Hence, possibly, the Play Trim knob on NAD decks which put a variably
vicious lift in the top octave to improve replay on Dolby cassettes?
----- Original Message -----
From: "Richard L. Hess" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, January 14, 2011 5:00 PM
Subject: Re: [ARSCLIST] Association for Recorded Sound Discussion List
<[log in to unmask]>
> Hello, Goran,
> A friend of mine (who would rather not be dragged into more conversations
> about this) who worked in the Ampex Standard Tape Lab, and who is not part
> of this list, reported to me that no one could explain why, but some
> cassettes that were recorded would lose high frequencies if stored for
> about a year. The loss was substantial. While Don no longer has any notes
> on this, I have generally found his memory and knowledge to be reliable.
> His recollection is that the 15 kHz loss was in the neighbourhood of 10 dB
> in the worst examples.
> I have grilled him on this, and he is convinced that it happened and it
> was not due to external magnetic fields.
> One theory that was proposed at the time was magnetostriction due to the
> relatively small radii of the guides in the cassettes.
> He used Dragons and other top-end cassette machines in the lab. He was
> responsible for a while for manufacturing Ampex standard "test"
> [calibration] tapes for audio and video.
> On 2011-01-14 11:43 AM, Goran Finnberg wrote:
>> None of the high speed duplicated cassettes I still have, several 100,
>> none of my approx 60 BASF, Nakamichi and RCA test cassette tapes show any
>> change in level or frequency response either objectively or subjectively
>> the azimuth is very carefully adjusted on my Dragon, 582 or 682 Nakamichi
> Richard L. Hess email: [log in to unmask]
> Aurora, Ontario, Canada (905) 713 6733 1-877-TAPE-FIX
> Quality tape transfers -- even from hard-to-play tapes.