mods on the bassman

[drew_half_empty]

well you know how it is, time goes on, preferences change, blah blah blah

anyhoo, what i'm wanting is more gain, and a mid knob that's more than just... annoying

keep in mind this is a '74 bassman 100

so i've done some research & come across some mods that i think will give me what i want

as for the mids, after looking at a schematic it looks like the mid pot is only like 10k, so changing it to 50k should give me the range i'm after

for the gain, the schematic shows 47k plate load resistors, so changing them to 100k should give me some more drive

so... sound good? think the load resistors will give me a good deal more gain or should i do some other gain mods as well?

thanks

 

[the guy who invented fire]

Re: mods on the bassman

Good luck with it Drew, buit let me give you some advise...BF/SF FEnder amps can't dal with a 50k midrange pot...25k is about the max...

 

[drew_half_empty]

Re: mods on the bassman

ok, 25k it is

 

[ES350]

Re: mods on the bassman

Just tweaked a mod like this on a SF Pro Reverb...25K is a good value, 50K gets ridiculous. Other things you might try are 1.5-2 meg input resistors and changing one side to a .02/.02/250/56K tone stack ala tweeds...

 

[TimmyPage]

Re: mods on the bassman

If the issue is with gain and mids, why not try a pedal in front of the amp rather than modding it?

 

[Fresh_Start]

Re: mods on the bassman

ES350 has a good suggestion. If you want to play with the tone stack, Duncan's tone stack calculator is a great way to find a starting point. For example, the "slope resistor" has an impact on mids in addition to the mid-pot/resistor. (That's the 56k ES350 referred to, instead of the stock 100k seen on the schematic.)

Start with the "Fender" model, and play with the values. You might want to start with the Marshall model for earlier Bassmans because there was a cathode follower in front of the tone stack, but not in the Bassman 100.

Hope this helps,

Chip

 

[drew_half_empty]

Re: mods on the bassman

If the issue is with gain and mids, why not try a pedal in front of the amp rather than modding it?

some things pedals just can't do

 

[75lespaul]

Re: mods on the bassman

some things pedals just can't do

True dat.

 

[aleclee]

Re: mods on the bassman

If the issue is with gain and mids, why not try a pedal in front of the amp rather than modding it?

You obviously aren't familiar with the soap opera of Drew and the modded Bassman (Bassmen?).



Dude, for Pete's sake, if the amp isn't doing it for you, at least consider buying a new amp!

IMO, clinging to the Bassman and making a long string of mods is counterproductive and probably more expensive in the long run than "thinking outside the Bassman". Instead of trying to turn an amp into something that it's not, why not look around to see if there's another amp that nails your sound without breaking out the soldering iron?

If you get off on modding the amp, that's cool but at some point it becomes more about playing electron mechanic and less about actually pursuing the tone in your head.

 

[Vasshu the humanoid typhoon]

Re: mods on the bassman

Happy never he will be...yes yes

 

[Empty Pockets]

Re: mods on the bassman

The thing is, no other amp sounds like a Bassman. He still wants it to sound like a Bassman, he just wants to improve a few key things.

If you dunno what i'm talkin about...go find yourself a bassman to play.

 

[Vasshu the humanoid typhoon]

Re: mods on the bassman

Bassmen Comes in various outfits.....they all sound differently!
He is chasing his own tail...again

 

[drew_half_empty]

Re: mods on the bassman

this bassman has only been modded once. The one that got modded all the time was a bassman 50 and i've since sold that

and i'm not trying to change what it does, i'm just trying to tweak it a little bit

i hardly think changing 3 parts is asking for a whole different amp

 

[Stratman]

Re: mods on the bassman

http://www.lynx.bc.ca/~jc/bassman.html

Fairly nice modifications to a early bassman. Notice the 25K pot for presence, which is normally 10K on those bassmans that had a presence pot (Not all do!)