I am looking for a decent power attenuator under $80 that can cover a 40W tube amp. Any suggestions?
^ Your going to have to add about 120 to that to get a new one.
don't go cheap on attenatuors, poor ones can damage your amp.
Cheapest I know that will handle your amp is a Weber Mass Lite 100W for $160. However Weber Masses are VERY good attenuators!
check out the ones on weberspeakers.com. I think thats about as cheap as you can get without riskint your amp.