The BOSS OS-2 is a pedal designed to give the player a combined set of SD-1 and DS-1 tones in a single robust box. I managed to buy this one reasonably locally on the basis that the ‘Color’ and ‘Drive’ controls had snapped shafts. Whilst made in Taiwan, this one was still slightly older than the current generation one – consequently, it used potentiometers that had 16mm metal backshells and 5mm pin spacing, but the tapers and values aren’t as commonly available as others.
There aren’t an abudance of authorised Roland/BOSS parts dealers around, but I was able to contact the nearest authorised repair specialist.
They were extremely kind in being able to provide the official schematic for the parts (not that I needed it in this example, as the potentiometer resistance values and tapers were marked on the remaining parts), but more importantly, they were also able to order the parts on behalf of me, from BOSS in Japan.
Parts arrived a few weeks later, at £20 for the pair of potentiometers all-in.
But there was a problem…
…They had supplied the potentiometers for the more modern version of the pedal – I’m assuming due to the original sized potentiometers now being obsolete.
As the shaft size, type and threaded area was correct for the pedal, I pretty much had to go with these. So I had to use solid core hookup wire, cut it down to approximately an inch and a half in length, use forceps to bend small loops at the end and then solder it to the legs of the potentiometers.
The two main challenges I faced were 1) Leg spacing and 2) Heat transfer. The former to avoid accidentally soldering legs together, given the added space occupied by the looped wire and the latter to avoid melting the internals of the plastic boded potentiometer. I was using a conventionally sized soldering iron with a conventionally sized tip, which in hindsight, added to the challenge.
It wasn’t pretty, but it worked.
Putting it all back together, I now had my OS-2 work “good as new”.
Of Sound Mind 