I may not be getting this at all but the first thing I thought of was delay due to digital latency in the sound card.
how could that be if it doesn't show up in any of the baseline tests? i'm not being a jerk, i want to know, as i can't explain why one channel of the revox is trailing.
anyway i have graphs. oh boy do i have graphs.
first, baseline frequency response, left and right. i used a white noise file and then let the response graph settle. this is obtained by switching the dbx200's tape 3 (the sound card device) to line.
i'm going to consider this as my 'target' for the curve, assuming it's flat - not that i am under the impression that my electronics are perfect, but rather, this is as good as things get....i'm sure some of this is due to limitations of the sound card, the software, the white noise file i used, etc.....and some is my gear.
at the very least, whatever is going on, it's going on equally in both channels.
i took graphs of both decks, with all the various noise reduction schemes in place, but in the interest of not boring everyone to death, i won't post them all.
so first off is the ReVOX A77 - first just through the deck's electronics:
these curves are not symetrical like the baselines, most especially in the low end.
next the A77 monitoring it's recording:
yeegawds. Don't worry Mr. Studer, she will live again, i swear it.
next up is the Yamaha. here's the response just monitoring the signal through the deck's electronics:
well, it's not perfect, but a lot more symmetrical than the ol' A77. it's really a neat tape deck too. when you press record it plays some tape, calibrates iteself, and rewinds back to where it started and puts itself in pause. then it lights up "tuned". anyway, here's the response recording to a CRO2 tape:
hmm, i guess not a lot of HF response here either, although i'm listening to it recording right now, and it sounds truly excellent, whereas the A77 needs some work clearly, just from listening to it, without doing all this graphing.