WD40 is nasty stuff. it gums up things. I won’t even let it near my bikes. there are better contact cleaners to use, you can buy a can from cpc.farnell.com and other similar places.

its been a long time since I did any mixing, but what I find more annoying is that often the actual fader itself costs 2 quid, and if you can get the component it could be soldered on to the PCB but it is near impossible (in England at least) to find them in electronics places at the right dimensions and resistance level :rant:

I used to repair sound mixers and other kit for the BBC, Anglia TV and other such places and they always used components you could buy from Farnell or Canford…

its a complete ripoff TBH. this is the actual bit inside your average mixer.

Stereo Dual Slider Potentiometer Peavey Stereo Dual Slider Potentiometer 10K 60mm 31191064 – Stagebeat – 10K 60mm 31191064

about 15(!!) years ago mixers didn’t have replaceable crossfaders, but as most pots were the same dimensions it was easy enough to mount another one in there..

I can’t remember though whether a crossfader uses a linear or log pattern. I think its linear or the centre point would be in the wrong place… cheesweasel would probably know for sure.,,

from wikipedia..

Linear taper potentiometer

A linear taper potentiometer has a resistive element of constant cross-section, resulting in a device where the resistance between the contact (wiper) and one end terminal is proportional to the distance between them. Linear taper describes the electrical characteristic of the device, not the geometry of the resistive element. Linear taper potentiometers are used when an approximately proportional relation is desired between shaft rotation and the division ratio of the potentiometer; for example, controls used for adjusting the centering of (an analog) cathode-ray oscilloscope.

Logarithmic potentiometer

A logarithmic taper potentiometer has a resistive element that either ‘tapers’ in from one end to the other, or is made from a material whose resistivity varies from one end to the other. This results in a device where output voltage is a logarithmic function of the mechanical angle of the potentiometer.

Most (cheaper) “log” potentiometers are actually not logarithmic, but use two regions of different resistance (but constant resistivity) to approximate a logarithmic law. A logarithmic potentiometer can also be simulated (not very accurately) with a linear one and an external resistor. True logarithmic potentiometers are significantly more expensive.

Logarithmic taper potentiometers are often used in connection with audio amplifiers as human perception of audio volume is logarithmic

so its probably a linear used in the crossfader but log ones everywhere else in the mixer (its been a very long time since I replaced one..)

Some crossfaders dip in the middle (I dunno the tech behind it tho) so as to not get a audio boost from haveing two signles … some have a variable curve knob (called a hampster or squirel switch? – my mate allways takes the piss cos I allways get the wrong animal and that name might just be for the reverse input feature for scratching.) but most decent moden crosfaders (unless tech’s moved on even more since i last checked) are led/laser ones. Alltho they are not useualy standard in mid-range priced mixers afaik (you have to upgrade yourself). Only top spec ones have them as standard as they can be pretty expensive on there own.

You’ve got led’s one side and sensors the other like this:-

………..

with something blocking them where the cross fader is :-

……I…

It’s basicaly a digital version. 1/0

The very top range are magnetic floating zero contact ones so not even the rail that holds the fader inplace can get stiff because of rust (aparently they tested how good one actualy was by pooring coke over it and it still worked perfectly even after it dried!) They are pretty much invinsible.