The spring reverb is likely with another old tube amp organ pull. So pretty much disregard factoring that in. This all came in a box from a keyboard player friend.
Maybe a Leslie simulator?
Being where it is, and the associated large ceramic resistors (5W?) plus ventilated cover I would suspect a regulated power supply.
Not enough complexity for a Leslie Simulator which would be something akin to an old style Phaser.
Are those big black things inductors on the tag board? If so, could be some kind of all-pass filter. But again, I'm just a blind man pulling on an elephant's tail.
If it still won't get loud enough, it's probably broken. - Steve Conner
If the thing works, stop fixing it. - Enzo
We need more chaos in music, in art... I'm here to make it. - Justin Thomas
MANY things in human experience can be easily differentiated, yet *impossible* to express as a measurement. - Juan Fahey
They look like old "enamelled" style ceramic resistors to me.
We are used to modern rectangular white ceramic ones, but I´m old enough to remember this style.
And even older ceramic body *exposed* wire ones, think 40´s 50´s radios and PA amplifiers, some adjustable with a sliding metallic strap.
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