Just a quick shout out for Sam Palermo aka Skywave (business card attached, Teac/Tascam master tech). He took my decent sounding Tascam 122mkii cassette deck and turned it into a back-to-original-specs unit with new heads, professionally calibrated. This made what I heard originally sound much inferior. I (and, I am sure, many of you) are able to approximate the calibration of a typical deck, but a pro with the equipment and tapes to measure freq response, distortion, etc. and the experience to use them brings a whole new level of performance to bear. Very happy with the results (thanks to PBJ, who referred him to me).
This took a while to get done (like 10 months), and was not cheap - but I am a happy camper and planning to keep this deck as my reference.
OBG