Blasphemous AB165 Bassman Mod Concept

[StratKid]

I have fallen in love with my buddy's 1965 Fender Bassman Head. He just offered to sell it to me. I love cranking it and letting it sing but I love the cleans too. I have been doing some research and thinking and i have a concept for a mod but I am not sure it would work. Basically I was thinking I could install master volumes for each input. The bass input would have the "volume" cranked for some distortion while the normal input would have the "volume" set lower to maintain cleans. Then I could use the master volumes for each input to balace the overall volume between the inputs. I could then use an ABY stompbox to control which input was being utilized, so it would sorta function like an amp with 2 channels. I will add a diagram to try to illustrate my idea. Is there any way in hell this could work? Thanks!

[ArtieToo]

Re: Blasphemous AB165 Bassman Mod Concept

It should work fine, but . . . for what you want, you don't need, (or want), the "Y" functionality. That leaves just A/B, which means just a simple SPDT switch. Add a pot to one of the outputs, and you have all you need in one cheap DIY box. Switch, pot, and three 1/4" jacks, does it all.

Tomorrow, after coffee, I'll post a diagram.

[StratKid]

Re: Blasphemous AB165 Bassman Mod Concept

It should work fine, but . . . for what you want, you don't need, (or want), the "Y" functionality. That leaves just A/B, which means just a simple SPDT switch. Add a pot to one of the outputs, and you have all you need in one cheap DIY box. Switch, pot, and three 1/4" jacks, does it all.

Tomorrow, after coffee, I'll post a diagram.

Thanks a ton. I see what you’re saying.

[Darg1911]

Re: Blasphemous AB165 Bassman Mod Concept

Just like with the Marshalls that were built on the Bassman, jumping inputs allows a blend of the two inputs voicings. I use an ABY on my Marshall build instead of a jumper at the inputs. An ABY allows you to switch between either input and/or to blend the two inputs. If that's something you would like, then go with the ABY. If you only ever use both inputs and never use only one or the other input alone, then just jumper. With my Marshall, I usually don't use the normal input alone but do use the Bright alone as well as the mix of both. An ABY works real well for me. But I do use an active ABY (Fulltone) rather than a passive.

As far as the master volume goes, I don't know if I'd install them on an original Bassman but a re-issue is another story. Regardless, you may also want to look at doing a single, post phase inverter master volume. On it's face, it doesn't seem like a PPIMV would help for wanting the normal input for cleans, but between keeping the bright volume down a bit and working the volume pot on the guitar, it could work pretty well. I only mention a PPIMV because I think additional Pre Phase inverter master volumes suck on an early Marshall (which should also apply, in theory, to the Bassman). But I know that some players do like them so it's all just my personal opinion and preference.

[Nostalgic Distortion]

Re: Blasphemous AB165 Bassman Mod Concept

Yeah man, the Y feature on the A/B/Y pedal would be used to blend the two CH’s together but I believe they are in phase in the AB165 so you’ll be able to get some pretty good tones by doing this. However like Artie mentioned for what you described here you’d only need a A/B switch.

[Rich_S]

Re: Blasphemous AB165 Bassman Mod Concept

I would not drill a blackface Bassman for master volume pots. That head’s a classic and (as you know) sounds great. Don’t hack it up, trying to turn it into something it’s not.

There are many, many great dirt pedals out there these days. Just find one that gives the clean Bassman the dirty sound you want.

Or, if you’re really set on using the amp’s natural cranked-up overdrive, there’s probably an attenuator out there some place that can be switched in and out with a remote switch. That, in conjunction with an A/B, would get you what you want without hacking a classic.

[ArtieToo]

Re: Blasphemous AB165 Bassman Mod Concept

Oops. Sorry. Forgot about this. Diagram tomorrow, checks in the mail, and all that jazz.

[jeremy]

Re: Blasphemous AB165 Bassman Mod Concept

if you want a clean channel and dirty channel, i would only put a mv on the dirty channel. if you want clean, adding a mv to that channel isnt going to help and im a believer in the theory that the less crap you have in the circuit, the more pure the tone.

[StratKid]

Re: Blasphemous AB165 Bassman Mod Concept

Okay I realize now that I would only need one master volume for the whole circuit and an A/B box. I think this’ll work out actually. Does anyone have a recommendation for a cab that would do well with a Fender Bassman?

[StratKid]

Re: Blasphemous AB165 Bassman Mod Concept

I would not drill a blackface Bassman for master volume pots. That head’s a classic and (as you know) sounds great. Don’t hack it up, trying to turn it into something it’s not.

There are many, many great dirt pedals out there these days. Just find one that gives the clean Bassman the dirty sound you want.

Or, if you’re really set on using the amp’s natural cranked-up overdrive, there’s probably an attenuator out there some place that can be switched in and out with a remote switch. That, in conjunction with an A/B, would get you what you want without hacking a classic.

Blasphemous was in the title...

[Nostalgic Distortion]

Re: Blasphemous AB165 Bassman Mod Concept

I would not drill a blackface Bassman for master volume pots. That head’s a classic and (as you know) sounds great. Don’t hack it up, trying to turn it into something it’s not.

There are many, many great dirt pedals out there these days. Just find one that gives the clean Bassman the dirty sound you want.

Or, if you’re really set on using the amp’s natural cranked-up overdrive, there’s probably an attenuator out there some place that can be switched in and out with a remote switch. That, in conjunction with an A/B, would get you what you want without hacking a classic.

If you decide to go the pedal route I highly recommend one of these!!!

I actually have a 5F6 & I can attest to the fact that it sounds very close to the amplifier’s drive & it can be had a a hell of a lot lower volume ..

[StratKid]

Re: Blasphemous AB165 Bassman Mod Concept

If you decide to go the pedal route I highly recommend one of these!!!
[ATTACH=CONFIG]98166[/ATTACH]
I actually have a 5F6 & I can attest to the fact that it sounds very close to the amplifier’s drive & it can be had a a hell of a lot lower volume ..

I have a TS9, Fulltone OCD, and an MXR micro amp pedal. All great pedals but none of them sound like the ab165 I played!

[StratKid]

Re: Blasphemous AB165 Bassman Mod Concept

Also, IMO of course, amp Distortion > pedal Distortion in most cases.

[jeremy]

Re: Blasphemous AB165 Bassman Mod Concept

i agree with that and the 5f6 doesnt sound much like the ab165. a 5f6 cranked with channels jumped is a beast though. for dirty tones, i like celestions with my fenders. i run a g12h30-55 in my '66 deluxe reverb and a g12h30-75/v30 combo in my 2x12 fender cab. it depends on what you are going for tonally and volume wise.

[StratKid]

Re: Blasphemous AB165 Bassman Mod Concept

i agree with that and the 5f6 doesnt sound much like the ab165. a 5f6 cranked with channels jumped is a beast though. for dirty tones, i like celestions with my fenders. i run a g12h30-55 in my '66 deluxe reverb and a g12h30-75/v30 combo in my 2x12 fender cab. it depends on what you are going for tonally and volume wise.

I play mostly rock, hard rock, punk, and alternate. I really like greenbacks and v30s but I’m not sure whether they would compliment a dirty fender or not.