[Ron Obvious]

Hello Bassman,

Dolby A was the original noise reduction hardware. It only dealt with reducing the noise above about 5 khz. The early filters and phase distortion was not that great. A number of years later, Ray Dolby came up with Dolby SR. Now the audio bandwidth was divided into 4 bands. Something like today's multi-band compressors. This allowed even more "broadband" noise reduction. I believe that Dolby A was about 10-15 dB on the top end only, while SR was about 20 dB overall. The electronics in the SR units were also of a higher standard - sounding much more transparent. Dolby A sucked all of the transients out of drums.

Dolby SR is much better. Use this. Only use Dolby A (rec mode) for that stupid add high end to the vocal trick.

Studer A80 alignment. 15ips IEC is fine. I would have your tech align the playback electronics for +6 dB over 185 nW/m = 0VU. This way with any of the modern high MOL tapes, you'll have lots of headroom in all frequencies.

The first thing you do when you get the machine back to your studio is make your own "test tape". Yes I know is not as good as the real one, but it will allow you to play with other alignments in the future ( i.e. +9 dB over 185nW/m = 0VU

From your console/daw oscillator - do a record alignment with 1khz, 10khz for bias, and high frequency, and then 50 hz for the low end. You'll notice that there is no rec low end adjustment. You need to adjust the 50 hz record level be adjusting the low frequency playback.

Once this is all done check the record head phase alignment, and also check how good 15 khz looks. It should a near 0 VU, also.

Now find a piece of clean unrecorded tape and make yourself and alignment tape. 1 to 2 minutes of each tone. 1khz, 10khz, 50 hz & 100 hz and 15 khz, just to see what's happening with these frequencies. Store this tape and only play it when you need to.

After this is all happening, now plug in the Dolby unit and do the input and output calibration. You send 1khz at console 0 VU to the Dolby unit. There are two screws on the way in. First one is to align to 0 VU on the dolby unit meter, next align the dolby "rec" output to the input of the Studer. Again adjust the Dolby rec cal for 0 VU on the Studer. This of course this needs to be done for the left and right channel "rec" and "playback". Note you are NOT touching the Studer at this point. > It's aligned already. Don't use the Dolby tone to align. Just put a bit of this at the end of the tones, so that the mastering guy knows that its a Dolby tape master tape.

Lastly, as someone had stated earlier in this thread, you could also try and align the Studer A80 to +9 dB over 185nW/m = 0VU. Then don't use any Dolby at all! Your tech will also mention that in Europe the IEC numbers for nW/m are just a bit different than the North America ones. I.E. 320 NA is 355 europe.

185nWm = 0vu original 1960's standard
250 = +3 dB
320 = +6 dB - in Europe IEC. = 355 nWm
520 = +9 dB modern tapes

Good luck.