View Single Post
Old 6th May 2003
  #7
The Distressor's "daddy"
 
Dave Derr's Avatar
 

WHICH TAPE DECKS WERE MODELED IN THE FATSO?
(Quick answer: None Specifically)

Khai

I almost missed your post asking if there was a specific tape deck I tried to emulate. The answer is NO. However, I did buy a digital scope and had a couple Dat players that I recorded things onto for comparison. Then I put sine waves, square waves, and then music, both full program material, as well as snare samples, vocal samples, Bass tracks onto various tape decks. Some sources I just listened to, but most of the time, I would measure signals with my HP Analyzer, and would save waveforms onto my HP54600B digital scope (This started back in 97), and/or record onto my Dat player. There is also a wealth of documentation on tape deck frequency, phase, and transient response that I read up on.

The tape decks I looked at were an 3M M56 16 track 2 inch, a Studor A800, an A80, Otari M80, a Revox 2 track and even a Sony Cassette deck. I used Ampex 456 and 499 tape mostly. But I also remember 3m 996 was it and some BASF tape that escapes me right now. The general affect of all the tapes were very similar but the high end changed as experienced engineers know. Different bias settings could make huge differences as well as operating levels. Also, the Otari M80 had HX-PRO which attempts to counter the high frequency saturation of analog tape. Overall, I think the Studers had the best heads and most consistent performance, while the Otari's had some great electronics at a great price.

Honestly, its very scary watching 15KHZ sine waves come back off analog tape, all squigly and jumpy, changing amplitude from one part of the tape to the other! Its like ".. And I trust my music on that?" (laughing!). Even getting a good solid 1KHz was sometimes difficult on some tape. There would be fast amplitude modulation of a fraction of a dB continuously.

BUT, the nice thing was the analog tape added harmonics on the low frequencies, lost the sub freqs complettely, softened the high end when it piled up, and soft clipped in general, allowing more apparant loudness without peaking out. Its amazing the contortions engineers went to get a semi accurate signal back off tape. My 3M M56 machine had a pre distort circuit that would actually "anti-clip" what tape does. I think I generally kept that circuit clicked out when i recorded. It also had these giant output transformers that added 1% THD on low frequencies even without going to tape.

Whew - i think I am running out of "Posting Room". Good question Khai and sorry for the delay in answering.