Hi Abhi and Richard,
Abhi, with your Lafayette tape recordings have you tried looking
at the recorded magnetic patterns using a suitable magnetic reader or
viewer?
Richard, another machine, the Sony 521 had a small lever at the front
labelled "4 track/2 track" which altered (only) the head height to
allow a compromise playback of half track stereo tapes. Seemingly
like the Wollensak, it places the quarter track stereo head pole
pieces in the centre of the half track stereo position. Like the
Wollensak it didnt correspondingly alter erase head height so there
was potential to accidentally leave the lever in the wrong position
when making a recording.
Cheers,
Tim
----- Original Message -----
From: "Association for Recorded Sound Discussion List"
<[log in to unmask]>
To:<[log in to unmask]>
Cc:
Sent:Mon, 22 Nov 2021 15:42:24 -0500
Subject:Re: [ARSCLIST] Brittle Acetate Tapes (was 220V/50Hz 1/4" Open
Reel Audio Playback Decks)
Hi, Corey and Abhi,
In late 1962 or early 1963 (I recorded hours of JFK's funeral audio
on
it 58 years ago this week), I bought a Wollensak T-1616-4. It was a
really odd duck, but worked reasonably well.
It had a quarter track stereo combo record/play head made by Shure. I
don't recall the erase head. It had one complete channel of
record/play
electronics from mic in to 10 W power amp. There was an add-in
one-tube
chassis that was the head preamp which needed to feed a separate
amp-speaker combination. While there was a small power transformer,
the
10 W power amplifier was modeled after the AC/DC table radios and had
the whole power amp run directly off the mains.
This shows some pictures of the 1616-4
https://www.ebay.com/itm/313588550900 (not my auction)
and I've collected a few things that I have here:
<https://www.dropbox.com/sh/7wvowq62e9o5d17/AADOA9TqRJCej268l9wmj1kUa?dl=0>
The T-1515-4 manual shows at the end the track alignments, and the
eBay
photos above show the track wheel. Other manuals in the folder might
provide a better exploded view of the head assembly.
While there are differences between the 1500 and the 1600 it is
mostly
in the transport control. The 1600 was solenoid controlled for more
remote control and a lighter touch on the keys The 1600 could also
(with
the help of 1/8-inch foil tape) do auto repeat.
The 1500 was introduced in 1959 and the 1600 in 1960
I started to go thru the math of the head height adjustment to see
how
it worked out. It does work. So if you want to get caught up with
mils
(thousandths of an inch), have at it. Otherwise look at the pictures
in
the manual at the Dropbox link.
In the head assembly, there was an "elevator" arrangement (hence I
knew
that was possible when I had John French make one for my APR-5000
with
an 8-track four-channel head). The Wollensak elevator was run by a
Delrin disk which protruded out of the side of the head assembly and
was
marked A 2TR B. In the A position, the quarter track R/P head (and
presumably the erase head) was positioned so that the left head
channel
aligned with track 1 and the right head channel aligned with track 3.
In
2TR, the head was lowered slightly, presumably just enough so that
the
two quarter track head channels were completely on the professional 2
track tracks. This would probably have been adjusted for 75 mil
tracks,
since Ampex sort of ruled the roost in that era.
One can check if this was even possible by looking at
https://www.richardhess.com/tape/quarterinch_lrg.gif
Quarter track has 43 mil tracks and centre-to-centre of the 1/3
stereo
pair at 134 mils. That implies 24 mil guard bands...
Checking that math, 43x4+24x3 = 244 mils out to out.
Doing the same with the Ampex format, the two tracks are on 156 mil
centres and the track is 75 mils, so the guard band is 81 mils. This
gives an out-to-out dimension of 231 mils.
Normally, the top of the quarter track right channel head would be
137
mils from the top edge of a 250 mil tape, and the bottom of the left
channel would be 46 mils below the top of the tape.
The Ampex 2-track tape would have the bottom of the left channel 84.5
mils below the top of the tape and the top of the right channel 165.5
mils below the top of the tape.
So depressing the quarter track head assembly by 28.5 mils would just
put the top of the right head at the top of the Ampex two track right
channel.
This would put the bottom of the quarter track left channel at 74.5
mils
below the top of the tape, which allows a 10 mil window, so the ideal
depression for the 2 TR position would be 33.5 mils.
Continuing on, in order to go to the B position, the full 134 mil
centre-to-centre spacing of the quarter track stereo pair would have
to
be covered, or the distance between 2 TR and B would be 100.5 mil
Roughly, the A-2TR is roughly 1/4 of the total depression and the
2TR-B
depression is 3/4 of the total which is in keeping with what I
recall--it was harder to go to B as you were fighting a spring.
The actual elevator mechanism was a ramp molded into the bottom face
of
the Delrin wheel and a small ball that ran in a cup at the top of a
post
on the head assembly.
Being a fully mechanical assembly, this would not reset on power on
so
you'd record in the position that it was left in, and I suspect that
this little assembly wasn't stable after many uses.
Cheers,
Richard
On 2021-11-22 2:31 p.m., CBAUDIO wrote:
> I have about 90 tapes in the studio that were recorded on a
Wollensak
> model 1500. That particular model was 1/2 track, mono.
>
> Best,
> CB
> Corey Bailey Audio Engineering
> www.baileyzone.net
>
> ------ Original Message ------
> From: "Abhimonyu Deb"
<[log in to unmask]>
> To: [log in to unmask]
> Sent: 11/22/2021 2:00:44 AM
> Subject: Re: [ARSCLIST] Brittle Acetate Tapes (was 220V/50Hz 1/4"
Open
> Reel Audio Playback Decks)
>
>> Hi Tim and Richard,
>> Tim, the Lafayette tapes were recorded on a Wollensak recorder.
I'm
>> afraid I don't know much more than that. However, I suspect that
the
>> tracks 2 and 3 vs. tracks 1 and 4 issue is due to lack of
maintenance
>> of the recorder during the 4 or 5 years that the recordings were
made
>> rather than any compatibility issue between different formats.
>> That's because the tracks issue isn't consistent across all of the
tapes.
>> There's another factor that might be significant. Like I said, I
am of
>> Indian origin. My uncle (father's brother) went to the U.S. as a
>> graduate student in 1958 and came back to India in 1960, bringing
the
>> Wollensak and 12 Lafayette blank tapes with him. At the time, it
was
>> almost as if he brought a spaceship from Mars!
>> My father says that they never demagnetized the heads. They did
clean
>> the heads regularly but sometimes it was with aftershave lotion
>> (gasp!) or something similar.
>> The tapes are numbered 1 to 12 and were recorded mostly in that
sequence.
>> If I had to find a pattern, it would be that the earlier recorded
>> tapes are generally better on track 1 and later tapes are
generally
>> better on track 2.
>> Richard, I had read about your experience with the carbonyl iron
tape
>> in one of your papers a year or two ago (or maybe on your blog?).
I
>> tried your solution myself more than once, also with varying
degrees
>> of success.
>> From my experience, I can't find any pattern to the cupping
problem.
>> Could it be a maintenance issue? There was no cupping problem at
all
>> with the EMI acetates in Gramophone Company of India's archive.
>> On the other hand, I have seen this problem consistently on tapes
from
>> other sources and of varying brands that were not well maintained.
My
>> Lafayette tapes have no cupping problem at all. They were just
kept on
>> a bookshelf (in their boxes) for the past 50 years.
>> The whole subject is really mysterious and so much fun!
>> Best wishes,
>> Abhi
>> --------------------------------------------
>>
>>
>> Abhimonyu DebAudio Consultant and Digitization
>> Specialisthttps://www.linkedin.com/in/abhimonyudeb
>>
>>
>> On Sunday, 21 November, 2021, 11:48:43 pm IST, Richard L.
Hess
>> <[log in to unmask]> wrote:
>>
>> Hi, Abhi and Tim,
>>
>> Great discussion. The cupping is a real issue, but so is edge
waviness.
>>
>> On the suggestion of Friedrich Engel (retired BASF Historian), I
once
>> reviewed the only carbonyl iron tape I've ever seen. This was one
of the
>> first Magnetophon experimental tapes from circa 1935. It was so
badly
>> cupped that it was like a carpenter's steel tape and could support
>> itself extending from the reel.
>>
>> Hydration was Herr Engel's suggestion, I tried about 24 hours with
the
>> tape in a pancake form on a support over about an inch of water in
a
>> sealed container. It ran beautifully and was more like a satin
ribbon
>> than a tape measure.
>>
>> HOWEVER, I have repeated that once or twice since with far less
success.
>> The hydration probably reduces the strength of the tape.
>>
>> The worst over-hydration I've ever seen was a damp 1-inch Scotch
201
>> acetate tape. The acetate had swollen so much that the first half
inch
>> at the hub had been deformed and the closest layers had been
forced
>> through the slot of the hub, causing a bump. Of course it was
worse on
>> the track one side (which was recorded while only about five
tracks had
>> been used) and the tape had been wound tails out so the pack was
tight
>> and the first song of the album was most damaged!
>>
>> I put a pressure pad hard against the head (while adding extra
pressure
>> to the pinch roller to keep the tape on speed). My hands were very
>> cramped a half hour later. Then Paul MacDonald from Cape Breton
Island,
>> Nova Scotia who is a musician and excellent recording/mastering
>> engineer, spent days with it picking out a similar piece of music
to
>> cover the bumps using Sound Blade software. It turned out
beautifully.
>>
>> If the edges are wavy, then certainly tracks 2 and 3 would be a
better
>> choice, if the cupping is tamable.
>>
>> It is such a difficult line to draw between doing no harm to the
>> original and capturing the best possible transfer which will
likely be
>> the last transfer made (unless you really miss the mark). If you
are
>> doing risky procedures, it is important to inform the clients
about the
>> problems and risks before proceeding.
>>
>> Cheers,
>>
>> Richard
>>
>>
>> On 2021-11-21 4:55 a.m., Tim Gillett wrote:
>>> Hi Abhi,
>>>
>>> I suspect your experience with the old acetates is common. When
>>> brittle they can break easily but at least they break cleanly
and
>>> can be spliced back together again. The other issue which is
common
>>> is "cupping" on the oxide side. The top and bottom edges of the
tape
>>> are OK on the tape head but the centre section doesnt want to
sit flat
>>> so the sound is often muffled or weak. We can increase the tape
>>> tension across the head but it risks breaking the tape.
Sometimes
>>> a temporary felt pressure pad, or small artist's brush, or even
a
>>> fingertip as you did can be used to press the centre section
against
>>> the head.
>>>
>>> The problem you mentioned with the Lafayette acetates could be
that
>>> they were recorded on a Brush Soundmirror machine which only
recorded
>>> in the centre of the tape, leaving the top and bottom edges
>>> unrecorded. A "cupped" acetate tape is the worst for this as it
keeps
>>> that most important part of the tape off the head. The reason
the
>>> Studer machine didnt play them well is probably that it was an
NAB
>>> half track machine which would have missed the centre part of
the
>>> tape. You're right that tracks 2 and 3 of a quarter track
machine
>>> would read it much better. Actually a very good playback
can be
>>> obtained from a Soundmirror tape with a four track (four
channel) 1/4"
>>> head using tracks 2 and 3.
>>>
>>> Best wishes,
>>>
>>> Tim Gillett
>>>
>>> Perth, Western Australia
>>>
>>> ----- Original Message -----
>>> From: "Association for Recorded Sound Discussion List"
>>> <[log in to unmask]>
>>> To:<[log in to unmask]>
>>> Cc:
>>> Sent:Sun, 21 Nov 2021 04:58:17 +0000
>>> Subject:Re: [ARSCLIST] 220V/50Hz 1/4" Open Reel Audio Playback
Decks
>>>
>>> Hi Richard,
>>> Wow! You have no idea what it means for a little guy like me
to
>>> contribute to this forum!
>>> First, just a very quick background. Although I was born and
brought
>>> up in the U.S., I spent all of my adult and professional life
in India
>>> (I am of Indian origin).
>>> I used to work in the recording studio of the Gramophone
Company of
>>> India. It used to be a wholly owned subsidiary of the GC of UK.
Later
>>> it became independent.
>>> GC of India has a tape archive with acetates starting from
around
>>> 1955. They are almost entirely EMI tapes and are in excellent
>>> condition. There’s no problem of brittleness and they play
fine on
>>> A80’s and 807’s.
>>>
>>> Now I work independently, usually with smaller archives or
individual
>>> collections. The name brand tapes that I get, e.g. Scotch 111
or
>>> 141, usually play fine on my A807. However, given the tropical
>>> climate in India and the lack of maintenance of the tapes,
warping is
>>> a frequent problem.
>>> A few years ago, I inherited a dozen Lafayette brand tapes
from my
>>> uncle. The tapes were purchased in 1960 and recorded between
1961 to
>>> 1965.
>>> These tapes are mostly brittle. Instead of A807, for most of
these
>>> tapes I had to use an Akai GX-4000D quarter track deck to play
half
>>> track recordings. Yes, I know I broke every rule in the book
but I
>>> couldn't think of any other way.
>>> Interestingly, for some of these tapes played on the Akai, I
got a
>>> better playback from tracks 2 and 3 compared to tracks 1 and 4.
Of
>>> course, I had to reverse them on my DAW.
>>> A few years ago I got an acetate similar to your Vermont tape.
I
>>> actually had to unwind several hundred feet of tape from the
reel,
>>> somehow thread the tape onto my Akai without any reels on
either side,
>>> and hold my index finger softly against the playback head while
>>> playing.
>>> So, basically, the brittle acetates that I've encountered are
due to
>>> lack of maintenance or a cheap brand of tape.
>>> Coming back to Dave's original post, I was thinking to myself
when I
>>> first read it that it might be nearly impossible to find a
machine
>>> that can satisfy all of his conditions. But, then, I don't have
any
>>> experience with the ATR 100 or APR-5000.
>>>
>>> Best wishes,
>>> Abhi (short for Abhimonyu)
>>> ------------------------------------------
>>>
>>> Abhimonyu DebAudio Consultant and Digitization
>>> Specialisthttps://www.linkedin.com/in/abhimonyudeb
>>>
>>> On Saturday, 20 November, 2021, 09:53:59 pm IST, Richard L.
Hess
>>> <[log in to unmask]> wrote:
>>>
>>> Hi, Abbimonyu,
>>>
>>> This issue comes up in regard to many different machines. When
I had
>>> my
>>> A80s, I used them for acetate tapes on a regular basis. I
haven't
>>> used
>>> an A807 for a long time (as I preferred the A810 over the A807
for
>>> many
>>> reasons, and the A80 over the A810).
>>>
>>> In many respects, I think that the Sony APR-5000 is the
gentlest of
>>> the
>>> list I posted. On the other hand, I had no bad feedback from
the
>>> two
>>> A807s (refurbished by Roger Ginsley) that were sold into an
archiving
>>>
>>> project in Pakistan to use alongside their Tascam BR-20s
(which I did
>>>
>>> not suggest for the current project because many versions were
not
>>> made
>>> with power supply voltage selection).
>>>
>>> However, to answer Tim Gillette's rephrasing of the question,
we
>>> might
>>> consider machines that start the capstan motor when going into
play
>>> so
>>> you are not banging the stopped tape into the full-speed
capstan. The
>>>
>>> Sony APR-5000 works that way and mutes the audio for a short
period
>>> of
>>> time at startup.
>>>
>>> You weren't missing something and it is good that you posted.
Perhaps
>>> I
>>> didn't provide enough weight to that criteria.
>>>
>>> I'd be interested in hearing more about the fragile acetate
tapes
>>> that
>>> you encounter as I've been surprised at how well the Scotch
111 and
>>> Audio Devices acetate tapes have held up. I've even been
pleased with
>>>
>>> the paper tapes I've transferred as well. The only really
fragile
>>> acetate tape I've come across was one that sat behind a wood
stove
>>> through several Vermont winters. One face was welded together
and
>>> broke
>>> on ever rotation of the supply reel.
>>>
>>> The one thing that seems to fail for me are splices onto paper
>>> leader. I
>>> have to remake all those splices after baking in many
instances, but
>>> that's with back-coated polyester tapes.
>>>
>>> Cheers,
>>>
>>> Richard
>>>
>>> On 2021-11-19 8:41 p.m., Abhimonyu Deb wrote:
>>> > Given the notable list of people who have replied so far,
normally
>>> I would keep my mouth shut.
>>> > However, I do think everyone is missing an important point.
>>> >
>>> > Dave mentions that the machine should be able to play
fragile
>>> acetate tapes. The A80’s, 807’s and Otari 5050’s that
I’ve
>>> worked with would fail miserably here unless I’m missing
something.
>>> > Abhimonyu Debhttp://linkedin.com/in/abhimonyudeb
>>> >
>>> >
>>> >
>>> > On Saturday, November 20, 2021, 6:42 AM, James Perrett
>>> <[log in to unmask]> wrote:
>>> >
>>> > On Sat, 20 Nov 2021 at 00:55, Richard L. Hess
>>> <[log in to unmask]>
>>> > wrote:
>>> >
>>> >>
>>> >> Long ago, a company I think called
>>> >> "DarkLab" in Germany made EIA to DIN adapters out of
plastic.
>>> >>
>>> >>
>>> > They still make them and sell them on Ebay. I bought some a
few
>>> months ago
>>> > but haven't used them yet.
>>> >
>>> > James.
>>> >
>>>
>>> --
>>> 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.
>>
--
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
|
