I would say, there are more scientific tests that could and should be done:
1. if one were to find a NOS tape, for instance an Ampex 406 or 456, that may have been kept in a
vault and by some miracle may not have ever gone sticky, this tape should be put in an ambient
environment and a series of recordings should be made on it, with a very good tape deck and someone
who knows how to align it and keep it running in excellent condition. The first series should be
sine-wave tones like a test tape. We can use these as a barometer over time to see if the tape
retains levels and perhaps some of the sine waves will be pure enough to justify careful visual
analysis. The next series of recordings should be high-quality full-range music that is very
familiar to the tester. Very careful listening should be done at the time of recording, A-B'ing
source and tape, and taking careful notes about what the recordist hears as far as tonal qualities
of instruments, "room tone," echo/reverb, low-level dynamics, etc. Then the tape should be allowed
to go sticky, presumably by letting it sit on a shelf in the ambient environment for a few years. It
should be verified, by tactile and other testing of the first few dozen feet, that the tape has
indeed gone sticky. Then the tape should undergo the Richardson backcoat-peel. Then it should be
played again, on the same machine, with the same careful listening to the music and careful analysis
of the tones. The test is for degradation from the Richardson treatment.
An even better test would have a person making two identical tapes on NOS sticky-shed stock that
hasn't gone sticky. After both tapes go sticky-shed in the ambient environment, one goes to
Richardson and one gets baked. Perform the same tests on both tapes. At least once a year from then
on, test both tapes for sticky-shed. The one retaining backcoat can be predicted to be sticky, and
thus would need baking. The Richardson-treated tape would presumably never go sticky again, and
should be playable out of the box. Test both tapes annually. And make sure to perform Goran
Finberg's tests for AM distortion on both tapes.
2. since a NOS 406/456 tape that has been under cold/dry storage and hasn't gone sticky yet may be a
"unicorn," the more likely real-world test is what I described before -- take a sticky-shed tape,
bake it, test it, turn it over to Richardson, test it again. The problem with that test, according
to my conversations with Richardson, is that he contends that the first bake permanently damages the
tape. My counter is, well then that first play has the damage "baked in" and serves as the root
basis for comparison, so as long as the chemical peel of the backcoat doesn't do any further damage,
it's a winner.
One thing that I think is proven (although those with a chemistry expertise my argue), as long as
the Richardson backcoat-removed tape never goes sticky-shed again -- the sticky-shed problem comes
from the back-coat, not other parts of the tape. In other words, it only lives on one side of the
tape, the non-oxide side.
Bottom line, I highly recommend those of you with better equipment, the ability to do
controlled-scientific testing, and more sticky-shed tapes, see if you can get Richardson to treat a
tape or two and do rigorous testing. Perhaps there's an ARSC grant, or NEH or NARAS or AES funding
to be found Or joint funding from all interested parties (ie anyone who has interest in collections
of back-coated tapes).
-- Tom Fine
----- Original Message -----
From: "Corey Bailey" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Sunday, December 20, 2015 1:00 AM
Subject: Re: [ARSCLIST] One more sticky-shed data point - Richardson treated tape
> This is great news!
> I've had an email dialogue with Charlie Richardson and he believes that his process could be
> automated. The problem is getting the investment capital and your experience may be just what some
> potential investor would be interested in. Perhaps there are others who have done the same as you
> and collectively it could be useful data.
> Corey Bailey Audio Engineering
> On 12/19/2015 5:54 PM, Tom Fine 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
>> 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