6:00 PM PST.
Overview: New noise rejection circuitry, includes rerouting of preamp signal cables inside the amplifier and new improved shielded cabling for the preamp wiring. The last units were great, the complaints about noise on the last 500 sold were down to less than 10 units, but this should cure all the issues. We didn't think it was an issue on the last batch, but we choose to make improvement anyway.
Price is still $249 with free shipping. On the Cadence website you can try to apply coupon code save5. It did not work for me earlier today but should be running tomorrow.