Re: [ARSCLIST] Risk assessment tool Q2

[Tom Fine <tflists@xxxxxxxxxxxxxxxxxxx>]

Steve Smolian covered a lot of the problems I've run into. Almost every cassette problem I've ever 
encountered has been mechanical (the shell) or mangled tape, which can be spliced out. I had one 
client with one badly mangled section of one cassette that they wanted transferred badly enough that 
they told me to get radical with it. My solution was to iron it smooth between two sheets of paper 
on low heat and then splice it back it. The end result was intelligable and complete. I do not 
recommend this in any but extreme cases and this tape had been more mangled and folded than 
stretched.

On older cassettes, a common problem is that the mechanics tighten up due to not-so-slippery slip 
sheets. And of course the old pad-comes-off-the-pressure-arm syndrome. All fixable by a shell 
transplant.

If I get a stereo music cassette that has bad edge warpage, I tell the client he'll do better not 
paying for my time and instead spending his resources hunting down a better copy. On a piano recital 
tape, we found that the inner track had enough info to make a mono transfer and get results that 
satisfied the client.

Another big problem in my own cassette collection is what I call Dolby C deterioration. Apparently, 
Dolby C is very sensitive to level in order to decode correctly. Level seems to fade over time on 
many tapes I made in the early 90's -- generally on Maxell and TDK chrome C-100 tapes. Dolby C is 
not happy with this and the sound results are not good. Whenever possible, I have re-borrowed that 
material and made CD copies. Dolby B doesn't seem as unhappy by level fades over time. As far as 
fidelity, the best-sounding music cassettes I have were made in a studio's dubbing room using an 
excellent phono chain and a Tascam 122 tape deck with Dolby B and HX on Maxell UDXLII C-90's. Even 
20 years later, those tapes sound fantastic.

As for metal tapes, I was never rich enough to buy into that whole thing. I was a CRO2 man all the 
way. I've heard some stunning sound-board tapes made on metal cassettes with Dolby B and HX. They 
sound every bit as good as 7.5IPS 2-track reel to my ears.

One final note on cassettes. My father's studio had one of the first cassette dupe places, beginning 
in the mid-60's. So I have a lot of "archival relics" from the very earliest days of mass-duped 
cassettes. They hold up surprisingly well over time. The tapes that seem to fall apart over time are 
many different types of Scotch cassettes from the 70's and 80's (all of the Scotch tapes in my 
collection have either failed mechanically or had some sort of oxide deterioration leading to 
terrible sound prematurely) and junky off-brand dictation garbage sold up into the 90's. We have 
hundreds of cassettes in our source material at work, mostly TDK D-90's and so far none have failed 
when needed, spanning about 10 years of use. The tapes are now so cheap -- around $1 each -- that it 
makes no sense to transfer a 10-minute interview to digital; it's not worth the cost of time/effort, 
so we just store the tapes.

-- Tom Fine

----- Original Message ----- 
From: "Casey, Michael T" <micasey@xxxxxxxxxxx>
To: <ARSCLIST@xxxxxxxxxxxxxxxx>
Sent: Thursday, January 05, 2006 2:14 PM
Subject: [ARSCLIST] Risk assessment tool Q2


Hi,

The second set of questions that I am looking for help with relate to
audio cassettes.

1. What problems are encountered in transferring cassettes? How does
deterioration manifest with cassettes?

2. Does the audio signal on a cassette deteriorate in any way over time?
[I have heard it suggested, for example, that the signal to noise ratio
gets comparatively worse over time on a cassette (compared to open reel)
but have not seen any data]

3. Do Type IV (metal) tapes exhibit any problems not found on other
types? Do chromium dioxide tapes deteriorate faster than ferric oxide?
[this has been suggested by one report]

4. Have you noticed any brand-related problems?

5. Have you noticed any age-related problems?

6. Problems with C-120s are well-known. Any similar problems with C-90
or C-100s?

Again, many thanks for your help.

Mike

--------------
Mike Casey
Associate Director for Recording Services
Archives of Traditional Music
Indiana University

micasey@xxxxxxxxxxx
(812) 855-8090

Co-chair, ARSC Technical Committee