EHX 45000 Fader Replacement

Loop Pedal Repair

The EHX 45000 was Electro-Harmonix’s flagship looping pedal for a number of years. It has 4 adjustable tracks, can do stereo input, some midi control, and even has some mix down features. It’s a cool pedal! However, living in Ireland meant that after a few years in storage mine was affected by damp. The faders which are used to control the track levels rusted and developed mechanical and electrical faults, rendering the pedal much less usable than it had been. I decided to try to try to fix this, but ran into a few issues along the way, so I hope that the info here might help future fixers.

Taking the pedal apart is easy enough, only basic tools required, and the faders and where they attach is obvious once the board is exposed. However, this reveals the first issue. What do I replace them with?

What faders should I buy?

There is a big variety of faders available, and most of them are not going to fit here. There is a really big variation in where mounting posts are placed, how long the faders are, and the resistance they themselves use. I used these from Mouser, you may be able to source similarly designs in other places, but for an order to Ireland these seemed to make the most sense. EHX did respond to an email on this, but they pointed me to Small Bear Electronics, whose shipping costs were prohibitive (and it wasn’t an exact match). Those faders can be found here though. If you’re searching elsewhere I would recommend comparing with the data sheet for the Bourns pots linked, the part number of which begins with PTA3043.

Once those had arrived, I excitedly screwed everything apart again, and began trying to desolder the old faders. This was a mistake.

The faders won’t come off!

Faders, due to their large size and subsequent large thermal mass, require a lot of heat to bring the solder to melting point for removal. My little soldering iron just could not provide the heat! I was worrying about damaging the board from the contact time before I got anywhere with the solder. On top of that, a single point was taking me minutes of work. It was simply not going to work. I looked into higher wattage soldering irons, as well as different tips, but these solutions were no help. If you have a large, temperature controlled iron, you may be able to desolder here (and you probably know more than me), however if you do not, I would highly recommend you purchase a desoldering gun.

I cannot recommend this desoldering gun from AliExpress enough. It gets incredibly hot, and the vacuum action is really powerful. It transformed the desoldering part of this work from something I was dreading into a quick and fun job. Check out the video for just how speedily it works!