Inside-out means only that the groove starts at the centre and not at the edge.
Usually the recordist marked the label unless everyone knew that he cut his
discs one way or the other..placing the stylus at the outer edge will give you
the answer pretty quickly. It will either continue playing or fall off the edge.
As for whether it's aluminum or something else, hold it up to the light. If you
can see through it (translucent, usually blue) it's glass and hold it
incredibly carefully from now on. If it's not, tapping the edge with your ring
will tell you if it's aluminum or paper base. A standard 78 stylus (2.5 mil) is
fine for playing any of these discs unless you know it to be microgroove, and
for that to be the case it would have to be recorded at 33 or 45 and the
grooves would look the same as an LP.
Trey Bunn wrote:
> I have a 10" aluminum record with the brand name Perma Disk that I
> need to digitize. It has three holes (two in addition to the standard
> center hole) and instructions on either side to "play outside in" and
> "play inside out." Although the turntable I have isn't
> bi-directional, recording it backwards and then reversing the sound
> wouldn't be difficult.
> What I'm wondering is whether or not the equipment I have will work.
> I have a stylus for playing 78s (the disk is recorded at 78 speed),
> but that's for shellac disks, and I assume that there's a different
> stylus for aluminum. There is also one that I just found in a cabinet
> (this equipment was purchased long before I started working here) that
> says it's "2.7 mil, 78/transcription." Would this be the right one
> for the aluminum disc? And are those other two holes really
> necessary, or can I use the turntable we have? If I do need a new
> stylus for this, can anyone recommend the proper one and where to get
> Actually, I'm not even 100% sure this is aluminum. The disk is black
> like an LP, but the edge is metallic colored. I found a picture of
> the label at http://www.phonozoic.net/recordio/ (about 1/4 of the way
> down the page), and it appears that this company made disks of glass,
> steel, and simply "metal" in the third example (which most closely
> resembles the one I have, but my label is blue). Anyone have any
> Trey Bunn
> Audiovisual Conservator
> Emory University Libraries
> Preservation Office
> Atlanta, GA