Acetone Rhythm Ace FR-1 Analog Drum Machine Reparatur Service

This Ace Tone Rhythm Ace FR-1 Analog Drum Machine came in with hum in the audio signal. Customer told me he already re-caped the psu, but still got hum. While re-capping often is not a bad idea in these old machines, especially re-capping the psu, this does not always fix the problem(s). This Ace Tone here was heavily case modded. It was not in the original, but a smaller housing. Therefore the transformer was moved from it`s original place. And that was causing the problem. The transformer was placed way to close to the voicing board, so that the magnetic field of the transformer influenced (still lokking for a better translation) the voice coils on the voicing board. Placing the transformer in a different spot let the hum go away.