ARP Soloist meets 3D Printing

This is a ARP Soloisist Slider Fixrare original ARP Soloist (before the ProSoloist or DGX). A lot or restoration work was done on it, but one issue remained; the slider shafts were all broken at the point where they exited the case, and the slider caps were long gone.

The sliders are the same type as fitted to the ARP 2600 and moog SonicSix, amongst others. This is a hard to find part, and here we have 4 sliders with 3 different values. ARP Soloisist Slider FixSometimes you can find replacement shafts for these on Ebay, but nothing was listed at this time. After much head scratching I decidedARP Soloisist Slider Fix to raise the existing sliders by 8mm, and needed some precise flat blocks to do that with. I came up with a design and after many attempts (that’s 3D printing for you!) I produced a nicely printed set.

ARP Soloisist Slider FixThe sliders were removed, opened, cleaned, re-greased, then set on the blocks which I had super-glued to the ARP Soloisist Slider Fixcircuit board. There were locators in the blocks for the original slider mounting, so when the wiring was added using a heavy gauge wire extension, all was firm and true. I re-assembled the unit and added some Omni-2 style slider caps I had previously printed. All working and crackle free. Next move was to tune and scale it.

One item remains on the Soloist, the after-touch used conductive foam which was known to only last 8 months, and had all by disappeared on this 1975 keyboard. I would have liked to have got some modern strain/pressure sensors and tried to make a solution, but the owner decided to defer that to another time.