I recall conversations with Del Eilers where he commented that formulas were altered in some cases to reflect latitude. This had to do with differences in average temperatures and the components of the tape soup that were aware were affected by average temperatures. This came up when discussing cassette technologies. All companies were aware, I'm sure," of areas of the world where there was no air conditioning or even all-day-long electricity and how that affected the usability of the tape, much less longer term issues. . Perhaps Bill Lund could clarify this some. Also, perhaps, Mare O;Commell.
Steve Smolian
-----Original Message-----
From: Association for Recorded Sound Discussion List [mailto:[log in to unmask]] On Behalf Of Scott Phillips
Sent: Friday, January 29, 2016 3:29 PM
To: [log in to unmask]
Subject: Re: [ARSCLIST] Ampex 456 Grand Master: What To Expect?
Interesting!
For yet another data point, I have a client in Colorado that has several hundred 2" and perhaps 100 1/4" 456 tapes dating from the late 1970's through perhaps 1990. None of them have ever gone SSS at all, I've seen the tapes myself. On the other hand, I worked for years in the Miami Fla. area and saw plenty of the problem there. Both were constantly in climate controlled rooms except when removed for use. Storage temperatures were about 72 degrees F in Miami, more like 62 degrees F in Colorado, with a few rare dips colder during power failures during the winter. The big standout difference? The humidity in the case of the Colorado tapes was rarely over 25%, in Miami it was always much higher. These are not the only examples I've run across like this.
Not saying that is absolutely the reason, but the Humid storage and use conditions I've personally seen made a world of difference with 456. I will say I've never had to bake a 2" tape longer than 24 hours anywhere, but I don't deal with the quantity Marie or Richard do. Having said this, I haven't needed to repeatedly bake the same tapes over years of time, once a good transfer was made. I can easily imagine that it is different if repeated baking and transfer of a particular tape over and over the years might need longer and longer times, the chemistry of the degradation marches on....
The discussions on this topic have been most enlightening. There is so much to do, and the free flow of information and ideas helps us all.
Best Regards,
Scott Phillips
On Fri, Jan 29, 2016 at 1:23 PM, Marie O'Connell <[log in to unmask]> wrote:
> I am talking mainly 1/4 inch but also 2 inch Ampex 456.
> Marie
>
> On Sat, Jan 30, 2016 at 6:12 AM, Tom Fine <[log in to unmask]>
> wrote:
>
> > Are you guys talking about 2" 456? I haven't had this extreme a
> > problem with 1/4" 456 and 406. The one I've had to go 24+ hours with
> > is Scotch
> 227.
> > I just recently did some circa early 1980s 456, two 7" reels. They
> > played just fine and left no residue I could see on the cleaning
> > swabs, with 12 hours baking and 12 hours cool-down.
> >
> > -- Tom Fine
> >
> > ----- Original Message ----- From: "Ted Kendall" <
> > [log in to unmask]>
> > To: <[log in to unmask]>
> > Sent: Friday, January 29, 2016 11:12 AM
> >
> > Subject: Re: [ARSCLIST] Ampex 456 Grand Master: What To Expect?
> >
> >
> > This chimes with my own experience - days are required now where
> > once
> >> hours sufficed.
> >>
> >> About a week is the minimum bake that has had any real effect for
> >> some time now.
> >>
> >>
> >> ----- Original Message ----- From: "Marie O'Connell"
> >> <[log in to unmask]
> >
> >> To: <[log in to unmask]>
> >> Sent: Friday, January 29, 2016 5:20 AM
> >> Subject: Re: [ARSCLIST] Ampex 456 Grand Master: What To Expect?
> >>
> >>
> >> Hello
> >>
> >> See Ampex 456, bake Ampex 456, loathe it! We have hundreds of
> >> tapes in our collections on this stock, and it continues to come in
> >> with the new accessions.
> >>
> >> I bake them now for about 7 to 14 days at 52C for more success,
> otherwise
> >> I
> >> have to keep putting them back in the oven. 12 hours does nothing
> anymore
> >> and our vaults are humidity/temperature controlled. The really bad
> ones I
> >> do use a pellon wipe and then, if required, my isopropyl technique
> >> (last resort). My low friction Studers have eliminated much use of iso.
> >>
> >> Cheers
> >> Marie
> >>
> >> On Fri, Jan 29, 2016 at 11:13 AM, Richard L. Hess <
> >> [log in to unmask]>
> >> wrote:
> >>
> >> Hi, Steve,
> >>>
> >>> The Ampex patent has in its claims both 50 and 54 °C. That was
> >>> where
> the
> >>> higher temperature came from. It is still well below the Tg of the
> >>> base film. (67 - 81 °C) (
> >>> https://en.wikipedia.org/wiki/Polyethylene_terephthalate)
> >>>
> >>> Ampex patent here:
> >>> http://www.richardhess.net/restoration_notes/USP5236790.pdf
> >>>
> >>>
> >>>
> >>>
> >>> On 1/28/2016 4:10 PM, Steve Greene wrote:
> >>>
> >>> I used to bake 15" quad reels with a high degree of success at
> >>> 120F for
> >>>> 24
> >>>> hours, with a long ramp down time of another 24 hours before
> >>>> handling it.
> >>>> Knowing what I know now, I might go as high as 125F. 54C (130F)
> >>>> seems high to me.
> >>>>
> >>>> Steve
> >>>>
> >>>> Steve Greene
> >>>> Audiovisual Archivist
> >>>> Nixon Presidential Library and Museum National Archives and
> >>>> Records Administration
> >>>> (301) 837-1772
> >>>>
> >>>> On Wed, Jan 27, 2016 at 8:38 PM, Corey Bailey <
> [log in to unmask]>
> >>>> wrote:
> >>>>
> >>>> Hi David,
> >>>>
> >>>>>
> >>>>> My experience with baking 2" tapes comes from my experiences at
> Warner
> >>>>> Bros. Studios, Burbank, CA. As Richard Hess said: "456 is the
> >>>>> poster child for SSS" so, don't ask, just bake it.! Regarding
> >>>>> the question of how long to bake is dependent on the size and
> >>>>> type of oven, the number of
> tapes
> >>>>> to
> >>>>> be baked at one time and (obviously) the condition of the tapes
> >>>>> themselves.
> >>>>> The oven at WB is commercial grade, capable of baking 34, 10.5"
> >>>>> reels at a time. I've baked as few as two reels on up to an oven
> >>>>> full. For two reels of 2", the average baking time is 18 - 24
> >>>>> hours. I would suggest that you only bake as many tapes as you
> >>>>> can process in a day so that the stabilization process is as
> >>>>> fresh as possible. You mentioned leader breaks.
> >>>>> Expect any splices to have to be replaced after baking. Not
> >>>>> always
> the
> >>>>> case
> >>>>> but, build the labor cost into your budget.
> >>>>>
> >>>>> Cheers!
> >>>>>
> >>>>> Corey
> >>>>> Corey Bailey Audio Engineering
> >>>>> www.baileyzone.net
> >>>>>
> >>>>> On 1/27/2016 8:29 AM, David Crosthwait wrote:
> >>>>>
> >>>>> Hello Tom and Richard,
> >>>>>
> >>>>>>
> >>>>>> In my digging through a church archive yesterday with new
> >>>>>> clients,
> we
> >>>>>> uncovered many reels of 24 track on 2" among other audio tapes.
> >>>>>> One tape of interest I have with me, destined to a comrade here
> >>>>>> in town who is
> as
> >>>>>> passionate about vintage audiotape recovery as we are with
> videotape,
> >>>>>> is a
> >>>>>> 24 track on "Ampex Grand Master" 456 from 1988 in a cardboard box.
> It
> >>>>>> has
> >>>>>> track assignments within. The tape has leader breaks. In a test
> >>>>>> of sorts, we are going to link this up with a 1" C of the
> >>>>>> concert (same production, same date) to create a new stereo
> >>>>>> mixed version. I've done this
> before
> >>>>>> so I
> >>>>>> am familiar with the routine. The question to you two (and
> >>>>>> others)
> is:
> >>>>>> What
> >>>>>> should we expect from a stickiness standpoint (if any) from
> >>>>>> 1988 vintage "Grand Master" 456?
> >>>>>>
> >>>>>> The client has multiple reels of this concert so this is a test
> >>>>>> of sorts.
> >>>>>> The 24 track will create a ProTools session for the mix down
> >>>>>> and new stereo imaging (5.1?), to be done at the client's
> >>>>>> facility. I'm going to be remastering the 1" C today to file
> >>>>>> (it too is in stereo albeit with weak L-R imaging as viewed on
> >>>>>> the phase scope). It's a full orchestra
> with
> >>>>>> choir.
> >>>>>>
> >>>>>>
> >>>>>> Thank you.
> >>>>>>
> >>>>>> Best Regards,
> >>>>>>
> >>>>>> David Crosthwait
> >>>>>> DC Video
> >>>>>> Transferring NTSC, PAL& SECAM Two Inch Quad and Helical Source
> Tapes
> >>>>>> (and More)!
> >>>>>>
> >>>>>> http://www.dcvideo.com/what-we-do [log in to unmask]
> >>>>>>
> >>>>>> www.dcvideo.com
> >>>>>>
> >>>>>> Follow DC Video on Facebook: https://www.facebook.com/dcvideo
> >>>>>> Follow DC Video on YouTube:
> http://www.youtube.com/user/dcvideoonline
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>> --
> >>>>
> >>> Richard L. Hess email: [log in to unmask]
> >>> Aurora, Ontario, Canada 647 479 2800
> >>> http://www.richardhess.com/tape/contact.htm
> >>> Quality tape transfers -- even from hard-to-play tapes.
> >>>
> >>>
> >>
> >>
>
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