One deep concern I have about all capture cards is wether the sound is sampled from a crystal reference or not?

If this is so, there will always be potential for AV sync problems from domestic VCRs & analogue camcorders as the time base will be related to the mechanical stability of the tape transport. Surely it would be much better to truely lock the sound sampling to a harmonic of the 15625Hz line frequency so that any variance in speed will be compensated for.

Is this so?

PN