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Hi, Corey, Very interesting. Just to be crystal clear, you were making analog to analog copies. Absolute polarity in that case is a non-issue as there are, in effect, two polarity reversals. The first one when you play the original tape backwards and the second when you play the backwards-recorded tape forwards (in essence backwards again). Obviously, one needs to flip the polarity in the digital domain as the file reversal should not include a polarity reversal, although if the function were designed for this purpose it COULD do both in one pass, but I don't think any do. Your results are in keeping with what I have heard for analog copies and I think since we are concatenating two complete passes through the analog tape chain that there is more of a reason to say this is good for analog copies than for digital copies. I really hope Tom (or someone) does some listening tests. I've done my share recently with the Satin software NR decoder. Cheers, Richard On 2/7/2016 3:03 PM, Corey Bailey wrote: > I used to routinely transfer 2 track music masters backwards. The > results were noticeably better than a transfer made forwards. The tapes > were non-Dolby encoded (I was never a fan of noise reduction for music > recording). Azimuth is absolutely critical. It has to be spot on as well > as the playback EQ calibration. This process was always done on the same > machine that recorded the master tape. Azimuth and playback EQ are > calibrated with the tape playing forward and then the tones are played > in reverse, recorded and observed. If there is any difference in the > recorded level of the source tones on the reverse copy, then the > playback alignment has to be re-checked and the culprit is usually > azimuth. I always adjust azimuth with a dual trace scope and overlap the > channels to insure absolute phase although there are a few ways to > calibrate azimuth and get it right. When it comes to the absolute > polarity of the copy, it was never an issue because the phase > relationship remains the same if all is adjusted properly, even though > absolute phase is reversed. Did many A-B listening tests with everyone > concerned and an overwhelming majority preferred the backwards transfer. > Those who weren't sure could usually not tell the difference. Then, of > course, there were those nervous producers who were afraid of anything > outside the box. > > I have never tried this with 1/4 track or 4 channel formats and Richard > Hess makes a valid point about the difference in 4 channel heads vs. 1/4 > track. I did try the process on a 2" 24 track tape and the results were > not great and I have to reason that it was an azimuth issue because > multi-track heads are never perfect. The 2" transfer was tried on an > AMPEX MM1200 which are fixed azimuth machines. > > Cheers! > > Corey > Corey Bailey Audio Engineering > www.baileyzone.net > > -- Richard L. Hess email: [log in to unmask] Aurora, Ontario, Canada 647 479 2800 http://www.richardhess.com/tape/contact.htm Quality tape transfers -- even from hard-to-play tapes.