6L6 makes crackling noise

[johnnyguitar]

My Twin Reverb starts making a crackling noise..when I push on one of the tubes it stops for a while until I start playing again..it feels loose in the socket too..bad socket??? If so where might one get such a beast...thanks in advance

[Old Tele man]

...first, try spraying the socket with 'contact cleaner,' but this won't help if the contacts have "spread."

...typically the socket contact "fingers" eventually spread over the years, resulting in 'intermittant' contact, especially when playing.

...two options: (1) replace the socket, or (2) re-tension the contacts.

[John Phillips]

A common cause of this on Fender amps is a cracked grid-stopper resistor - the small 1.5K-ohm one between pins 1 and 5. If you wiggle the tube while looking at it you might even see the crack. They fail with heat and vibration over the years. If one has gone, it's best to replace them all - use metal-film ones not the original carbon-comp type which are prone to heat failure.

While you're at it, replace the carbon-comp screen-grid resistors (the large 470-ohm ones, you'll find it easier to replace the grid-stoppers if they're out of the way anyhow) with 2 or 3W wirewound types, for the same reason - wirewounds are much more stable and reliable under heat stress and particularly under overload, eg if a tube blows.

Neither of these upgrades affects the tone BTW.

[johnnyguitar]

Originally posted by John Phillips
A common cause of this on Fender amps is a cracked grid-stopper resistor - the small 1.5K-ohm one between pins 1 and 5. If you wiggle the tube while looking at it you might even see the crack. They fail with heat and vibration over the years. If one has gone, it's best to replace them all - use metal-film ones not the original carbon-comp type which are prone to heat failure.

While you're at it, replace the carbon-comp screen-grid resistors (the large 470-ohm ones, you'll find it easier to replace the grid-stoppers if they're out of the way anyhow) with 2 or 3W wirewound types, for the same reason - wirewounds are much more stable and reliable under heat stress and particularly under overload, eg if a tube blows.

Neither of these upgrades affects the tone BTW.

Is there a wattage requirement for the 1.5K grid stopper resistors??? thanks again