Magnavox phono console -> Guitar amp

[ZBod]

I bought an old Magnavox phonograph console for $30 today, for the tubes if nothing else. The turntable section is worthless, so I wired a guitar through it and it
sounds surprisingly good.

This thing powers on when the tonearm/turntable is engaged. There is no ON/OFF switch otherwise. As you can imagine, I'd rather not have this clunky carousel spinning around, as it adds unnecessary noise to the
unit.

There are three seperate stages in this thing. The power amp (2 x 5Y3, 4 x 6v6, 1 x 12AX7),
a seperate tone box (1 x 6AV6), and a preamp (1 x 5Y3, 2 x 6V6, 1 x 6AN8). All the tubes work
fine - old Magnavox and RCA tubes, two ten inch speakers...

So, my question is this: the turntable motor runs off the power transformer in the
pre amp section. I'm assuming I'll add the standby and power switch somewhere in this area.
There are three wires running from the preamp to the motor. If the connection between
the power transformer and turntable motor gets disconnected, what should I do with these leads? Maybe the more general question is what to do with unused leads so as not to ruin the transformer.

Naturally, there was no schematic with this thing and no user's manual.

Any ideas?

[Arthur B.]

I bought an old Magnavox phonograph console for $30 today, for the tubes if nothing else. The turntable section is worthless, so I wired a guitar through it and it
sounds surprisingly good.

Do you mean that the turntable will not play a record?

[Rob Mercure]

Any unused leads should be safely insulated and taped out of the way. While you state the turntable runs off the power tranny I suspect that the turntable is directly powered from the mains - there is probably a switch under the turntable deck that feeds power to the PT and turns the amplifier off (on) when the record reaches the inside leader track.

Your tube lineup is a bit odd with far too many output tubes and too few "preamp" tubes. Although there are sufficient stages for split load phase inverters you've still got at least two different output sections - probably one more than you'll need. Concentrating your work on the section that most interests you would allow you to focus on tweaking up the "tone machine" of your dreams - the 6AN8 section probably lends itself to a "Deluxish" tone monster.


Rob