Turntable Modification

[Jim Patchell]

KA4HJH wrote:

> >    I have an old Philips 312 turntable.  I need to run at 78 rpm (this
> >thing is 33/45 stock).  Since it has a servo control for the platter
> >speed, I was thinking I could pervert this thing to run at 78.  Has any
> >body ever attempted this, and if so, were you succesful.  I would not
> >want to ruin a perfectly good turntable on a fools errand.
>
> Aside from the speed difference, which may be as easy as fooling with an
> oscillator, 78's use a different, larger stylus. I don't know what might
> happen if you try to use an LP stylus to play one. Maybe nothing, maybe it
> would damage something, maybe it would sound like crap.
>

    78's need a 1 mil conical stylus.  I have already found a source for
them.  I actually have two turntables that will do 78 RPM, but both of them
are wheel driven which means that there is LOTs of rumble.  The 312 is belt
driven, and while it is not what you would call a real high end turntable, it
is a lot more quite than the friction drive ones.  I also have an old
Rek-o-Cut, or something like that, but it doesn't go 78 either.

>
> --
> Terry Bowman, KA4HJH
> "The Mac Doctor"

    -Jim