Post 16: An Electric Amplified Organistrum?

   I received yesterday a little digital amplifier that packs a lot of power for only 13 bucks. On paper, they say 100 watts, but that would be with a 24V power supply. 

       Still, using a weak single coil ANILCO pickup, an acoustic guitar preamp/equalizer, and connected to one of my big 8 ohm stage speakers,  it does a pretty decent job. There is a fairly loud 60hz hum that can be controlled to some extent with the equalizer. 

     Grounding everything and using a humbucker pickup should help get rid of it. A 24 volts power supply would make it louder. And the amp is supposed to be able to handle a 4 ohm speaker, so I will try connecting my two big 8 ohm speakers in parallel.

    I had a little 3D printer that was dropped and broken, so I cannibalized it and used a 6mm rod and flange to mount the thicker wheel on a rough plywood frame sitting in a box to which the long double-bass stick with a single screw on the left-back corner(red arrow). By swinging the stick a little, the strings can be brought in contact with the rotating wheel driven by the little 50 RPM geared electric motor(arrow). This motor is placed at the end of a long shaft using a flexible coupling, so it is far enough from the pickup not to cause hum, and the speed can be lowered with a controller.

      The wheel can easily be raised or lowered, and moved laterally on the shaft to test its attack angle and location in relation to the bridge and the pickup. I have to admit it is hard to get a reliably beautiful sound, and it often sounds awful when the low string stays against the wheel. It also seems to sound a different note that when the string is plucked. The smaller string sounds much better, but I am still not happy with it. The tone is OK when the wheel is brought only very briefly against the strings and they are left to sound free. It will take a lot of trial and error to make it work to my satisfaction. And I don't think I want the strings of the instrument to stay in contact with the wheel. 

        What I am envisioning now is a vertical instrument, with a motor mounted on a round base driving a bigger wheel rotating at about 25 RPM. A dozen of one string sticks would be attached to the base so they stand vertically with the strings close but not touching the wheel. There would be just enough flexibility so any stick could be pushed against the rotating wheel, and naturally spring back to position. It may take a rubber band or a spring to help them. Ideally, I see an aluminum instrument with a heavy aluminum round base, a stronger geared motor driving a 12" aluminum wheel with a fiberboard ring at 30 RPM. The sticks would be aluminum tubing 1" in diameter and 1/8" thick, with tuners mounted near the top end. A brass ring would act as the nut, and a tipped brass screw would serve as a fixed adjustable bridge. Another option might be to use single hardtail bridges with adjustment screws like these:

        The strings would then be close to the tubing, so each stick would have a humbucker pickup mounted on a bridge ABOVE the string on the inside of the instrument. 

         It would also be good if the sticks had some up and down adjustment. There would of course be long 5ft ones with double-bass strings, and shorter ones with cello strings. That would range from a very low C to possibly an A on a cello G string, two and a half octaves or so.