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I've been working on this build for a while now and finally it's close to finished. This is the amp that I built for an upright player, used the bassman 20 schematic but, not knowing enough about sizing up a transformer myself, I was told to use the deluxe BF PT and OT and so I set it up with a fixed bias with the adjustable bias pot.. tube rectifier...
Earlier I had posted when I went through converting it to a full wave rectifier and put in the hum balance pot the bassman 20 schematic called for, and biased it to about 18mA on the plates and it started sound great.
Here's my question, I'm not using a 15" speaker like the bassman 20 instead I'm using a 12" and the problem has been finding the right one, does anyone have any advice on sizing an amp like this with a suitable speaker?
So far we've tried an eminence basslite S2012, with the previous rectifier. (I'm thinking of going back to this one now that it's biased a lot lower and it has th e SS rectifier).
Is there some sort of magnet size , in ounces, that I should be considering?
We tried a speaker with a huge magnet with a diameter of about 8". This seemed to work well enough but the volume is not great.
Anyway, thanks in advance for any of you opinions?
pete
Earlier I had posted when I went through converting it to a full wave rectifier and put in the hum balance pot the bassman 20 schematic called for, and biased it to about 18mA on the plates and it started sound great.
Here's my question, I'm not using a 15" speaker like the bassman 20 instead I'm using a 12" and the problem has been finding the right one, does anyone have any advice on sizing an amp like this with a suitable speaker?
So far we've tried an eminence basslite S2012, with the previous rectifier. (I'm thinking of going back to this one now that it's biased a lot lower and it has th e SS rectifier).
Is there some sort of magnet size , in ounces, that I should be considering?
We tried a speaker with a huge magnet with a diameter of about 8". This seemed to work well enough but the volume is not great.
Anyway, thanks in advance for any of you opinions?
pete