[cmjones01]

Yes, the Denon is a dual capstan machine, and usually does a good job with difficult tapes (for example, cheapo pre-recorded computer games where the pressure pad/sponge has rotted away). I've tested the machine in various ways. I don't have a head height gauge (yet) so I set the head height using tones recorded on left and right channels by my Technics RS-B355 which, though it's a budget deck, I've owned from new and am 100% certain it hasn't been fiddled with or repaired or adjusted. It's also the deck on which the vast majority of my cassettes were recorded. It was quite straightforward to find the point at which both channels replayed left and right at the same levels and at maximum amplitude, indicating (to me at least!) that the head was lined up with the tracks on the tape correctly.

With some confidence that the tape path was now sane and unlikely to damage any cassettes put in to it, I used my test tape from ANT audio to set the replay levels and check the speed. Remarkably, the 400Hz test tone on the ANT tape measured correctly to within 0.5Hz without any adjustment, which is impressively accurate. All this done, the deck replays cassettes recorded on the Technics perfectly, even those recorded with Dolby C. Once replay was right, setting up recording was OK once I'd figured out the faulty presets.

I suppose there remains the possibility that the "difficult" cassette was recorded on a misaligned machine, but I know exactly which two decks I was using on the date it was recorded. One of them I no longer own, a Technics RS-M45, but that has fixed head height so was unlikely to be much wrong. The other is an Akai UC-M2 which I do still have in storage (its friends the UC-K2 tuner and UC-U2 amplifier are in use as our kitchen radio!) so now I feel I should dig it out, give it the new belts it definitely needs, and test it to better understand what's going on.

Chris