SEQUENTIAL CIRCUITS

PRO ONE

This synth is one that I have always wanted. being a fan of Yazoo I always loved the crisp electronic sound of this powerful mono synth. I saw one on eBay that needed a bit of work. The tuning was all over the place and one key was broken, but it seemed functionally ok.

I replaced the DAC chip and all the electrolytic capacitors. I then did a tune up. Some of the pots were scratchy so a quick blast of switch cleaner and they were much better. One of the wooden side panels was damaged so I just rounded off the broken corner. A bit of a sand down and some wood stain and they looked proper job. I got some new knob caps to spruce up the front panel. They was a cigarette burn near the bend wheel but hey it's a bit rock'n'roll.

Once I had the synth working, I decided to upgrade it to the Turbo CPU. This replaces the current CPU with an upgraded PCB. This allows MIDI and other functions. Be sure you know exactly how to fit this before you start as the CPU designer will just tell you to basically RTFM if you ask any questions.

 

PCB out for a service

pcb

 

Old CPU and DAC

 

Here's the new turbo CPU and MIDI board, with IN/OUT

cpu

 

MIDI install

midi

midi install

 

replaced tantalum capacitors in power supply

tant

e;

 

refurbished wood side panels

p

 

Ubiquitous Mandala shot