©2019 by IronAgeAudioworks

replacing slide potentiometers (faders)

The faders on the 1280 console are one of its most fragile electro/mechanical components, considering the amount of use they get and the fact that the potentiometer body has an open slot that invites all sorts of dust and moisture.

You can see pictures of the condition of some corroded faders and the wear and tear they accumulate with time here. "Cleaning Faders"

The faders installed in the 1280 are:

Manufacture: ALPS (Japan)

Part No: 79G-10kΩA

Resistance: 10kohms

Taper: Audio

Dimensions:

I could not find anything within the catalog of the most popular manufacturers that would exactly fit.
The travel distance of 60mm is a format that apparently is not used often on a large console format, it may be used on smaller equipment so it is difficult to find variety through the usual distributors.

ALPS does have a part with the same travel, resistance and taper, but it does not have the same lever type.

Matt found a potentiometer in the Bournes catalog that fit all the specs with the exception of the distance between bolt holes as you can see below.

You can order this part from mouser.com for only a couple of bucks.

Comparing them side by side, your notice how the new fader is smaller than the original installed part.

Since the Bourns fader is also only available with pins for PCB mounting, I decided to make a PCB that would hold the fader in place and also be large enough to accomodate for the original footprint.

The PCB does a really nice job of holding the fader in place and it can be easily installed in the console.

The new faders have the same function as the original ones.
Since the new body and components are smaller than the original ALPS, you will see that the slot on the top of the fader is shorter than the original, yet the fader has the same amount of travel.

Please watch the video at the top of the page, there are more details there.

Please contact us with any questions.