Help!!!

[PilotSSW]

I was playing my lonestar tonight and the drive channel started cutting out. So I figured oh, maybe, its a bad power tube, but I switched on the clean channel and its fine. Puzzled, I pulled the instrument cable and the drive channel is fine. But then I go to adjust it, as the sound is now somewhat woofy and scratchy. The gain knob turned up actually turns the volume down and the treble knob made the signal go in and out. The Bass and middle do the same too. Once again the clean channel is fine and it seems as if the power tubes are fine. I have done the reeder mods, but everything to be soldered sturdily. Before I go fooling around the inside of the amp, does anyone have any suggestions ?

~ Sean

 

[Charles Reeder]

If...the mods were done correctly then the likely culprit is a bad pre-amp tube. ( #1, #2, or #3). Check them by swapping out.
An incorrectly done mod; or one where a 'stray whisper' of braided wire intermittantly grounds out against another contact could cause the symptoms you are experiencing.

Try tubes first as it is the easiest. If that doesn't solve the problem...then prepare to give the 'mods' a really close look.

Charles

 

[plan-x]

I have never heard of things like this....especially the inverse gain. :? Sounds like some crossed wiring. And shaving cream in your pots. :shock:

 

[PilotSSW]

It was indeed a bad pot. I believe some solder may have fallen in during the reeder mod and I just didn't notice and it didn't cause a problem until now. Anyhow I removed the pot and blew it clean with some electrical contact cleaner and it viola, it's as good as new.

 

[Vogelsong]

It was indeed a bad pot. I believe some solder may have fallen in during the reeder mod and I just didn't notice and it didn't cause a problem until now. Anyhow I removed the pot and blew it clean with some electrical contact cleaner and it viola, it's as good as new.

:shock: shew, that was a close one. Symptoms like that make me cringe.

 

[PilotSSW]

shew, that was a close one. Symptoms like that make me cringe.

No kidding I freaked a bit when it happened. My first thought was "ok here we go, how much am I gonna have to spend this time" bahahaha !!!

~ Sean