Rusty pots

[thop]

I decided I'm going to sell my old valvestate and go all tube. I got a great deal ($150 is a great deal right?) on an old peavey classic 50 2x12. Sounds awesome, but theres a lot of rust and the gain pots were super crackley.

 

I opened one and found this. Is it worth cleaning? For a guitar I'd just buy a new pot but can I even buy generic pots for this or do I need to contact peavey. My preliminary google search seemed to imply that I'd need to go to peavey.

 

 

 

[WRGKMC]

I'd clean them first with lubricating pot cleaner.

Chances are they are fine and have just been neglected and are oxidized and dirty inside.

They may last you another 10 years and having the original pots retains the value.

 

Mild exterior rust is common and not that big a deal.

You can use a scotch brite pad to get rid of the bulk of loose rust.

Use a vacuume at the same time to suck up any grit.

I'd arrest the rust using some WD40.

 

You can saturate and old paint brush and wipe it on the

chassis, transformer extreiors etc and then use a soft rag to remove andy excess

rust particles. Be careful not to contaminate any electrical connections of course.

 

Be sure to clean the tube sockets, and make sure its dry before powering it up.

Check the power caps for buldges or leaking on the + ends. If in doubt, change them out.

power caps are only $4~5 each and can save hundreds of dollars of damage blowing transformers when they blow.

New power tubes are only $20~$40 for a matched pair. Something like JJ's will handel power overages and sound killer in those amps.

[philbo]

Judging from the amount of corrosion on the wiper, I'd say replace 'em.

 

You need 3 pieces of info to find new ones:

1) The total ohms (between the 2 outside terminals), which can be measured easily with a DMM ($20 or so at Radio Shack)

2) The type of taper. This is tougher. One way to do it is to move the knob in equal increments (as best as you can manage) and see if the Ohms from the center terminal to one of the outside terminals changes equally across the both ends of the rotation range. If it either A) jumps quickly, then slows down, or B) changes slowly, then abruptly toward the end, you need a pot with a 'log taper'. If it changes equally over the rotation range, you need a pot with a 'linear taper'.

3) The diameter & length of the knob shaft.

 

You should be able to find some at mouser.com

[Belva]

The last pic looks like a 10K pot, but I can't see it that clearly. Maybe one of the people here with more experience that I can tell you exactly what you need by copying the letters and numbers on the back of the pot/s and posting them here.