A mellotron is a tape player with a keyboard used to play a loop tape (or other tapes!) as if you were playing a sampler. So, the first kind of sampler that existed. This is a micro miniature version in a portable cassette player with a speaker.

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. See and hear some examples at https://poetaster.org/billow

If the switch is in the down position, you have 5 notes and if it is up, you have 6 notes with the highest being the full speed (so faster than normal) of the cassette player.

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.
5. Built in speaker!

I usually add some monster decals and a bit of decoration, but if you let me know I'll send you one without monster deco :)

I do not accept returns on this, BUT, I will do repairs within the first 3 months of you having the device for free if it develops a problem during normal use. You pay for postage to me, I'll cover the return to you.

Why did you make it?

Well, it's fun to play operas as if they were a keyboard instrument :)

What makes it special?

It has FM radio and an antenna! How cool is that!

Billow is also open hardware. You can use the design files (fritzting or gerbers directly) to make your own. See the link below.