Classic 50 volume reduction

[proaudioguy]

A friend in another state has a classic 50.  Its too loud.  I do not see an adjustable bias.  He is not competent to be inside the amp.  When pulling 2 tubes on a twin and disconnecting 2 speaker, I have always rebiased but I
Never noticed if I needed more negative voltage or less.  I’d like to tell him to pull 2 el84s, and disconnect one short one speaker.  My question is if he would be in danger of too hot a bias (too low neg voltage).


What do you all think?

[shooter]

I wouldn't recommend it, time/money better spent finding someone that can do the work, especially some 'ol guy that's just in it to keep his skills sharp.
Those amps are already problematic, tend to flame-out just because they can 

[stratomaster]

Put a 250k audio pot wired as a voltage divider in an enclosure with 2 jacks. Send that to him and have him place it in the effects loop. He'll now have a master volume control.

Alternatively, a passive volume pedal or an EQ pedal run flat will work with the gain slider being the volume control.

[DeepBias]

A friend in another state has a classic 50.  Its too loud...

I own a 410 classic 50, how could it be too loud using the Pre/Post volumes?

Problematic and prone to "flame-out" is a subjective opinion  as many people find them reliable and a tone machine, also liked for its durability making it suitable for gigging and live performances. The guys at the jam place I was used to go were only using Classic 50 in their locals. Seriously, those Classic 50 run very hot and most common problems are related to loose or cold solder joints on the board, especially where the power tubes connect. You are correct to say prone to flame-out just like several pcb based tube amp, but problematic.. I never had a single issue with mine, this is an old one.

Put a 250k audio pot wired as a voltage divider in an enclosure with 2 jacks. Send that to him and have him place it in the effects loop. He'll now have a master volume control...

Oh man, such a great idea thank you!