Nuverb card with TDM option, do I need extra hardware?

[Plymsol]

Hello

I am using a powermac 7100, with protools 3.1 free and a 441 interface, and it works and sounds great.
I send analouge into the 441, which then sends out digital AES to the Nuverb, The digital in recieves the AES out from the Nuverb and then goes analouge out of the 441. All in all 4 times A to D including the outputs from my Motu card.

My question is, I have a Nuverb TDM card from ebay. Can I just plug this into the Nuverb card and then operate the protools system in TDM mode or do I need a farm card? (presumably I also need also to find software authorisation disks etc..). This would then allow me to use Spdiff in on my 441 with the signal routed to the Nuverb internally via protools and would cut out any D to A as I could go straight out of the Motu via Spdiff. This would presumably sound better?

I have also read that one can make up a cable to go straight form spdiff to AES, but I really don't want to do anything that would Jepordise my Nuverb as it is sooooooo good.

Many thanks in advance

Plymsol