What circuit is this bassman?

[jtgainor]

Looking at taking a modded bassman in on trade. Was told the channels were jumped but trying to figure out what else was changed. Any help is appreciated!

 

[Geo]

That's a mess bro.

I would say, start from scratch.

 

[glpg80]

Will need better pictures to see resistor band colors to know exactly but it doesn’t look like much of anything has been left untouched. The whole preamp has been changed in some shape or manner. Looks like the channels have been jumped like you said to give more gain stages and some rework done to the phase inverter. There’s not a single untouched component in the preamp though.

I agree with others - I’d stay away if you weren’t intending on a complete board replacement.

 

[TheBiggestJerk]

Did Jim Marshall clone the Bassman to make the JCM?

 

[marvcus]

JTM45

 

[DanTravis62]

It definitely looks jumped but there's a ton of other shit going on in there, with very little that's obvious enough to tell what exactly it is

Also as @glpg80 mentioned there's a bunch of non stock (at least compared to an ab165 or similar) stuff going on in the PI too

What year is the bassman? If it's got the original iron its still worth something for sure but it's a risk seeing as you don't have any documentation to what was done

 

[jtgainor]

It definitely looks jumped but there's a ton of other shit going on in there, with very little that's obvious enough to tell what exactly it is

Also as @glpg80 mentioned there's a bunch of non stock (at least compared to an ab165 or similar) stuff going on in the PI too

What year is the bassman? If it's got the original iron its still worth something for sure but it's a risk seeing as you don't have any documentation to what was done

It’s a 69’ supposedly. I’m after an ab165 circuit I think anyways so I think I’ll pass on it.

 

[DanTravis62]

It’s a 69’ supposedly. I’m after an ab165 circuit I think anyways so I think I’ll pass on it.

There's a relatively clean 65 with 2x12 local to me on FB marketplace

https://www.facebook.com/share/1EyVP5NPGN/

 

[Kelly]

Did Jim Marshall clone the Bassman to make the JCM?

He copied the tweed Bassman/Twin. Nothing like the blackface amps.