If there’s hum in the recording or if you like send me a 192/24 sample right from the playback and I’ll see if we can make a quick utility for you.
Jamie Howarth
Plangent Processes
Please pardon the mispellings and occassional insane word substitution I'm on an iPhone
> On Jul 12, 2019, at 21:58, Tim Gillett <[log in to unmask]> wrote:
>
>
> I'm not familiar with the "gliding stretch" of Adobe Audition but if
> it allows you to set (by ear or even better by a reference on the tape
> such as hum) a start speed and end speed then assuming a linear
> increase in speed between those two end points, I guess it would
> replicate the original recorded speed. I'd first make the assumption
> that the original recorded speed didn't deviate due to slippage,
> battery fade etc. Only if the speed was obviously inconsistent after
> the initial correction of start and end points would I attempt further
> corrections.
>
> It wasn't just cheap/battery powered machines which used the rim
> drive system. On the Continent from the mid 1950's,
> Philips, Grundig and perhaps others used rim drive in mains powered
> dictation machines with essentially constant speed AC drive motors.
> Grundig tended to use their own proprietary tape cassette, and non
> standard reels, but the Philips models I'm familiar with used two 3"
> standard 1/4" reels inside a clear "cassette". The larger inner hub
> size was used. These machines come up on Ebay. Many were
> valve(tube) based machine. Philips continued the rim drive principle
> though to a 1/8" tape in another type of cassette, and then on to the
> tiny "mini cassette", also rim drive.
>
> https://obsoletemedia.org/el-3581/
>
> Tim
>
> ----- Original Message -----
> From:
> "Association for Recorded Sound Discussion List"
> <[log in to unmask]>
>
> To:
> <[log in to unmask]>
> Cc:
>
> Sent:
> Fri, 12 Jul 2019 16:41:07 -0400
> Subject:
> Re: [ARSCLIST] Reel-to-Reel tape problem
>
> Hello, J.D.,
>
> I tried thinking this problem through a while ago and it hurt my
> brain.
> You've heard from three experts who all said basically the same
> thing--with which I concur.
>
> What I thought I would add is a little thought experiment.
>
> These machines did not have a capstan and they pulled the tape by a
> motor attached to the takeup reel. For some reason it has been
> referred
> to as "rim drive" perhaps because the motor often contacted a rubber
> surface on the rim of the reel table to provide a "gearing" ratio
> from
> the motor to the reel table, rather than being directly attached to
> the
> spindle.
>
> So, let's assume that we have a constant speed motor that can deliver
>
> infinite torque (bear with my and hold your "tsk tsks"). If that were
>
> the case, you could calculate the actual speed by knowing the radius
> of
> the tape pack at time of recording, the speed of the motor and pi. As
>
> the takeup reel filled up, the tape speed would increase, so if
> you're
> listening on a capstan driven machine, the pitch would drop. Let's
> call
> this calculation (A).
>
> BUT, the motor does not have infinite torque. As the radius of the
> takeup reel tape pack increases, the moment arm gets longer meaning
> that
> the same amount of holdback tension may cause the motor to slow down
> a
> bit as it can't deliver all the torque that would be required. So
> this
> adjustment factor could be figured out, but the speed at the end of
> the
> tape will fall short of what you calculated in (A) above. Let's call
> this adjustment factor (B).
>
> So, at this point, the speed at any given point is (A) - (B).
>
> Now, some odd things enter in that will change this. As the (gasp
> zinc
> carbon flashlight) batteries discharge, the motor will not be able to
>
> deliver as much torque as the batteries will deliver less current and
>
> their voltage will drop compared with fresh batteries, so we have a
> third factor.
>
> And if this unknowable was not enough, the holdback tension was
> provided
> by pressure pads--usually against the heads--so this creates multiple
>
> additional factors for affecting speed:
> --the calendaring/polish of both tape surfaces will affect the
> friction.
> --the environmental temperature and humidity will affect the
> friction.
> --the cleanliness of the guides/heads will affect the friction.
>
> So, there you have a quick snapshot of the dynamics of this system
> and
> why fixing it in post in software is the best alternative.
>
> I reiterate what Ted Kendall said, "there were myriad reel-drive
> Japanese recorders around at the time, all of which were different
> between samples, never mind designs." And I might add, there were
> differences with the same recorder based on tape type, climate
> conditions, and battery condition. A fair number of these recordings
> originated in Vietnam in my experience, but thankfully a large number
> of
> the ones I have received were recorded with capstan machines. the
> Craig
> 212 was a classic of the era with a capstan.
>
> Cheers,
>
> Richard
>
>> On 2019-07-12 3:53 p.m., Scott Phillips wrote:
>> These would have been rim drive recorders, without a capstan drive
> roller. There is no fixed speed, it was determined by reel motor
> torque and the diameter of the amount of tape on either reel at any
> moment. Good luck with that, software is about your only available
> practical tool I know of..
>>
>>
>> Best regards,
>>
>> Scott Phillips
>>
>>
>> -----Original Message-----
>> From: Association for Recorded Sound Discussion List
> [mailto:[log in to unmask]] On Behalf Of J. D. Mack
>> Sent: Friday, July 12, 2019 1:30 PM
>> To: [log in to unmask]
>> Subject: [ARSCLIST] Reel-to-Reel tape problem
>>
>> I'm looking for some advice/info. I sometimes transfer reel-to-reel
> tapes to CD or digital files for my customers. Frequently, I receive 3
> inch tapes from the 1960s that start at one speed and gradually speed
> up or slow down substantially as the tape plays. The speed range is
> usually between 1 7/8 and 3 3/4, but never landing on either speed. I
> can correct for this using Adobe Audition's gliding stretch, but it
> takes quite a bit of trial and error. What sort of tape player would I
> need to hunt down to play these tapes correctly without having to
> resort to a software solution? My customers never have any idea what
> brand and model was used to make the recordings.
>>
>
> --
> 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.
>
> -------------------------
> Email sent using Optus Webmail
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