Interesting post.
Please realize that ANY deck can have a different "sound" when used for recoding versus just playing back a tape. U47 and I found out long ago that decks, specifically Revox, can make a better sounding recording than they do when just playing back that or anther pre-recprded tape. We've (and I have to add most of you reading this) have found how "wanting" the playback electronics are in most decks, hence the flourishing of purpose-built, "outboard" electronics. Not many folks have delved into outboard record electronics.
Please understand that the decks we are talking bout here have TOTALLY separate record and playback circuitry - AND different heads. Gain structure in the amplification is different and you are "de-equalizing" when playing back versus equalizing/de-equalizing when recording/playback - using different techniques/components in those networks. PB and record heads are different - different physical configurations and low impedance for record and (usually) a good deal higher for playback. And there is the necessity to ad bias to the record head to linearize the whole process.
I've tried upgrading the audio parts in a few 1500's can say that they don't come close to a even a stock Studer. Part of the problem has to do with the heads. Panasonic made most of the heads for all of the Japanese recorders - confirmed by John French. I've done listening comparisons between the Technics/Nortronics/Studer/Nagra/Flux Magnetics heads and the best description of what I heard was a "loss of information" with the Panasonics - for a whole number of possible reasons like core material/lamination thickness/annealing/wire.
Charles
From a tape duplication perspective, I mentioned a long while back that a prerecorded tape is also ALREADY equalized per some "standard" curve - be it NAB/IEC/AES. When you Dupe a tape you use two decks, the playback decks' electronics amplify and RE-EQUALIZE it back to "flat". The second deck then amplifies and EQUALIZES it back to where it was or to fit another curve. Think of all the EXTRA amplification re/equalizing components involved to do this. What about the amplitude/frequency dependent phase leads/lags that this additional "futzing" adds the original "sound"? You are also throwing away gain while adding noise to the process. Why not just amplify the tape FLAT and feed it to the record head where the bias is added? I tried this on a [two] modified 1500 [one with a wired out Nortronics pro PB head and the other] with a Nortronics Record head and drove it with one of my preamps sans the playback EQ (but with a little EQ for the record head itself). It sounded really nice. If I were into trying to provide the ABSOLUTE BEST best tape duplication services, I'd use an approach like this - otherwise you are COLORING THE SOUND OF THE MASTER TAPES tape(s).
NOTE [ ] implies a later edit but now all the edited work have a line thru it?????????
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