Well no one's exactly beatin' down the door for this thing so I honked a reverb on top and sounds really good with my Yamaha keyboard here @ Casa de Birdman. Much louder than with normal guitar input.

Keyboards usually have a stronger output than guitars. Glad it's working out for you.

Well it's here until someone wants it. I guess advanced for 55 years ago, but of limited appeal now.

Well it's getting a better speaker next