Toasted my Marshall

[Ray 911S]

A short in my footswitch cable caused an overload somewhere inside my Marshall 9001 tube preamp. The power still comes on and the tubes still glow, but no noise or switching. Options appear to be: write it off as a lost cause and start looking for another tube preamp, or try to find a qualified repair shop.

Anyone know of a possible repair center that I could send this to?

If I have to buy another, what 1U tube preamp do you recommend?

 

[Jeff_H]

Re: Toasted my Marshall

I would bet that a fuse or something else fairly simple is fried. Most amps have some safety features to prevent total failure. As for techs, I'm not famalier with Chicago. I would bet there are many, many qualified techs there. If you want to ship it off to one of the best, send it to Trace @ Voodo Amps. He can do anything to one.

 

[wixedmords]

Re: Toasted my Marshall

Same thing happened to me today Ray.

I have a new-to-me AOR 50 head. I had an issue today with no sound coming out. It had glowing power tubes, a glowing P1 pre tube and I swapped out cabs with my other amp head. I was also able to get a bias reading with my meter, and I checked the wiring for any burned issues. I was just heading off to buy new fuses when I realized I should swap out the rectifier tube.

Swapped the tube, and it began to glow.

I have a website I refer to when the "no sound" issue comes up.

Here is is:

http://www.geofex.com/ampdbug/nosound.htm

 

[Ray 911S]

Re: Toasted my Marshall

Well, hoping that you are right and there is a simple fix, I downloaded a copy of the schematic diagram. Incredibly, there is 15 volts in the footswitch. The failure happened when the EQ switch was pressed - so I know that the short fed somewhere between 15 and 22 volts back up into the preamp. The mainpower went off for a second, then back on. No real hints or clues in teh wiring diagram, and the only fuse is on the mains.

After that rookie analysis I am out of my depth. Thanks for the reference - I'll contact Voodoo and see if they're interested in looking at it. So sad - man I really loved that preamp!