Hi everyone, I'm new here. I stumbled on this forum through a google search for information on an amp for sale.
My son has a Peavey amplifier, it's got six 6L6 tubes that we just replaced. Three of them are getting EXTREMELY hot and three are barely lighting up. The preamp is solid state so there are no pre-amp tubes. This thing is getting so hot I'm afraid the cabinet is going to catch on fire.
Any suggestions? (Please, don't get too technical. What you are dealing with here is the mom of an 18-year-old guitar player and neither of us are very tech savvy).
My son has a Peavey amplifier, it's got six 6L6 tubes that we just replaced. Three of them are getting EXTREMELY hot and three are barely lighting up. The preamp is solid state so there are no pre-amp tubes. This thing is getting so hot I'm afraid the cabinet is going to catch on fire.
Any suggestions? (Please, don't get too technical. What you are dealing with here is the mom of an 18-year-old guitar player and neither of us are very tech savvy).
By lighting up, do you mean that the plates (the outermost metal part of the tube that you can see within the glass) are starting to glow, or that the filaments (smaller, visible from the top of the tube, and near the center)?
The filaments are supposed to glow, and should be an orange color. The plates should not. Horribly incorrect bias could potentially cause the plates to overheat and glow, some other internal amp failure could also cause it.
What is the model number of the amplifier? This would help folks to offer further suggestions as to the possible problems.
-Pat
The filaments are supposed to glow, and should be an orange color. The plates should not. Horribly incorrect bias could potentially cause the plates to overheat and glow, some other internal amp failure could also cause it.
What is the model number of the amplifier? This would help folks to offer further suggestions as to the possible problems.
-Pat
1) This is in the wrong forum
2) Need more details to help you. What is the amp model? Did the problem first start after you replaced the tubes, i.e. everything worked fine before then? Exactly what tubes did you replace?
There is a known problem of replacing true 6L6GC tubes with relabeled 6P3S tubes causing serious problems. 6L6GC is good for 500V on the plate and 30W dissipation, but 6P3S cannot handle that much voltage and is on about 20-21W dissipation.
2) Need more details to help you. What is the amp model? Did the problem first start after you replaced the tubes, i.e. everything worked fine before then? Exactly what tubes did you replace?
There is a known problem of replacing true 6L6GC tubes with relabeled 6P3S tubes causing serious problems. 6L6GC is good for 500V on the plate and 30W dissipation, but 6P3S cannot handle that much voltage and is on about 20-21W dissipation.
The best advice I can give you is to get it to someone who has at least some experience with tube amps. Tube amps deal with (very) high lethal voltages. To find out what's happening there's probably some basic voltage measuring required and that should not be done by someone inexperienced.
Hi,
For sure something is wrong.
I have no suggestions - it needs looking at by someone
who knows their stuff. FWIW by your account simply
don't use it, you may burn out 3 of the valves quickly.
rgds, sreten.
Could be lots of things in a failure sense, or just simply
misadjustment. Model and service manual would help.
For sure something is wrong.
I have no suggestions - it needs looking at by someone
who knows their stuff. FWIW by your account simply
don't use it, you may burn out 3 of the valves quickly.
rgds, sreten.
Could be lots of things in a failure sense, or just simply
misadjustment. Model and service manual would help.
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We need the model name. It sounds like a Mace. The amp Lynyrd Skynyrd made famous. PV also made the Roadmaster with six 6L6s but that was an all tube version. The Roadmaster with the solid state preamp only had four power tubes. SO I am betting on the Mace.
The schematics are freely available, and Peavey customer service will send you any you request.
The original Mace is now referred to as the A series had adjustable bias, and maybe you simply need to adjust that. The B series was similar. They had all transistor preamps. Then came the Mace VT series which used op amp ICs instead of transistors. There is no bias adjust on the VT version, the stock setting is fairly cool and should not cause issues.
As someone asked above, are you seeing the heater in the center of the tube glowing? Or are you seeing the metal structures inside the tube getting red hot?
The schematics are freely available, and Peavey customer service will send you any you request.
The original Mace is now referred to as the A series had adjustable bias, and maybe you simply need to adjust that. The B series was similar. They had all transistor preamps. Then came the Mace VT series which used op amp ICs instead of transistors. There is no bias adjust on the VT version, the stock setting is fairly cool and should not cause issues.
As someone asked above, are you seeing the heater in the center of the tube glowing? Or are you seeing the metal structures inside the tube getting red hot?
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