I would start by determining the track format. You can use a Mag
Viewer to do this. Once the track format is known, you will then have
an idea if the material was sourced on a consumer, "prosumer" or
professional machine and what type of play head configuration to use.
15/16 Recording speed was available in mono, two track (from modified
professional equipment) and one-quarter track from various consumer
recorders. The recording speed was used primarily for voice
recordings (as previously mentioned) and some radio stations used
modified pro decks using 10-1/2" NAB reels for broadcast logging
although 1-7/8 & 3-3/4 IPS was more common for logging tapes.

Cheers!

Corey Bailey
Corey Bailey Audio Engineering

At 10:04 AM 1/12/2011, you wrote:
>Hello, All -
>
>I've run up against an interesting scenario (for us, anyway) and I'm
>asking for some feedback from the collective wisdom of this group.
>
>We've been doing a lot of our own digitization, but we've now run
>across a reel to reel tape that was recorded at 15/16 speed. It
>doesn't appear as if any of our reel to reel recorder/players offer
>that as an option, so, obviously, we'll need to send it out.
>
>How common was this recording speed and are there any general
>assumptions I might be able to make about the circumstances of the
>recording (i.e., Were there consumer-grade recorders available with
>this speed option? Years it might have been a popular option?)
>
>Thanks in advance --
>
>Stephanie George
>Archivist
>Center for Oral and Public History
>California State University, Fullerton
>(657) 278-3693
>[log in to unmask]