Not sure if you have access to one or if it helps, but I used to use my Sony miniDV camera for doing very clean captures. It had audio/video inputs and would convert inside the camera to DV format and send it out via firewire. DV is not lossless, but very close and the files it captures are huge (25Mbps @720x480). The camera was a DCR-TRV30 which is old now, but I am sure there are others that do the same thing or maybe you can find one on ebay.
Hope it helps,
Mike