I'm sure many of us (dreadfully) recall doing sessions on Ampex 300s and
having to edit two takes: one from the head of the reel and the other closer
to the end of the reel, and finding out that the speed changed at the edit
point.

Louis


-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:[log in to unmask]] On Behalf Of Tom Fine
Sent: 28 janvier 2011 20:30
To: [log in to unmask]
Subject: Re: [ARSCLIST] Test tones circa 1978

Here's another question -- why does hyper-accuracy matter in the age of
digital pitch correction?
Wow and flutter still matter, but if a tape transfers a few cents slow or
fast, why not just correct
it in the digital realm? You'll probably do better there than relying on a
mechanical transport
pulling tape to make a small speed adjustment.

Also, older tapes won't be hyper speed-accurate anyway. Old machines were
more loosey-goosey even
when new and I'm sure every old-school person on this list has
power-line-frequency horror stories
from back in the day.

To me, this is another one of those things where measurement and scientific
processes only go so far
in regards to music, versus using trained ears (or a tuning fork) to make
sure something sounds in
tune. And, knowing whether your machine is running exactly to speed is only
so useful, since you're
at the mercy of the original recorder's speed accuracy when you're doing
playback for a transfer or
dub.

-- Tom Fine

----- Original Message -----
From: "George Brock-Nannestad" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, January 28, 2011 8:13 PM
Subject: Re: [ARSCLIST] Test tones circa 1978


> From: Patent Tactics, George Brock-Nannestad
>
>
> Hi Tom,
>
> if the mains frequency is at the wrong speed, then a motor running off
that
> will run at the wrong speed. If you use a stroboscope light off the same
> supply, you will think things are o.k., unless the speed would be off even
> with the correct mains frequency. This is all assuming you use a
synchronous
> or hysteresis-synchronous motor. In the 1950s one of the broadcast
stations
> in Germany had a special crystal controlled mains supply for their
recording
> and reproducing equipment to avoid such problems. In the 1930s already,
> German portable film recording equipment had a stabilised frequency and
> voltage power supply for cameras to avoid the variable mains frequency.
BBC
> had record labels for instantaneous discs where you could mark the mains
> frequency at recording.
>
> With electronic speed control all of this was moot, and certainly Lyrec
had a
> crystal control for their speeds in the Frida model. The worst were the
tape
> recorders where you could accidentally record with the variable speed pot
> engaged. This was the reason that I made my added-on speed pot for my UHER
> 4000 go via a cable to a specially fitted jack, so that it could only ever
be
> on if you plugged it in.
>
>
> Kind regards,
>
>
> George
>
>
>> Hi Bob:
>>
>> Question on that -- if the lights are blinking at the wrong frequency and
>> the tape motor is thus
>> running a bit fast or slow, why wouldn't that register on a calibrated
>> strobe wheel? Won't lights
>> that aren't 60hz make the strobe pattern move just the same as wheel
speed
>> that's not right? Sorry
>> if it's a dumb question!
>>
>> -- Tom Fine
>>
>> ----- Original Message -----
>> From: "Bob Olhsson" <[log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Friday, January 28, 2011 5:20 PM
>> Subject: Re: [ARSCLIST] Test tones circa 1978
>>
>>
>> > -----Original Message-----
>> > From Tom Fine: "...Shai -- how about a stroboscope wheel in the tape
>> > path?..."
>> >
>> > I was told when I was working in motion picture post production that
>> > unfortunately power line frequencies are not a reliable source of speed
>> > calibration because they are adjusted to maintain the long term
accuracy
>> of
>> > electric clocks.
>> >
>> > A flutter tape is really the only solution.
>> >
>> > Bob Olhsson Audio Mastery, Nashville TN
>> > Mastering, Audio for Picture, Mix Evaluation and Quality Control
>> > Over 40 years making people sound better than they ever imagined!
>> > 615.562.4346 http://www.bobolhsson.com http://audiomastery.com
>> >
>
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