another amp failure ?

[SSII x 2]

When I power up my Champion 600 RI, it runs fine for about 2-3 minutes,

then no sound except for a loud hum. Jewel lamp is lit throughout. Any

suggestions?

[tbonesullivan]

When is the last time it was in for servicing? When I have amp troubles, my first course of action is usually to clean all the contacts and potentiometers.

[SSII x 2]

I bought it new, maybe 6-7 years ago, when they were still in production,

and it's been used lightly. I will say that the trouble started when I retubed

it with great NOS tubes. Maybe I ought to change it back and see what

happens?

[mrjamiam]

I bought it new, maybe 6-7 years ago, when they were still in production,

and it's been used lightly. I will say that the trouble started when I retubed

it with great NOS tubes. Maybe I ought to change it back and see what

happens?

Yup. I would call that a "clue".

[Brewmaster]

Always check the tubes first, it's the low hanging fruit.

BTW, it has been my experience that NOS tubes in some of the newer cheaper amps don't hold up.