Nothing wrong with having to wind the vol on the pre all the way up - it won't harm anything - but if it is still not enough a proper DAC with optical input in between TV and Pre would do it. The analogue outs on my TV don't work so I have to daisy-chain with a SCART into an old VCR and analogue out from that into the amp. Works fine. DVD is SCART from the TV then analogue 4.1 out to the 7 channel amp and powered sub.
Current Lash Up:
TEAC VRDS 701T > Sony TAE1000ESD > Krell KSA50S > JM Labs Focal Electra 926.