They can. I have a reference player that is a modded Sony DVP-S7700 DVD player. There are several others that make superb transports as well, including Denon 2900, Pioneer DV-47A, Pioneer DV-09. All stock transports have weaknesses due to requirements for FCC emissions and sometimes due to poor design as well. See this white-paper for more info:
http://www.positive-feedback.com/Issue14/spdif.htm
Steve N.
Empirical Audio
manufacturer
http://www.positive-feedback.com/Issue14/spdif.htm
Steve N.
Empirical Audio
manufacturer