I also have a 1971 y ba - 1 amplifier and I was just wondering my treble and bass controls do very little if anything at all, do you think that these need to be changed out and do you think I need to change the value from what the original ones are?
That is a common topic as that trait also applies to old 4 input Marshall and tweed Fender Bassman tone controls. They are very passive, and don't do much, but you should be hearing SOME tone alteration. In your case, check to see that the 'low range expander' (which in these amps is the midrange control) has its connections in place, and that the pot itself isn't damaged with an open connection, one of the tabs on the midrange pot is grounded, and if that ground connection is broken, the tone knobs really will not work.
@@jothanankrogh Great thanks for the input. I'm gonna open it up tomorrow and see what's going on and I'll definitely check that. Other than that I think it's the loudest 50 watt amp I've had or played through. I think a master volume would serve this amp well. Thanks once again for your help.
My amp has the original filter caps and I have been reading thAt when changing these that it is better to change the values, there are 2 capacitor cans of 2 x 40uf 450 wv each can. I read where it's better to use a single 50uf 450wv capacitor for each cap can. Any input on this? Thank you.
Ron, I don't think you should make any changes that give any particular section less filtering, as you can see around 6.00 and 16.00 I explain the can section arrangements before(which may be a bit different in your amp) and after, and even tho I changed the actual arrangement of the various capacitors, the capacitance in each section remains the same. To your specific question I would say a single 100uf can could replace the 40+40 can with the sections connected parallel.
