billow

Billow is a 5 button, six note, mellotron in a portable cassette player. It is a simple circuit bend, involving the removal of the motor fine tuning potentiometer and replacing it with an array of pots and buttons. The last pot can be set and with the switch next to it, set to the ‘default’ speed. And so the player can be used as a normal cassette player.

It can be purchased from me for 78 euros. If you are more comfortable with online stores, it’s available at https://tonetoys.etsy.com and at https://www.tindie.com/stores/poetaster/

Also features:

1. FM/AM radio (yeah!)
2. battery power with two AA batterys
3. comes with a usb adapter to power of a normal 5 volt phone charger.
4. works with most tape loop tapes, though not always a and b sides.

Midi billow

Heh. Well, a number of people asked if I could build a midi version. This is the prototype:

I designed it so that the simple resistor based motor control works exactly as in the original. So, 5/6 tones just on the buttons.

The midi input is via a 3.5 mm jack/adapter and the motor controller an LH9110. This requires using the 5volt input on the billow to get anything like decent range.

The controller is driven by a waveshare pi 2040 zero, just because (size). The code is implemented in circuitpython to make it fast and easy to iterate changes.

The range, given the motor, is limited. If you tune microtonal, 24 intervals, not log, so microtonal. If you try to tune it to notes, max 10 notes.

Also, the ’normal’ resistor button control works fine with long play tapes. But, using midi and slowing down ‘so’ much and speeding up so much means that it’s only usable with tape loops. Midi mode EATS long play tapes.

It’s fun :) But limited. I’m not sure I’ll sell these since I find it a bit limited. Perhaps a better motor controller chip? Perhaps another cassette player?