Bassman with fender coded transformer but also universal voltage selector

[goldenmonkeycolor]

I’m looking at a drip edge bassman Head. It has the original blue molded caps. It has an output transformer dated to 1967 (or 1977) and the power transformer is a Hammond fender one (I think that is either a 1966 or 1976. My worry is it has an aftermarket universal voltage switch installed. It looks kinda old. But it has 117v, 200v, 220v and 230v or something like that.

Could an original blackface bassman power tx be modded with a euro/USA voltage selector? Or could a silverface 1976 Hammond tx be modded to have that? Im trying to figure out what power transformer is in it.

I just found the tube chart sticker says “for export only” Is this an original 1967 export fender

Anything would be interesting!
Thanks!

[sluckey]

Bassman 70, 100, and 135 all had export models with a voltage selector switch.

[Stevem]

X2 with the above.
That's a very late 67 model if it's got the drip edge !

That's likley one of the last made Fender models to still have the good blue coupling caps in them.

The first thing you should do if you pick it up even if the amp plays fine is to change out the bias filter to a 75 to 100 volt one unless it's been done already.

The second thing is to jump out the switch so that it's directly wired for the 117 volt setting and then remove the knob.

This all being said that AB165 model is the worst sound Bassman of the blackface era ( the PI section that both channels feed thru is truly designed for undistored Bass guitar reproduction !) and should be changed back to the match the AA 864 schematic, of course this as you might imagine is a ton of work but can be worth it if you get that amp for a good price!

To me these blackface amps having no power supply rectifier tubes tubes any longer play no where near a true tweed or 60 to 63 model Bassman , in fact I would sooner build a mojotone or such tweed Bassman head kit and maybe spend a bit more and get the sound, feel and tone I want then beable to say I have a 60s blackface Fender in my arsonal!

[goldenmonkeycolor]

X2 with the above.
That's a very late 67 model if it's got the drip edge !

That's likley one of the last made Fender models to still have the good blue coupling caps in them.

The first thing you should do if you pick it up even if the amp plays fine is to change out the bias filter to a 75 to 100 volt one unless it's been done already.

The second thing is to jump out the switch so that it's directly wired for the 117 volt setting and then remove the knob.

This all being said that AB165 model is the worst sound Bassman of the blackface era ( the PI section that both channels feed thru is truly designed for undistored Bass guitar reproduction !) and should be changed back to the match the AA 864 schematic, of course this as you might imagine is a ton of work but can be worth it if you get that amp for a good price!

To me these blackface amps having no power supply rectifier tubes tubes any longer play no where near a true tweed or 60 to 63 model Bassman , in fact I would sooner build a mojotone or such tweed Bassman head kit and maybe spend a bit more and get the sound, feel and tone I want then beable to say I have a 60s blackface Fender in my arsonal!

They also made blackface bassman export models- Why would I remove the voltage selector switch? are they known to fail or something?

And I whole heartedly disagree with you regarding the AB165 circuit- the aa864 is made for clean bass tones- the ab165 has an extra gain stage on the preamp and distorts MUCH easier than the AA864. Have you even played an AB165? because it breaks up MUCH quicker and gets way gainier than the AA864 with the weak preamp gain staging on the normal channel (its just like a fender bandmaster head without reverb or the normal channel of a reverb amp) and i really dont know anyone that thinks the bandmaster is better than anything.

Why do people that like tweed era amps have to call blackface amps less than? Its a matter of opinion- but you dont seem well acquanted with the actual AB165 bassman- sounds like regurgitated and jumbled up ramblings. "AA864 is older- therefore better- therefore dont buy AB165," said somebody trying to sell an AA864. You can convert an ab165 to be exactly the same as an AA864 if you want to anyways. Without any irreversible mods too. So please- I have to deal with people that read this garbage all the time. I had a guy come in the other day and say "i'm not sure I want a blackface super reverb- I've heard the silverface models are cleaner and take pedals much better" it was actually amazing to hear. LIke dude dont listen to other people- buy what sounds good to you. I agree the ab165 has some dumb stuff in it- but it is totally mod able and you get the 3rd gain stage- and the blue molded caps. I guess the shit talking on the ab165 is good for me- maybe I can get a better price on it lol

I like the blackface bassman sound- please dont tell me or anyone else a 1954 tweed is better. its not. its different. completely different. Im not into mushy, shits out when pushed, weak post gain stage EQ- Hendrix playing clone tweed bassman. I like an extra gain stage having- solid state bass thumping- blackface bassman. I like a lot of other amps- I actually like tweeds sometimes (though I really dont think they're useful for anything but a certain sound- definitely not gonna try to play with heavy distortion where I need thump- or clean where I need articulation.

Maybe I'm missing something on modding an AB165 to AA864 specs (but with 3rd gain stage and more filtering)? Is it really that difficult? I dont think so

[sluckey]

You seem quite knowledgeable on Bassman amps. Probably just wasting your time asking questions here.

[andresound]

I have had 2 1968 drip edge Bassman 50w heads, both with voltage selector. One of the heads was called a bassman 50 export

[tubeswell]

Don't have to remove the mains selector. It's part of the package. YMMV - I've got a 73 quad reverb in my stash with a red 6-position rotary mains selector (that is bypassed).

[Stevem]

I posted up that you should jump the switch and remove its knob, NOT remove the switch its self, so please reread what I posted.

My comments in terms of distortion where in regards to the PI section only, and the two 220k inverse feedback resistors from the output tube plates back to the PI.

Your also thinking about these heads for guitar usage and not in terms of how weak in output Fender Bass pickups where back then!

For pure Bass guitar usage in either channel of the black face Bassman amps my preference is a strong testing 12AY7 in the V1 or V2 hole.

Have you every measured the output of a Tele Bass pickup?

Thank for explaining your needs for a tight output stage responce from these amps, but the fact of the matter is that most untechincal players who yearn for a late tweed Bassman think that these blackface amps both in terms of play and sound follow closely in the Tweed's foot steps and as you know they do not.

They do not even have interleaved output transformers any more!

I have spent 35 plus years helping players get the Black and silverface Bassman to do the 5F6-A thing so I know what there alleged about, yes.