68' bassman basket case project. What should I do?

Howdy folks. I find myself in a quandary here, and I am at your mercy for opinions.
I happened to end up with a pretty jacked up bassman head. AB165 circuit, (Drip edge model)
Original iron, but the rest of the circuit has been tampered with, and according to the dude I bought it from, restored to original spec.
All of the blue caps are gone, and replaced with orange drops, and lots of other modern components. I traced the circuit out, and it indeed appears to be AB165 to the T. It was motorboating like crazy when I got it, but I have sorted that out, and it works wonderfully.

Here's the thing though. It is missing the front cover, the rear cover, and the headshell has been peeled like a grape. So no vintage original value here. Awesome sounding amp, but it's not a keeper for me cuz it's not really my thing. I'm more of a high gain amp enthusiast, but I like working on amps. I'm wondering what would be the most desirable thing to do with this diamond in the rough. I've got a few ideas outlined below.

1. Mod the bass channel into a marshall 2204/plexi preamp circuit, leave the AB165 normal channel, and redo the headshell.

2. Mod the bass channel into a marshall 2204/plexi preamp circuit, leave the AB165 normal channel, and build a sweet combo. (I have access to CNC equipment, a spare v30 speaker, a crap ton of spare parts, and mad skillz.)

3. Leave both channels OG, and redo the headshell.

4. Leave both channels OG, and convert to combo.


All of the above with AA864 variants


The faceplate is pretty trashed as well, so I have no issues drilling holes for mids and MV. I'm planning on making/printing a new one anyways. I'm thinking grey bronco tolex, with walnut veneer or brass faceplate, and black piping.

Any other ideas are welcome. This thing has been sitting awhile, and I'm ready to make something of it. It has also been completely defiled already, so nothing is off limits.

Let me know what yall come up with.
 
I'd probably ask a company like stoneage cabinets to bring it back to original spec. It will be worth a lot more converted to 68 original vintage bassman specifications as much as possible. Those guys have an attention to detail for this kind of stuff. You've admitted the circuit isn't your thing, so I wouldn't go modifying an original real bassman to fit your needs - that's what amp kits are for. If it has the original iron, there's a lot of value to still be had in original spec. Only if a transformer was toasted would I consider bastardizing an original bassman. Just my 0.02 - restore it to original as much as possible, and recoup the value. More original, the better.
 
I don't think Blackface/Silverface Bassman amps are really collectible or anything so I wouldn't worry about value. I have a BF Bassman and I completely gutted it and rebuilt it with G10/FR4 sheets (the old circuit cards can develop problems and mine had). I made mine such that the Bass channel was like a Blonde Bassman but tweaked for guitar and the Normal channel was like a typical Blackface guitar amp without Reverb or Tremolo.

You'll have to change the NFB because the Bassman had that weird NFB that was opposite phase than most guitar amps. If you just mod it to look like a BF guitar amp the amp will howl upon startup unless you switch the polarity (like swapping the OT primary wires at the sockets).

Also, unfortunately these only have a 4 ohm speaker out. That always becomes an issue with me and I literally have a special cab just for this one head. So that right there would sway me towards a combo but I generally prefer heads. But don't under estimate how much of an issue this is. Mine sounds noticeably weak and shitty into an 8 ohm load.
 
I have a home made Bassman 1x12 combo. Used it a lot at rehearsals. Really sounds good. Hung in there easily with power tom drums and full stack of bass and 2nd guitar.

It's the same size as the regular head shell but is around 24" tall with around 17" of that being a sealed back speaker cab. I would make the front opening for the head oversized and try to isolate with rubber the best you can.

I like the transformers Fender used. The 6L6GC's are cool too. I say revoice both channels to use as a clean power amp but still have a bassy and trebley channel. Maybe jump them together? Put an AxeFX, Kemper, or whatever in front. Or running it as a monitor amp for recording with plugins and a reamp box works titties also.
 
PatF":261jso5x said:
Spider Wars, I thought bassmans were 8 ohm and the Champs and Princetons 4?
Easiest way to remember is that Fender almost always used 8 ohm speakers (4x10 being an exception). Bassman cabs had 2 speakers, so 4 ohm.

EDIT: Correction, the 4x10 amps used 8 ohm speakers as well.
 
Sorry dudes. I kinda went AWOL on this. Got busy, and let it sit for a while. Back to it now, and I wanna leave it AB165. As I said in my first post, It was blowin me up when I got it. I fixed that by disconnecting the NFB loop via the .1 uf cap where it meets the bypass cap. I found a couple of bugs in the circuit since then. as I said, it was highly tampered with before I got it. Everything seems OK, and sounds wonderful until I hook the NFB loop back in. As soon as I do that, everything goes silent. It used to motorboat when I did that, but I must have fixed something, and caused another issue. Whatchall think, and should I post a new topic on this? Or continue on this one?
Sorry, I'm not a forum guy. I never think of posting until I'm in desperate need.
 
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