Discussion in 'Amps and Cabs' started by gtrplr71, Feb 20, 2015.
my Princeton has some scratchy pots that I need to clean is it easy to do? please explain.
On a 1-10 scale it's about a 2.
Remove chassis(don't poke around inside)
Find pots at the front of the amp
Use a lubricated cleaner Caig Deoixt is the standard
Spray a small amount in the opening under the solder tabs
Rotate(the pot that is).
that is what I have is deoxit. thank you
Before you remove the chassis, try the easy way. Remove the knobs. Spray deoxit cleaner/lubricant around the base of the post. Twist post back and forth full range about 10 times. Move on to the next one.
My SFDR had a bunch of scratchy pots and this method worked brilliantly with much less effort than removing the chassis.
Sometimes just turning the pot back and forth 10 times will clean it. I normally just remove the chassis and do it like Soldersucker said though.
If you've never pulled a chassis before be very careful of the face plate they bend real easy. And of course there's the shock hazards inside even in an unplugged amplifier to watch out for.
That is really not very effective, it will clean & lube the shaft & bearing surface really good though.
The BEST access on most pots is via chassis access, you need to get to the wiper & carbon element surfaces with the cleaner.
The carbon area faces the REAR of the pot hence not much cleaner if any can pass along to the elements via the shaft.
That's just a good way to make a mess. I'd venture a guess that you turning the pot 10 times did more than deoxit.
Not likely the Deoxit made it to the area needed!
Soaking the pot doesn't seem to be a permanent solution.
Not sure there is one.
This is the "best" method possible
While doing this, one can also slightly bend the wipers so they're contacting virgin material.
Another option -- You can buy brand new CTS pots, gut them, and replace the inner PCB/carbon strip & wiper. The design hasn't changed in 40 years. You basically have a brand new pot then, with the original post.
I don't recommend dis-assembly unless the pot is really really bad. Usually just a couple light shots with cleaner/lube is all they need.
I love the CTS pot design, You can take those old fender CTS 10K bias pots apart and replace the element and make them into 25K or 50K to improve range.
Been doing that for years.
Don't use the standard deoxit for pots. That stuff is meant for non-moving contact points. Use the "Fader" lube (FN5, I think), also from Caig.
I have some peavey funk out cleaner for pots I did remove the chassis but the pots are covered by green solder board.
Deoxit also dissolves the greases inside the pot. It's over-cleaning. There's some very "special" grease in there that is not replaced with deoxit or any other spray can.
If I were an amp tech, doing this for a living, sure I'd squirt some sh*t it there, and it'd be "fixed" long enough that I'd collect $$$ and be on to the next job. It's a band-aid, not a fix.
Besides, it doesn't do anything for a worn out track except delay the inevitable (replacement).
IMHO of course
Just reiterating what a couple others have said here, but it bears repeating. First try simply flipping the knob back and forth a bunch of times. A very small amount of oxidation can make a lot of noise and a little mechanical movement can correct most of that. Do NOT spray Deox-it into the shaft/bushing area. It will not only dissolve the lubrication in there that makes the rotation feel smooth, but none of it will get to the wafer surface. Deox-it is a lubricant and it's messy. If after flipping the pots you still have a noisy one you can use Deox-it since you have it but SPARINGLY. Before you drench the pot and surrounding electronics, practice pressing the sprayer button so lightly that only one small drop comes out. That's more than enough to clean a pot track.
I keep reading about cleaning a pot being a Band-Aid type thing. I've got amps I've had for 15 or more years some had noisy pots when I got them a shot of cleaner fixed them all.
That said I don't use Deoxit been using Radio Shack tuner cleaner for years. Maybe it's the same or maybe it's better? IDK but it works for me.
That said if a pots bad cleaning won't help right from the get go. And never forget there are other causes for noisy pots like DC on them.
its not that bad minor really but just enough to make my OCD kick in
Another overlooked item;
Dirt/crap, dust & oxidized particles can build up on the wiper especially if it has excess lube sprayed into it.
If you get a can of decent keyboard spray(compressed gas) a couple shots to blow it out can do a lot to eliminate noise.
When & if I use cleaner/lube I always wrap as much of the pot as possible with paper towel to catch any mist or over spray.
Wrap that sucker
Go have a ball
thanks that's a good idea.