Sony PR-150 and Graham Newton's binocular microscope and some dental
tools were the first clue to me of soft binder syndrome.
Marie had said to me she's using wet playback much less. You might ask
her to confirm, as I discussed it with her a few years ago.
Regarding IPA/ISO vs D5: D5 doesn't stink. It's not as harmful a
chemical to me. It evaporates more slowly, but does evaporate. It is
more of a lubricant than a solvent. It doesn't seem to dissolve anything.
Regarding cold playback.
A friend of mine in Pennsylvania puts his machines on the deck outside
his office on cold crisp late fall days and it works great, though a
killed his Studer C270 ? machine, it works well with his APR-5000. A
Studer A810 was unhappy in the fridge--the capstan seized up.
I have thought of the Peltier effect module and was thinking of
dismantling a cooler I haven't used in a quarter century but when I
thought about it, it didn't make sense because where does the condensate
go? Cooling down to freezing is below the dew point of my air most of
the year (40 % RH and a bit higher in summer and a bit lower in winter).
Using http://www.dpcalc.org/
Air: 20 °C 30 % RH DP: 2 °C
Air: 20 °C 40 % RH DP: 6 °C
Air: 23 °C 40 % RH DP: 8 °C
Providing thermal conductivity from the Peltier module to the head and
guides is difficult. Equally difficult will be the provision of thermal
insulation of the cooled surfaces to that giant heat generator they are
sitting on (aka the tape deck).
Prechilling the tape might work for only a few minutes. There isn't
enough mass in the tape to stay cold very long.
I do like your creative thinking. I can't think of how to emulate the
tunnel.
Cheers,
Richard
On 2021-02-25 9:33 p.m., Tim Gillett wrote:
> Thanks Richard and all for the replies.
>
> Even though I've not modified a machine as Marie did in NZ, I continue
> to wonder about the wisdom of the whole "lubrication" technique except
> perhaps as a last resort when all other techniques such as baking and
> cold play have failed, and I mean really failed not just because not
> implemented well enough, or the limits of baking or cold play have
> been reached. Especially since apparently the problem is not "lack
> of lubrication" as such but more "soft binder".
>
> Richard you said, "While I love the initiative demonstrated by Marie's
> isopropyl drip
> method (which she has indicated she's moved away from) I found better
> results with decamethylcyclopentasiloxane (D5, cyclomethicone,
> CAS 541-02-6."
>
> In what ways was D5 superior to Iso?
>
> I' m also not sure what Marie has "moved away from". The drip
> application technique? The use of Iso? Wettting technique itself?
>
> Given that it's not really a loss of lubricant but "soft binder", and
> that my experience so far has demonstrated on both cassettes and open
> reel tapes A MARKED LOSS OF HIGHS DUE TO SPACING LOSS, I'm tempted to
> abandon tests with wettting the head/tape interface and instead
> concentrate on mere cooling of the tape especially as it interfaces
> with the repro head.
>
> I read of practical problems trying to run an open reel machine
> inside a fridge. Do we need to limit ourselves to that approach? The
> entire machine doesnt need to be cooled, only the tape and repro head,
> and the minimum number of tape guides upstream of that repro head.
> Why not pursue techniques which ONLY COOL WHAT NEEDS TO BE COOLED and
> leave the rest of the machine unmodified and at usual room
> temperature, able to be used and monitored in the normal way? Has
> anybody pursued this?
>
> A couple of initial ideas for experimentation:
>
> 1. Cool the repro head via a small Peltier effect device attached to
> it.
>
> 2. Pre cool the tape by refrigerating it before playing.
>
> 3. Modify the machine to make the tape run in a small insulated
> tunnel, from the exit point on the supply reel to running over the
> repro head, which tunnel could also be cooled via Peltier effect
> device. This could also cool the minimum number of tape guides
> upstream of the repro head.
>
> Maybe such work has already been done or at least tried by people such
> as Specs Bros? I have no idea.
>
> Comments?
>
> Cheers Tim.
>
> ----- Original Message -----
> From: "Association for Recorded Sound Discussion List"
> <[log in to unmask]>
> To:<[log in to unmask]>
> Cc:
> Sent:Thu, 25 Feb 2021 13:33:52 -0500
> Subject:Re: [ARSCLIST] Tapes for testing wet play technique
>
> Hi, Tim,
>
> As you know, Marie's article (with photos) is published on my
> website.
> <https://richardhess.com/notes/2006/03/09/wet-playing-of-reel-tapes-with-loss-of-lubricant-a-guest-article-by-marie-oconnell/>
>
> There is a comparative analysis in my paper from the ARSC Journal.
> Not
> much has changed since then and the web page you allude to is meant
> as a
> supplement to this paper.
> <http://www.richardhess.com/tape/history/HESS_Tape_Degradation_ARSC_Journal_39-2.pdf>
>
> For those looking for the supplementary page, it's here.
> <https://richardhess.com/notes/formats/magnetic-media/magnetic-tapes/analog-audio/degrading-tapes/>
>
> A colleague is doing limited work with PEM-46x and may publish
> results
> later. I don't feel able to discuss it in more detail at this point.
>
> While I love the initiative demonstrated by Marie's isopropyl drip
> method (which she has indicated she's moved away from), I found
> better
> results with decamethylcyclopentasiloxane (D5, cyclomethicone,
> CAS 541-02-6.
>
> I just came across this 2008 report on D5 from Environment Canada and
>
> Health Canada.
> <https://www.ec.gc.ca/ese-ees/13CC261E-5FB0-4D33-8000-EA6C6440758A/batch2_541-02-6_en.pdf>
>
> My degrading tapes page mentions Sony PR-150, but at one point, it
> was a
> "poster child" of squealing tape, but later it seems some batches
> don't
> show it. I don't mention much about PR-150 as I've expanded so much
> on
> other squealing tapes, I should expand on this, too. See if you can
> find
> some that squeals.
>
> Cheers,
>
> Richard
>
> On 2021-02-25 12:06 a.m., Tim Gillett wrote:
> > I've revisited playing around with Marie O'Connell's wet play
> > technique but have come to a dead end as I need as a test sample an
> > actual squealing tape which does not respond to normal baking.
> Marie
> > mentioned PEM 469 of which I have many reels but the samples I've
> > tried seem to play fine. I also have much 3M 177 but reports on
> that
> > seem mixed. Perhaps that's related to the moderate Mediterranean
> > climate here in Perth, Australia. Richard Hess mentions 3M 175
> and
> > some others but what would be the most common known bad cases? I
> may
> > have some here in my collection but it would shorten the process if
> I
> > could narrow my search down to certain tape types known to squeal
> > regardless of baking.
> >
> > Thanks for any advice,
> >
> > Tim
> >
> > Perth, Western Australia
> > -------------------------
> > Email sent using Optus Webmail
> >
>
> --
> Richard L. Hess email: [log in to unmask]
> Aurora, Ontario, Canada 647 479 2800
> http://www.richardhess.com/tape/contact.htm
> Track Format - Speed - Equalization - Azimuth - Noise Reduction
> Quality tape transfers -- even from hard-to-play tapes.
>
> -------------------------
> Email sent using Optus Webmail
>
--
Richard L. Hess email: [log in to unmask]
Aurora, Ontario, Canada 647 479 2800
http://www.richardhess.com/tape/contact.htm
Track Format - Speed - Equalization - Azimuth - Noise Reduction
Quality tape transfers -- even from hard-to-play tapes.
|
