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Post by dickieg on Feb 26, 2007 19:45:07 GMT -7
It was fine this afternoon. When I turned it on tonite - nothing. Light is on; fuses both seemed okay. What could it be. No sound at all?!!
Dickie@thegarretts.net
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Post by (8^D) on Feb 26, 2007 20:20:52 GMT -7
Check easiest thing first.
Check to make sure the speaker lead is plugged into the "speaker out" of the chassis - and that the clips are both attached to the speaker itself.
If that doesn't do it, the look to the Recitfier tube or retainer socket.
Turn the amp off. Give the Rectifier a push to make sure it's seated properly. Turn the amp on. Watch to see if the recitfier glows and the power tubes 'blue' up a bit.
If nothing, keep the amp on and lightly wiggle the Rec just a bit to see if it starts to glow at all. Sometimes the retainer clips w/in the actual ceramic socket that 'bite' the tube pins spread out a bit and lose contact with the tube - causing the power to drop, signal to fade and upon occassion die completely. Exact scenario happened within the past couple weeks with my Maz Sr.
It's usually the easiest thing...and that's either a fuse or tubes or external cables (instrument/speaker).
Hope that helps!
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Post by dickieg on Feb 26, 2007 22:56:52 GMT -7
Okay - what's the Rectifier?? (I'm not bad on guitar, but am an idiot with electronics!) Cables to speakers are fine. Let me say that the amp wasn't touched between the time it worked (beautifully) and the time it became mute. Thanks so much for taking the time. I have a few extra (NOS and expensive)tubes here. Maybe with direction I can do this myself???
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Post by hdahs143 on Feb 26, 2007 23:17:54 GMT -7
The rectifier tube is the one labeled 5AR4/GZ34 and if it's the original tube in your Maz is most likely a Sovtek.
It's job is the first component in the conversion of AC voltage to DC voltage which everything in your amp runs on with the exception of tube filament heater power, which is commonly a small AC voltage
Sounds like your rectifier tube may be the problem.
Good luck
Harold
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Post by dickieg on Feb 27, 2007 12:55:23 GMT -7
I took it to the local repair shop (he does all the warranty stuff around here). He checked the fuses - they were good. He took out the rect tube, put in another one - and it worked fine. But, when he put the original Rectifier tube back in - it still worked fine!?!?!?! - Now I'm very confused; could just moving that tube around a bit have been the issue???
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Post by (8^D) on Feb 27, 2007 13:10:21 GMT -7
I took it to the local repair shop (he does all the warranty stuff around here). He checked the fuses - they were good. He took out the rect tube, put in another one - and it worked fine. But, when he put the original Rectifier tube back in - it still worked fine!?!?!?! - Now I'm very confused; could just moving that tube around a bit have been the issue??? Yes, see my post above. "Sometimes the retainer clips w/in the actual ceramic socket that 'bite' the tube pins spread out a bit and lose contact with the tube - causing the power to drop, signal to fade and upon occassion die completely. Exact scenario happened within the past couple weeks with my Maz Sr." DW
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Post by dickieg on Feb 28, 2007 14:12:24 GMT -7
DW So what did you do? Did you have to replace the ceramic socket?
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Post by (8^D) on Feb 28, 2007 22:13:23 GMT -7
DW So what did you do? Did you have to replace the ceramic socket? I retensioned the outside retaining clips (bent them in a bit more to bite the base of the tube a bit better). Then I took a jewelers screwdriver and went around each clip inside the socket (from the side where the tube inserts) and lightly bent the mini-clips inwards again so they would make contact with the tube pin as the tube was inserted in the ceramic socket. The individual pin sockets have a 3-piece metal clip - they get 'tired' after several tube changes or if the amp gets moved a lot - vibration or wiggling of the tube. So, tightening them up/retensioning a bit improves the contact and keeps the current flowing as it should. Be gentle - the mini-clips will break and can get out of shape if you're not patient. Of course, all this was done with the amp unplugged. If you can get to the chassis w/out pulling it (i.e. flip the amp upside down) it's pretty easy. Dropping the chassis to get a better look while doing this only takes removing 4 screws. Do need to be mindful to not touch other 'things' inside the amp while you're tweaking. Long/short of it all = If you're not comfortable with this, it should be done by your tech...and only take a few minutes. Have found it a good idea as part of regular maintenance on a tube amp...check the bias and retension the socket(s).
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