purchased a used 1990ies #alesis #midiverb III for cheap. it's a reverb/delay with MIDI control. but it doesn't work, the "CLIP" LED is constantly lit.

found a service manual with a partial schematic online, so I started digging. turns out, the 12V pos and neg voltage rails are broken. the LM7812 and LM7912 both short their input, but they're protected through diodes that's why the 5V voltage rail is unaffected and the digital part still works.

To me this feels like a time travel to my childhood, where almost every electronics project started with a 7805. exactly never are they seen in today's devices anymore, due to their low efficiency and high thermal loss.

maybe I even fried the device myself, as I plugged it to a random 9V power supply with a fitting barrel jack I found. but it was AC, not DC...

@vampiress

Yup. That bit makes me almost as misty-eyed as #HACF ... 😢

My first exposure to #RISC was in the #Alesis digital reverbs like the #MIDIverb and #Microverb. Suddenly, thanks to RISC, ordinary musicians like me could afford something as iteratively elephantine as a #DigitalReverb.

It was shocking.