I've got a late seventies fender bassman 135. I plugged my bass in a few hours ago, but there seems to be something wrong. There's hardly any volume coming from the amp. I checked the tubes and they seem to be ok, maybe somethings wrong with the speaker?
Any help?
You just need a passive bass, a tube amp, and a metric ton of marijuana and Sabbath worship.
70's... my first incling would be to re-cap the electrolytics in it, that's a problem with a lot of old equipment especially if it hasn't been used in a while (have a look inside if you can and your careful of the high voltages, some of the electrolytic capacitors may even be bulging or leaking which is a sure sign that it's a problem)
Check the solder joints on the speakers and stuff though first (make sure the wire is connected and the solder is a good shiny joint) and if you have any spare tubes, no harm in trying them out.