Waldorf Blofeld Encoder Fix

Waldorf Blofeld is amazing little digital synth with almost endless possibilities. Unfortunately the rotary encoders seem to start skipping and failing sooner or later. After couple of years of light use my unit started failing too and it became very annoying to use. 

First Try

I first tried to open one encoder and clean it from inside. It worked ok but these components aren't really meant to be opened and closed again and I never managed to put it back together properly. Encoder shaft was loose and wobbly and it would have failed again soon because the encoder wasn't tightly closed.

Proper Fix

Luckily it's possible to fix it properly as long as you know how to solder. Current price for the full set of encoders is less than 7 euros.

I ordered new Bourns encoders from Mouser:

• 1 pcs of https://www.mouser.fi/ProductDetail/652-PEC16-4220FN0024 for the main encoder, this one has detents so it "clicks" when you turn it.
• 6 pcs of https://www.mouser.fi/ProductDetail/652-PEC16-4020FN0024 for the others. These don't have detents so they rotate smoothly.

First step is to remove all knobs. Just pull directly upwards and they'll come off.

Bottom half of the enclosure can be removed after removing the screws.

Power switch and power connector are a bit tricky but you can access encoders by carefully lifting the PCB.

Then comes the hardest part. Be extra careful when removing old encoders as the PCB traces get easily damaged. Probably the easiest method is to cut the legs, remove the encoder and then clean the soldering pads one by one with a soldering iron and solder wick.

Cleaning the pads after broken encoder is cut off.

Fresh new encoders from Mouser. These are trivial to solder as long as the pcb was properly cleaned in previous step.

Done! Works better than ever!

I also replaced the original slippery metal knobs with more functional plastic ones. Feels like I can control the synth more accurately now. I think it also looks better with these classic style knobs.