Seymour Duncan convertible 100 watt tube glows bright.

[DanW]

Seymour Duncan convertible 100 watt tube glows bright This unit has distorted output and one tube glows brighter that the other output tubes. I am suspecting the big filter caps bad, can anyone provide schematic or tell me what the voltage is on C12 & C13 200mfd/350volt caps???

 

[muttonchopsrule]

Re: Seymour Duncan convertible 100 watt tube glows bright.

what makes you think its the filter caps? it's probably just the tubes that need replacing.

 

[ErikH]

Re: Seymour Duncan convertible 100 watt tube glows bright.

Could be more than the tubes needing to be replaced. It is severly mis-biased if one is glowing brighter than the other. It may also be the output transformer on its way out. Right before the power tranny went in my Marshall all 4 tubes glowed really bright, the plates were glowing orange heavily, and then it shut down.

Get it serviced.

 

[muttonchopsrule]

Re: Seymour Duncan convertible 100 watt tube glows bright.

Could be more than the tubes needing to be replaced. It is severly mis-biased if one is glowing brighter than the other. It may also be the output transformer on its way out. Right before the power tranny went in my Marshall all 4 tubes glowed really bright, the plates were glowing orange heavily, and then it shut down.

Get it serviced.

i don't disagree with you, but just because one tube is glowing brighter than the others doesn't necessarily mean there are other underlying problems elswhere in the amplifier's circuitry. not to mention that distorted output is one of the classic symptoms of output tube failure.

as the saying goes, 99% of problems in a tube amp are tube related. i'd start be replacing the tubes and rebiasing accordingly, and troubleshooting from there if that doesn't fix the problem.