Andy Taylor's problem with not enough volume on the converted 3-speed
phono can probably be explained by the fact that many of the older
phono cartridges had an output of as much as 3 volts.  The later
ceramic phono cartridges had around 0.5 to 0.7 volt output.

I have, in the past, used a single transistor in a simple pre-amp to
get the output up to the desired level.  I believe I have in my
archives a suitable circuit diagram.  Another way would be to use
a magnetic phono pre-amp and then use a suitable attenuator net of
resisters to reduce the signal down to the 50 millivolts or so level
that the magnetic pre-amp expects.  Hope this helps.

Jim Cook