how do i fix an old dearmond tremolo control?

[freak scene]

got one, everything looks like it is working, but the glass bell type thing is dry, im assuming it had mercury inside it.  any way to get this working again?

looks like it would be a bad assed effect if i could get it working.

[Paul Perry (Frostwave)]

"In 1948 (perhaps a year or two earlier) he introduced the world's first effect unit for electric guitar, the Model 800 Trem Trol. This foot-operated floor-mounting unit comprised a mains voltage motor that rocked a small sealed bottle fitted with two electrical contacts and containing electrically conductive fluid. The variable frequency of the 'make and break' action of the mechanism created a type of tremolo effect. This effect unit was used by Bo Diddley and by many other artists."

If that is accurate, then it doesn't sound like mercury (which would just give a staight on/off). If you can get into the bottle, try a concentrated table salt solution.
What I'd do, is replace the mystery unit by a pot & see what value resitances you need for the range.
And, if it WAS just straight on/off, you can use one of those mercury tilt switches used in motorbike theft alarms. Or the metal ball in a cage used as a tilt alarm in pinball machines.

[PharaohAmps]

According to an interview of Billy Gibbons I read, the thing inside IS a vial of mercury.  In fact, in his book (Rock 'N' Roll Gearhead,) there is a picture of a DeArmond Tremolo Control, the brown one with the little handle on top.  I assume that the knob controlling depth is part of a voltage divider network that the signal runs through, and that the mercury switch breaks the divider's connection to ground.  It would give you less than a full on-off chop, but the modulation waveform would definitely be pretty square.

You can buy (or used to be able to buy) those switches at a variety of places.  These days your best bet is probably to find an old residential thermostat, the kind with the spiral of bi-metallic strip inside and the mercury switch on the end.  I've lived in at least 5 houses that had that kind of thermostat, so there must be millions of them out there.  Perhaps a salvage / thrift store (we have a Habitat for Humanity Re-Use Center here that's a great source for oddball junk used in houses.)

Good luck,
Matt Farrow

[freak scene]

thanks!

[freak scene]

what about just refilling the vial.  the general concensus seems to be mercury, but i found one account that stated he refilled it with windex and it worked wonderfully.

and would it matter in terms of a collector's standpoint if it had the original vial in it?  after some research all the mercury tilt switches i can find are metal cans (which while safer, does not carry as much "mojo")

what about just getting some mercury?