Using a "dimmer pedal" with a chord organ for volume?

November 5, 2005 2:51 PM

I just bought a Magnus Chord Organ on eBay. Trouble is, it's VERY LOUD and has no "volume" control, being nothing more than an electrically-powered fan. I would like to "modulate" the power so I can practice more quietly in my apartment. Is it possible to buy a "dimmer pedal", such as one might find on a torchiere, into which I can plug a standard electrical plug, and use this to "tone down" the organ by reducing the power to the fan? And might there be any hazards to the unit itself in doing so?
posted by mykescipark to grab bag (9 comments total)

i doubt you'd damage it by trying. it's likely to either stall or drop the volume.

dimmer switches (i don't know what a torchiere is) for lighting work by reducing the time that the AC voltage is actually "on", so the question is how this affects the fan motor. there is one kind of electrical motor - synchronous motors - that work on AC and spin at a fixed frequency. such a motor would simply stall if the power was reduced. however, i believe that cheap AC motors are not like that (and DC motors are not). so i think the odds are that a dimmer control would work just fine, as long it was rated at (or above) the power you need.

if you're talking about some other kind of switch (a rheostat? surely not) then i may be wrong. heck, i may be wrong anyway, but i'd give it a go.
posted by andrew cooke at 3:18 PM on November 5, 2005

Maybe you can make a mechanical choke to reduce the air delivered to the reeds.
posted by hortense at 4:18 PM on November 5, 2005

i thought of that too, but was worried you might overload/burn out the motor...?
posted by andrew cooke at 4:33 PM on November 5, 2005

i thought of that too, but was worried you might overload/burn out the motor...?

That seems extreemly unlikely.
posted by delmoi at 4:46 PM on November 5, 2005

The chances that it will overheat the motor are fairly high, actually, as most fan motors use the air moving over them for cooling. I would recommend shunting the extra air out into the room rather than choking the output of the fan. (A 'Y" in the air path that you can cover and uncover with strips of duct tape sounds about right to me.)
posted by wzcx at 5:37 PM on November 5, 2005

If you try a dimmer, turn it to full power before you start the motor and decrease the power once the fan is up to speed. Fan motors have a hard time getting started, and it shouldn't have current flowing through it without spinning. I'd try the dimmer first. It can generate some nasty interference, but that won't break anything permanently.
posted by springload at 5:51 PM on November 5, 2005

While finding out what one of these was, I found this:

The Magnus sucked air through the bottom. It had a damper wheel on its underside (to control how much it sucked, so to speak) and I used to like to move the wheel while I played to vary the tone color.
posted by armoured-ant at 6:22 PM on November 5, 2005

You're going about it all wrong, in my opinion. My organ has a little plastic piece over the "output" vent (where the sound leaves the organ). You can slide it partially over the vent to control the volume. Would that work on your model?
posted by electric_counterpoint at 6:48 PM on November 5, 2005

The fan vent seems to control the tone color, but barely affects the volume beyond a decibel or two. The concern about overheating the motor seems to be the most salient in terms of using a dimmer, so I'll have to be careful with that, I suppose. The next question being, where to find such a dimmer switch...
posted by mykescipark at 12:17 PM on November 6, 2005