Pignose guitar amplifier

Cheap little battery powered amplifier.
Sound OK to me.

Sounds like oxidized contacts.
If volume is a turn-knob, then wiper-track (inside potentiometer) is worn.
If it's a PTM (push-to-make) standard button, the button contacts may be dusty/dirty/oxidized.
Suggest you:
buy a contact cleaner such as Servisol,
open case,
identify controls
and squirt liberally to wash out any gunk.
Move/press/wiggle scratchy one to help 'scrub' the contacts clean.
If this doesn't help try have control replaced.

You need to clean the pot and all connectors with DeOxit 5 cleaner/

If it ocours only when turning your volume pot then the pot is worn or dirty inside. I f you are handy get a new pot that is EXACTLY the same and replace it It is simple if you can solder as there is usually only tree connections

It's probably dust in the volume control. It gets in between the carbon track and the wiper that rotates on the track, or the resistive / carbon track inside the control is wearing out. As yours is stereo there will be 2 tracks and 2 wipers, one could be worn more than the other.
This should give you an idea. Inside Pot

All you need to confirm is to remove the connection to the guitar, remove the jack and cord to the guitar and now check if the noise is prevalent at higher volume, when the volume control is turned up. If so the fault is with the cord , the jack or the gutiar pick up insulation or internal connection or shielding.
Cross check with a seperate cord or another amplifier to confirm the case.
If the noise is from within the amplifier then it is possible there is fault in the preamplifier, fault with shielding of the inputs or the preamp, broken groung connection.
Compliments of the Season.

If the volume pot is scratchy noisy, FIRST try squirting a bit of CRC226 into the pot. CRC226 is available at Home Depot in the electrical department. There are other CRC products there so be sure to get the 226 type. About $2.75 a can.

The product is also good to use in slide pots on mixers. Use sparingly, it doesn't take much. For rotary pots you often can use the spout to spray into the slot where the terminals go into the pot.

Either the control is damaged (happens if they get hit) or it is possible the circuit board it is mounted on has broken solder OR worse, a crack near the control. The unit will require servicing. Parts are readily available.

That is a common symptom of not properly grounding of negative side of the output of power amplifier section.Just resolder all component parts joint in power amp.sectiton and double the solder all negative ground.Also clean the pots of all volume controls and selector with a lighter fluid or desame that fluid so whatever sound or crackling noise eliminated and works normal again.. Hope it may help you;;

You have dirty potentiometer (pot) controls. Unfortunately to clean them properly you will have to remove the amplifier from the wooden cabinet. If you're not comfortable doing this then send it to a local musical instrument/amp repair shop.

1) Disconnect AC power (duh)
2) After carefully documenting all connections, unplug/disconnect speaker, footswitch and the reverb wires on the back of the amplifier.
3) Look for four screws along top of wood cabinet that hold the inverted amplifier in place (thank you Leo Fender). Normally there is a wood block that will prevent the amplifier chassis from dropping down as the four screws are removed BUT assume nothing.
4) When amplifier is completely free from the cabinet top, carefully slide it out the backside.
5) Up on the bench avoid the filter capacitors (look like a C size battery) in the amplifier chassis located over by the AC power cord as they may still hold an electrical charge.
6) Look for the three terminals exiting each pot along the front of the amplifier chassis. Using a PLASTIC SAFE tuner/control cleaner/lube (Radio Shack Model 64-4315/Catalog #64-4315) aim the extension nozzle into the open area where the three terminals enter the pot.
7) Turn the pot knob CW/CCW while dispensing a small amount of.the control cleaner. Repeat with all controls.
8) Re-assemble (don't forget to reconnect all the wiring from step #2) and download a couple of new guitar TAB's for proper testing inspiration.....Glen :-)