I assumed, perhaps mistakenly, that he did not hear the warble during the playback and transfer of the tape - only when playing the digital file, since he referred to "the resulting digital recording" and not the analog playback. 



Gary Galo
Audio Engineer Emeritus
The Crane School of Music
SUNY at Potsdam, NY 13676

"Great art presupposes the alert mind of the educated listener."
Arnold Schoenberg

"A true artist doesn't want to be admired, he wants to be believed."
Igor Markevitch

-----Original Message-----
From: Association for Recorded Sound Discussion List [mailto:[log in to unmask]] On Behalf Of Ted Kendall
Sent: Friday, August 26, 2016 4:06 PM
To: [log in to unmask]
Subject: Re: [ARSCLIST] Sporadc Tape Warble

Sounds like the tape was catching on a spool rim or in guides on recording, causing a momentary slowing of the tape, and then releasing, causing a bounce of tape against head. Note how the initial pitch disturbance is upwards, indicating a slowing of recording speed. I fear you're stuck with it.

On 26/08/2016 20:48, CJB wrote:
> We  are digitising 60 year old reel-reel tapes.
> For this we are using an Akai DS40000 Mk 2 deck, a Behringer USB 
> digitiser, and Audacity. This is all connected to a Toshiba Qosmio G32 
> running Ubuntu (Linex).
> The tape plays smoothly with no sticky-shed or squealing.
> The recording was originally aired by the BBC on FM in the 1970s.
> The timeline is BBC Transmission > Radio FM Receiver > Reel-Reel 
> recording > Playback on same tape deck > Behringer digitiser > 
> Audacity > Saved as FLAC file.
> However the resulting digital recording has strange intermittent 
> 'warbles.' It is as though the tape was momentarily caught on 
> something.
> This is an example. Yes - some do like this kind of music!!! But it is 
> the quality of the digital recording that is of concern.
> Any ideas please as to cause?
> 28warble%29.flac
> Thank you -
> Chris B.

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