I was hoping for more input from the tape-degradation experts on the list. I know Richardson's
treatment is very controversial with some people. I was _very_ skeptical, which is why I asked him
to treat that test tape for me. To be honest, I'm pleasantly surprised that it's still not sticky.
I'm not ready to say, I believe all his claims, but I am ready to say that more independent
scientific testing should be done, especially given that it's been tested and shown (by Goran
Finberg) and heard (by me and others) that baking, at some point, causes audio degradation. That,
too, should be tested in a more scientific manner. I'd like to know WHY the AM distortion increases,
heard by me and others as a "fuzzing out" of the sound quality. My theory -- totally a theory since
I don't have a powerful microscope or other tools to study it -- is the surface of the tape gets
less smooth from baking, and there's a tape-to-head contact issue or a sort of scrape-flutter is
being caused by less-smooth tape rubbing against the face of a stationary head. We also need more
scientific testing on whether cold/dry storage has any preventative effect on sticky-shed. Perhaps
the ARSC board could consider research grants, maybe working with AES and NARAS and perhaps the
government? One avenue I think is a dead end, which has had plenty of talk and speculation over the
years, is ever getting any reliable documentation on "the recipes" used to make the sticky-shed
tapes -- or even knowing for sure if "the recipes" varied over time during the sticky-shed era.
-- Tom Fine
----- Original Message -----
From: "Scott D. Smith" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, December 22, 2015 6:56 PM
Subject: Re: [ARSCLIST] One more sticky-shed data point - Richardson treated tape
>I can verify Corey's experience regarding the #3M mag film issue (which 3M was aware, and worked
>hard to rectify).
> A real nightmare, as it would tend to "hang" when going over the heads, causing all kind of
> disturbances in the Davis tight-loop on the recorders/dubbers.
> --Scott Smith
> Chicago Audio Works, Inc.
> On 12/20/2015 1:15 PM, Corey Bailey wrote:
>> I only have anecdotal evidence that Charlie Richardson's suspicions may be correct and it comes
>> from the world of magnetic film:
>> The vast majority of magnetic film, as we all know, was a tri-acetate base product and thus
>> suffers from vinegar syndrome (VS) over time. However, one of 3M's last offerings was a polyester
>> base, back coated product that yes, has the tendency to go SS. I have encountered the problem
>> more than once with that particular type of mag film and all of it has been stored in the best of
>> conditions. Other manufacturers offered polyester base magnetic film stocks that were not back
>> coated and do not tend to go SS.
>> Holiday Cheers!
>> Corey Bailey Audio Engineering
>> On 12/20/2015 5:24 AM, Tom Fine wrote:
>>> I should also mention, Charlie wanted me to send the tape back after the first transfer for
>>> "further processing." I decided, no, I want to see how it holds up in the real (reel) world,
>>> over time, under non-vault storage conditions.
>>> -- Tom Fine
>>> ----- Original Message ----- From: "Jamie Howarth" <[log in to unmask]>
>>> To: <[log in to unmask]>
>>> Sent: Saturday, December 19, 2015 10:54 PM
>>> Subject: Re: [ARSCLIST] One more sticky-shed data point - Richardson treated tape
>>> Very cool. Rad, scary, but if it holds up that's great.
>>> Please pardon the mispellings and occassional insane word substitution I'm on an iPhone
>>>> On Dec 19, 2015, at 8:54 PM, Tom Fine <[log in to unmask]> wrote:
>>>> Back in early 2014, I sent Charlie Richardson an old Ampex 7.5IPS alignment tape, which is on
>>>> Ampex 406 tape, circa 1970. The tape was definitely sticky-shed, in fact the first couple of
>>>> layers I wound out by hand pulled oxide to the adjoining backing layer. Richardson treated the
>>>> tape with his "Rezorex" process, which apparently uses a chemical peel to remove the back-coat
>>>> layer, which Richardson contends is the source point of sticky-shed. I transferred the tape in
>>>> May 2014 with no problems, then put it on a shelf in ambient metro-NYC indoor environment. That
>>>> first playback was on an Ampex AG-440B. I just rewound and played the tape again, this time on
>>>> an Ampex 352. Still no sticky-shed evidence, and the audio was fine (test tones were 10dB below
>>>> reference tone, for the most part, azimuth tones allowed stable adjustment). Richardson had
>>>> left a little bit of the end of the reel with the back-coat still on, and that tape was solidly
>>>> sticky-shed. I will keep on playing this tape once a year to see if it goes sticky again.
>>>> I think a more scientific test of this process would require sacrifice of both a sticky-shed
>>>> test tape and a high-fidelity music recording on sticky-shed tape. Although Richardson wants
>>>> tapes not to have been previously baked and played, which he contends damages the tape, I'd
>>>> want a reference transfer after one bake. Then let the back-coat layer be removed, and do a
>>>> transfer with the exact same equipment and compare both measurements and careful listening, see
>>>> if the chemical peel does any sonic damage. In the case of my old test tape, all I'm saying is
>>>> that the tones are at the announced levels, and this tape could be used in a pinch to align a
>>>> tape deck, although I'd want to bet on a modern MRL tape if it were for anything critical.
>>>> One other thing. The tape with the backcoat removed is not as thin as I thought it would be. It
>>>> seems to move through the transport just fine. I didn't observe any obvious edge-curl or
>>>> country-lane motion, and it fast-winds just fine through all the static guides on an older
>>>> Ampex transport.
>>>> I'd want to do more testing with very familiar high-fidelity music recordings to make sure the
>>>> process doesn't do any damage to audio, but for at least a year and a half, it does seem to
>>>> prevent a return of sticky-shed's mechanical symptoms.
>>>> -- Tom Fine