Professor Tweed and Umble tweaks

[Uma Floresta]

Just thought I'd share some tweaks I've made to the Runoffgroove Professor Tweed and Umble. On the Professor Tweed, I've just upped the first and third coupling caps to 100n to make it sound fuller, like a 5E3 Tweed Deluxe. I also added an external pot to control the amount of highs rolled off at the output - this way you can kind of customize it to the brightness of your amp.

My changes to the Umble were much more extensive. I've added switching to change the tonestack to mimick that of a Bassman, Super Reverb and Deluxe Reverb. Basically this means altering the frequency of the mid scoop. I didn't change the actual layout of the tonestack - just used the Duncan Tonestack Calc to confirm that the frequency response matched the Fenders in question.  I also added the low-pass control at the end, as in the PT (though it's not in the schematic), and increased the size of the bypass caps and some of the coupling caps. It really does sound quite Fender-riffic now, with no taint of Dumble to be found. 





Unfortunately, I can't record any clips because my computer is down. Here are some pics - my tolex job was kind of sloppy, but I guess it's good enough for rock and roll.

[svstee]

Very nice! I was looking at building the proffesor tweed, I'll have to try your mods.

[Uma Floresta]

Very nice! I was looking at building the proffesor tweed, I'll have to try your mods.

The coupling caps had a bigger effect on tone/gain than any other change I made.. It might be worth putting the first one on a switch as well - say between 22n and 100n.

[kurtlives]

Cool mods, nice work.

Stock the PF isnt very 5E3ish imo. I found it lacking in the low end and dosent have the creamy kinda loose gain that the real amp does.

I like mine, I did a few mods too. Builing a real 5E3 soon though! Ill have to see how the pedal compares  .

[Uma Floresta]

Cool mods, nice work.

Stock the PF isnt very 5E3ish imo. I found it lacking in the low end and dosent have the creamy kinda loose gain that the real amp does.

I like mine, I did a few mods too. Builing a real 5E3 soon though! Ill have to see how the pedal compares  .

Thanks! Yeah, that was my main issue too - not enough bass on the Professor Tweed, especially when using a single coil bridge pickup. Mine has plenty of bass now, though.

[Uma Floresta]

Here's an excerpt of the Professor Tweed "Deluxe." This is just an excerpt from a song I am in the middle of recording, called "Our Pistols Are Useless." It's being played into a clean software Fender Twin Reverb patch, with some reverb and delay. Using a Fender Tele with flatwound strings.

http://soundclick.com/share?songid=7727958

I hope to have a demo of the Umble/Super Bassman up soon.

[meffcio]

Are You able to record how those two sound in front of just the power amp? Or only a cabsim? i want to know are thay capable of some clean tones as a preamps.

[Renegadrian]

Sorry for the OT
I wanna see better pics of that Vibracaster you got there...

[frequencycentral]

Sorry for the OT
I wanna see better pics of that Vibracaster you got there...

It's an OLC Darth Fader. http://olcircuits.com/olc_darthfader.html

[morcey2]

Getting rid of the 220k resistor in the super bassman will leave you with a floating gate.  It needs a ground reference of some sort or you'll eventually burn it out or get no sound.

Matt

[starekase502]

tell me about the spring king it looks modded and looks like you addes line out to go into another tank.  are you running two tanks? sorry for the ot

[kurtlives]

Getting rid of the 220k resistor in the super bassman will leave you with a floating gate.  It needs a ground reference of some sort or you'll eventually burn it out or get no sound.

Matt

Pretty sure that 220K is just part of a RC network and not actually a gate stopper at all.

The volume control provides the ground reference.

[Uma Floresta]

tell me about the spring king it looks modded and looks like you addes line out to go into another tank.  are you running two tanks? sorry for the ot

Yes, it runs out to a full-size (17") reverb tank. I have a switch on the side that goes between both. Live you'd want to choose one or the other, because the big tank needs a lot more signal than the small internal one, and switching between the two involves a bit of knob twiddling.

[Uma Floresta]

Are You able to record how those two sound in front of just the power amp? Or only a cabsim? i want to know are thay capable of some clean tones as a preamps.

I tried it just in front of a cab sim, but it sounded dark to me, at least with the sim I was using. They are capable of clean tones.

Having lived with these longer, I really prefer the modded Professor Tweed, which sounds great with both single coils and humbuckers. The modded Umble/Bassman thing seems to only sound good with single coils, at least as it is now. I'm considering just removing the tone stack altogether and making it into kind of a Professor Tweed with an extra gain stage. It seems I'm always tweaking the EQ controls on it, whereas the PT Deluxe is kind of set it and forget it.

I also find that I'm running the output lowpass filter wide open on both of these, so that might be something that can be eliminated.

[Uma Floresta]

Sorry for the OT
I wanna see better pics of that Vibracaster you got there...

It's an OLC Darth Fader. http://olcircuits.com/olc_darthfader.html

Yup. Which is basically the Tone God Bullitt minus the extra tube and tone stack.

[Uma Floresta]

Another update - I ditched the tone stack on the Umble, made the first and second JFET stages running parallel into the third, and made the caps on stages 1, 2 and 4 100nF. I also added a 5E3 style tone control and added gain control for both of the parallel JFET stages. This does a better 5E3 sound than the Professor Tweed now, so I'll probably take the Professor back to stock for variety.

Clip:

http://soundclick.com/share?songid=8656717

[Uma Floresta]

And here's a very rough modified schematic to show what's going on there now.

[mat]

Another update - I ditched the tone stack on the Umble, made the first and second JFET stages running parallel into the third, and made the caps on stages 1, 2 and 4 100nF. I also added a 5E3 style tone control and added gain control for both of the parallel JFET stages. This does a better 5E3 sound than the Professor Tweed now, so I'll probably take the Professor back to stock for variety.

Clip:

http://soundclick.com/share?songid=8656717

Cool sounds and I liked the playing also  Thanks!

I built the proftweed with the 100n mods but am waiting for the pots to come in from post. After that I can start to debug it 
I'll let You know how it turns out. Will try the mods for my umble-build also.

Mat

[Uma Floresta]

Another update - I ditched the tone stack on the Umble, made the first and second JFET stages running parallel into the third, and made the caps on stages 1, 2 and 4 100nF. I also added a 5E3 style tone control and added gain control for both of the parallel JFET stages. This does a better 5E3 sound than the Professor Tweed now, so I'll probably take the Professor back to stock for variety.

Clip:

http://soundclick.com/share?songid=8656717

Cool sounds and I liked the playing also  Thanks!

I built the proftweed with the 100n mods but am waiting for the pots to come in from post. After that I can start to debug it 
I'll let You know how it turns out. Will try the mods for my umble-build also.

Mat

Thanks! Here are a couple more clips, this time with less overdrive. In the original clip both drive knobs were at maximum. I don't remember the settings on these clips below - maybe half or a little less than half on both drive knobs.

Recently I've also added a switch that will disconnect the first parallel gain stage that doesn't have the tone control, which makes it possible to get even milder sounds as well, similar to the modified Professor Tweed.

http://soundclick.com/share?songid=8661087

http://soundclick.com/share?songid=8661089

[mat]

Thanks for the clips ! Cool sounds  I like the modded umble very much.

I got the build ready with 100n on first and last coupling positions. I had to sub the two (lacking) 22uF as 33uF's. I have the tone maxed but the sound is too dark with my amp. The low strings when played simultaneously makes a very ugly harmonics- tho that might be my amp also. I'll change the first coupling cap to the original 22n and the electrolytics to 22uF and see how it turns out. Btw. it is really hard to bias the last 5457. Turning the 100k trimmer as little as possible jumps the voltage say from 3.5V to 6V. Also the sound changes alot depending of the slightest movement of the trimmer.

Btw. my guitar is Gibson 339 with old school humbuckers. The guitar is guite midrangy.

Mat