i've had a Tascam 122 MKII as the main tape deck in my audio rack for i dunno 6 months now. haven't been spinning tapes much because it's out of calibration and i wasn't really liking the sound
figured this evening i might as well pull it out and get it calibrated in. do that, take it apart, find the service manual again, spend half an hour or so getting it on point according to the oscilloscope. play some music, still sounds like shit
now as mentioned i haven't been playing tapes in a while so i was like "maybe it always sounds like that". switch over to my Nak RX-505, play the same audio into it, cannot tell a difference between input and tape on the monitor switch (as it should be)
so i guess i've found out that the 122 needs a capacitor job or something, which isn't a big surprise, but also what the entire fuck was i doing having a RX-505 and using anything other than that in my main stereo this whole time
the boring but true answer if i recall correctly is actually just that the 122 has XLRs on the back and that works better with the rest of my gear because i can run balanced lines to / from the computer for it but also oh man it is NOT worth the audio quality difference