Badmaster gain mod, hey Bob P :o)

[stokes]

Max,an easy way to tame the drive would be to adjust the gain of one or more of your extra stages via the cathode and plate resistors.maybe on the vibrato channel so you will still have the stock normal channel,and still easily reversable.

[Rick Erickson]

Well, tried the voltage divider cable 470K/220K to ground,

Did you try a straight cable into the #2 input yet? That's a 68K/68K to ground voltage divider. With the .1uF coupling cap your -3db point is ~12Hz with this network. Not as much bass shelving as I first thought. Worth trying though. RE

[Satamax]

Hi Rick!

Yes i did, but it's not enough imho, it's just like with the 470/220K cable. Or at least i have the impression. I have tried something like 220/22K iirc, and it's too much. I think something like 300/100, or 470/100 should be pretty close to what i want.

Stokes, i know that would be an easy way, but i want to keep this amp as stock as possible. It's a BF after all!

Bye guys

Max.

[stokes]

"Stokes, i know that would be an easy way, but i want to keep this amp as stock as possible. It's a BF after all!"

I hear ya there,Max. Maybe try putting a lower gain tube in one channel,maybe a 12AY7 or 5751 or AU7,AT7,might tame it enough.

[Satamax]

I was kind of toying with that idea. ECC82 is all i have on hand, or ECC81 I'll see what i can do!

[Ptron]

Thanks for the heads up on this mod, Satamax. I did this to my Bandmaster and it works great. Using the #2 input like Rick suggested I get a decent range of use out of the pots before things start to sound funny.

[Satamax]

Thanks for the heads up on this mod, Satamax. I did this to my Bandmaster and it works great. Using the #2 input like Rick suggested I get a decent range of use out of the pots before things start to sound funny.

Has it got some balls? Do you like it? If yes guys, you can dub it the satamax's mod, as i've never seen it done by anybody before, i've imaginated it myself and drawn the three wires on the schemo and i'd like to have a litle recognition on the net Actualy i'l send it to Larry!

[Satamax]

Hey guys. A litle update.

I finished my dual chanel switcher mod.

Basicaly it's the original mod i did, with a pedal, into wich the guitar is plugged and the signal is sent either to the normal or vibrato (modded chanel) Sounds cool, now it's missing reverb.



Only thing i need to find is a good shielded patch cord.

[Silvertone Jockey]

Bump

It's an old thread, but bump anyway. Anyone try this? If so any useful tweaks to the circuit?

[Silvertone Jockey]

Gonna try this with my TFL 5005D bandmaster tonight only I'm going to reverse it and use channel one to drive channel 2 so I can keep the reverb happening. Well that's my theory anyway. Have a million (OK maybe closer to a hundred or so) different types and brands of preamp tubes to play with from 12AV7 to 12BZ7 and everything in between so I should be able to dial in a nice gain structure with tube experimentation. Will update with results

[Silvertone Jockey]

Well the mod works. Not sure if I like it or not yet, haven't done the tube experimentation and it was late so didn't get to crank it so time will tell on this one

[Chris - CMW amps]

mod: putting one channel IN SERIES with the other?

In theory it should work but there are two problems....
- the shared 2nd cathodes
- the voicing (farty when maxed)

[Silvertone Jockey]

mod: putting one channel IN SERIES with the other?

In theory it should work but there are two problems....
- the shared 2nd cathodes
- the voicing (farty when maxed)

Could you expound on your two points in more detail?

'Noob' yeah that's me. I already get the farty thing, is there an easy way to fix it?

[Alan0354]

I did not read the rest of the posts, just comment on the original post and schematic.

I don't think it is optimized as a channel switching amp.

1) You need a master volume for the clean channel. Or else, when ever you change the volume of the clean channel, you change the OD channel.

2) When you drive the second channel with the output of the first, the signal level can be high as you have to have the volume for the clean channel. You don't have a volume to control how much signal to drive the second channel. Normally, people have a volume they called "Gain".

3) Normally, the tone stack of the OD channel is after all the preamp stages, the tone stack drive directly to the PI stage through a master volume pot. In your case, you still have a gain stage after your last volume control. This make it harder to control the master volume.

4) The fender circuit has a lot of bass in the signal ( which is normal to get good full clean sound). BUT if you have a lot of bass in the first two stages, then you drive the next stages to get OD, you'll get nothing but fart!!!! The lower strings really sound like farting!!!! In high gain, you limit the bass to get distortion and then up the bass as the final stage......This.......you have to thank CHUCK H here. I got this pointer from him and it is so true.

Bottom line, I won't do it this way. I don't know the condition of your Bandmaster as a good one worth some money. I don't know I would mug around it. I sure won't buy a Bandmaster to mod. Go get a Bassman, they are cheaper.

I would start by adding one tube to the OD channel and take it from there and leave the other channel alone. Clean sound of Fender is legendary, I would just use a A/B pedal to switch your guitar between the two channel.

[Silvertone Jockey]

Sounds like crap, not worth modifying anything trying to make it work. It's too far away from good IMO