Bass Amp Project

[skeezbo]

Another newbie here and I need some advice. I got a Fender Bassman 100 to use for gigs (for bass), but it seems underpowered. I used a Blackface Showman back in the day, so I thought this would cut it.

The normal channel has surprisingly low gain, and the plate voltages on the power tubes average only 425. Is this standard? I blackfaced the inverter, but that didn't seem to improve the headroom. I had some KT66HPs in a tweed build that seemed to have some extra thump. I think those will help, but I would consider 6550s (and an auxilliary heater supply) or some different transformers if it could provide enough power and be reliable. Ampeg V4Bs used 7027a tubes, which are back in production. Any advantage to wiring the sockets for those?

Can you offer suggestions, please? It is probably morally wrong, but It might be fun to convert it for guitar...maybe a 4 6v6 Liverpool? I sure would like to use a tube bass amp, and an SVT is just too big and heavy.

Thanks in advance,
Skeezbo

[UR12]

Personally, I think that one of the best sounding bass amps ever built was the Ampeg B15 Portaflex. It was designed by Jess Oliver, who made an appearance at the NJ Ampfest back in November If you could combine the preamp of the B15 to a high wattage power section I think you might have something.

[skeezbo]

I do have some NOS 6SL7s in reserve and an Ampeg bass preamp schematic in one of the TUT books. There is plenty of room in the chassis for octal preamp tube holes...hmmm...I could set up channel 1 (Bass and treble only) as an Ampeg channel....
More to think about! (My favorite part--I've fantasized about way more stuff than I have built!) Thanks for the idea.
Skeezbo