Is a Power attenuation toggle switch stock on RM50 Combo?

[Ricey]

Well, the amp blew and I did not even try try using the switch yet, other than to briefly listen to compare the fan speed in both positions. I am going to post a new topic on the blow out.

 

[Jaded Faith]

See my post in your other thread. This needs to go to a shop.

 

[Ricey]

Dropped amp off at the shop today. The tech said the switch appears to be wired to a transformer. He is going to check it out and will disconnect it if he thinks it is sketchy.

 

[kc2eeb]

It would be helpful if your tech specifically describes what the connection(s) are and what he specifically did to repair the amp. Even if you do not understand right now what he may say, it will be useful in the future.

 

[Ricey]

Agreed, I will post as soon as I get his diagnosis. He is about the only guy left in my area doing amp repair and he has all of the warranty repair contracts for the major amp manufacturers, as well handling all of Guitar Center's repairs. Needless to say, he is very backed up and said it will probably be three weeks before he gets to it.

 

[Ricey]

The Tech said that someone wired up a second lower powered transfomer, complete with a bias trim pot. The transformer is screwed in to the inside of the speaker cabinet. This second bias pot is internal, so I can't get to it without taking the amp apart, so next time I change power tubes, I will have to take the amp back into the shop if I want to use the power attenuation switch. He said the guy who did it really seemed to know what he was doing and that he would have no issue using the switch himself.

 

[kc2eeb]

Wow! That's very interesting and thanks for the reply. If you would know, for that to work, it would require separate high voltage and bias connections (i.e. wires) to the chassis as well as an AC power connection to the transformer. Is that what was done?
I always thought that an RM50 with around 325-350 volts on the plates and 2 6V6s would be one of the sweetest amps ever.