no output from power amp?

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Mr. G., Oct 13, 2004.


  1. Mr. G.

    Mr. G. Member

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    My Peavey Classic 50/50 tube power amp finally came in Saturday. I put in some new JJ tubes as soon as I got it and had band practice that night, and it worked flawlessly. Until I tried to set it up different. I did have it running stereo, but then tried to run it mono, and no sound would come out o fit. Everything turns on fine (I haven't opened it back up yet, but even then I wouldn't know what to look for), I just don't get any sound. I ended up having to use my classic 50 combo amp for my power amp for last nights practice. Any idea's why it's not sending a signal/power to my speakers?
     
  2. John Phillips

    John Phillips Member

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    Does it still work if you go back to stereo, or has it blown something? (Possibly an internal fuse)

    How does it switch to mono?
     
  3. Mr. G.

    Mr. G. Member

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    I just happend to think about the fuses after I wrote my initial post. So, when I got home from work, I opened it up and sure enough, a fuse was blown. I'm guessing it that it hadn't been played in a good while and still has all the original fuses, and after running it for 5-6 hours fairly hard, it was just too much. I'm going to replace all the fuses tonight when I get home, so hopefully that will solve everything. I don't have anyway to play through it until Saturday though :( , because my cab is at my drummers house, and he wont be there today or tomorrow:rolleyes: .

    " How does it switch to mono?"

    it has a switch on the back to go from stereo to mono. then a switch to select the desired ohm's
     
  4. John Phillips

    John Phillips Member

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    Did the blown fuse look like it had a little break in the wire? If so, probably just an old fuse. Try a new one and see what happens.

    Or like a little firework had gone off inside? If so, something worse - and not much point in trying a new fuse until you've done a little more investigation... probably a blown power tube, but if the amp hasn't been used for a long time, it could possibly be a filter cap.

    I just asked about switching in case you had bridged the outputs without switching it correctly to mono; but you obviously know what you're doing so disregard that... :)
     
  5. Mr. G.

    Mr. G. Member

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    I couldn't tell the fuse was blown untill I took it out. It had about an 1/8" gap between the fillament. the glass is still just as clear as a new one.
     
  6. Mr. G.

    Mr. G. Member

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    I replaced all the fuses, and it worked fine...for a while. I put it on standby for a while, and when I cut it back on, there was no sound. I checked all the fuses, but none were blown. What on earth could be wrong with this amp:mad: Oh yeah, and when I first cut it on, none of the LED lights came on, but the amp was running and sounded awsome...until it died.
     
  7. Mr. G.

    Mr. G. Member

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    I don't know if this will help give a clue or not, but whenever I put it on standby, I could play my guitar with the volume up you can still hear a signal going through.

    I hope all it is, is a loose connection, but with my luck, it's probalby something worse. I'm going to try to get it to a tech sometime soon, since this is getting over my head. Thanks for all your help.
     
  8. Mr. G.

    Mr. G. Member

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    I just got word from the repair shop that the OT is gone, and they can't find another one to replace it :confused: !! I find that hard to believe:mad: What should I do? Should I keep worrying with it, or sell it for whatever I can get for it, or just throw it in the closet? I'm sick of all this crap! I'm going to look for a new head next week.....heck, maybe even another XXX. I still kick myself in the rump for selling the one I had :rolleyes:
     

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