I think what Tom is saying, and I totally agree with him, is that there is no virtue in playing a historic tape on an historic transport;  modern transports treat the tape far more gently and have much less flutter;  however there is every reason to play historic tapes using the original restored playback heads and electronics or their equivalents.  If a tape was made on a machine capable of recording 18 to 18khz and played back on a machine capable of 40 to 40khz you have lost the bottom octave and gained an octave which contains no recorded signal.  As I've opined before, any tape specs I've seen seem to cover 10 octaves - a situation where the upper limit of reproduction is 1,000 times the lower limit.

db



On Thursday, March 27, 2014 3:40:03 PM, Dave Burnham <[log in to unmask]> wrote:


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>Sent from my iPhone
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>Begin forwarded message:
>
>> Hello Tom Fine,
>>
>> Let me comment on some of your good observations, which I have pasted-in below.
>>
>>> The idea of "playing vintage tapes on vintage tape machines" is a mute point nowadays.
>>
>> I wish this were so, but sadly it isn't. Witness that a fragile (and
>> obviously irreplaceable) Sinatra master was destroyed just last year,
>> simply by being played back on the wrong equipment. The machine in
>> question is regarded by some as being very modern, in relative terms.
>>
>> Sadly, there are many such cases, although understandably not widely reported.
>>
>> By the way, couldn't we argue that all analog tape machines could be
>> termed vintage today?
>>
>> Wouldn't it be more useful to define some of the basic tape transport
>> architecture classes that distinguish these machines from one another,
>> and then classify the various machines accordingly? For example:
>> Recorder/reproducer or reproducer? Servo constant-tension or constant
>> torque? Servo-capstan or hysteresis synchronous capstan? Force-guided
>> or precision guided transport path? Pin lifter or roller lifter at
>> headblock?
>>
>> For practical examples of what these differing machine architectures
>> might mean in historic transfer work today, consider an acetate master
>> that has the oxide layer falling off. Or a mylar master that is
>> exhibiting soft binder syndrome.
>>
>> Would mounting either of those master reels and re-winding on a
>> transport with fixed pin lifters be responsible practice?
>>
>> What about edge-forced guidance through a headblock? Or needlessly
>> pulling the fragile tape over an erase and then a record head? First,
>> do no harm.
>>
>>> By the time of all the later-generation professional tape machines,
>>> things like speed stability and scrape-flutter were well understood,
>>> so playback was more precise.
>>
>> Yes, achieving satisfactory speed stability was in many cases
>> accomplished by adopting constant-tension and servo capstan designs.
>>
>> But as I see it, the matter of scrape flutter is not so simple.
>>
>> The project leader for the Ampex ATR-100 certainly understood scrape
>> flutter, but he knew that precision guidance through the transport
>> would add tremendously to the manufacturing cost. Further, he
>> correctly understood that you could not insist that customers use only
>> certain brands of tape. (Especially if these were tapes not
>> manufactured by Ampex!) So forced guidance through the headblock was
>> designed in. It was a huge scrape flutter generator, yet regarded as a
>> necessity. And it remains difficult to argue that his approach was
>> wrong.
>>
>>> It adds up and it's audible.
>>
>> Correct. Scrape flutter is audible and the components of flutter add
>> vectorially. This makes the choice of the reproducer quite important,
>> exactly as you have observed. We have been saying (for about 20 years
>> now) that ideally, the reproducer's flutter contributions should be
>> lower than the recorded flutter on the tape, by an order of magnitude.
>>
>> I hope that re-issue producers always first listen to a historic
>> master played back on an ultra-low flutter reproducer, before
>> committing to trying to fix something with subsequent processing in
>> the digital domain. People are often surprised at what can be
>> retrieved from an old tape when it's played back on a great
>> reproducer.
>>
>> Fred Thal
>> ataestuder.com
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