Dan, As far as I know, there's no real speed mechanism, i.e., something analogous to the 33/45 switch on a modern turntable. The difference between 2 and 4 minute cylinders is that the 4 minute ones have roughly twice the amount of grooves per inch, like the difference between a wood screw (course) and a machine screw (fine). I've been in the market for a machine like that for a long time but still haven't found the right one for me, so I can't say for certain without personal experience, but I believe changing a phono from playing 2-minute to 4-minute involves separate reproducer assemblies (the piece with the stylus and diaphragm), each being designed to be placed resting against one of two long feedscrews (like headless bolts that rotate with the cylinder, parallel to the mandrel). They also have differently sized and shaped stylii specifically ground to play only the appropriate cylinders, so I would imagine trying to play a 2-minute with the 4-minute setup (or vice versa) would irreparably damage the cylinder.
I'm sure there are details I've missed here, but these are the guys to ask, so I'm hoping for this info to be corrected and/or clarified. (These are the guys to ask!) I only spoke up because I was surprised no one else had. Hope you're all having a fabulous weekend! Best, Robert Wright ----- Original Message ----- From: "Daniel Melvin" <[email protected]> To: "Antique Phonograph List" <[email protected]> Sent: Sunday, November 07, 2004 12:30 PM Subject: [Phono-L] 2/4 setup on a Columbia BFT I have a really nice Columbia BFT that has a 2/4 minute setup. Can someone tell me how this mechinism works? I have played around with it and it doesn't seem to make any difference what I do, the speed doesn't change. Thanks for any ideas you might have. Dan _______________________________________________ Phono-L mailing list [email protected] http://oldcrank.org/mailman/listinfo/phono-l
