BSIAB/Aaron Nelson Booster 2.5/Tubescreamer tone control questions!

[jamiefbolton]

Ok guys, I have a few questions and/or discussion topic.

I've recentlty breadboarded and built some TS style pedals. I like the sound of a TS, well kinda. It is too mid-rangy.  We all know the sound. I've changed out caps all throughout the circuit and nothing seems to help all that much.

So I breadboarded the Aaron Nelson Booster 2.5 (original idea from Jack Orman). The BSIAB2 is very similar to the Booster 2.5. The Booster 2.5 was ok. Not great, but just ok.  I then added the "marshall filtering" (10k resistors and .0022uf caps) from the BSIAB2 and the 1uf cap leading into the tone control. I'm liking this a lot.

So this leads me to the question and the quest for a TS style pedal tailored to my taste.  How can I incorporate the Big Muff tone control and the "marshall filtering" into the TS circuit. The TS tone control is coming off the opamp and i'm not good enough to know how to use the BMP tone with a TS circuit. can this even be done? or will it just sound like crap?

specifically, i was using an Eternity schematic, but the TS style/inspired pedals are just about the same circuit with differences in part values.

if this has already been discussed, please point me to that discussion. i have not seen one though.

thanks

jamie

[John Lyons]

You will have to start from scratch  for the most part.
Just take the first op amp section of the Eternity
and connect it to the big muff tone control.
Then use the second half of the op amp to boost
the volume of the circuit since the BM tone section
eats up a good bit of volume. Should be cool!

John

[jamiefbolton]

So are you saying to "reverse" the schematic. Put the clipping where the tone is now, and put the new tone control where the clipping is?

(schematic linked below) **thanks to lovepedal detective for the schematic
http://i239.photobucket.com/albums/ff314/lovepedaldetective/LovepedalEternitySchematic.gif

[John Lyons]

The two op amp sections don't care which comes first.
In that schematic IC B comes first but it does not matter which
section you use first.

The circuit I was thinking of would go like this:
Clipping op amp half (Everything to the left of the 1k at pin 7 [which
would/could be pin 1...]) then the big muff tone stack, then the other half of
the op amp set up like a clean boost to kick up the volume.

John

[jamiefbolton]

i see. cool.

where could i find a good little clean boost using an opamp. i know some for a JFet and all, but not sure about opamp clean boost.

[jamiefbolton]

i've searched for opamp gain stages but i can't seem to put it toegether. any suggestions?

[CynicalMan]

www.montagar.com/~patj/preamps.gif
www.jer00n.nl/electronics/simple-opamp-based-guitar-booster

[jamiefbolton]

www.jer00n.nl/electronics/simple-opamp-based-guitar-booster

ok so will i drop in the entire schematic after my BMP tone control. I wouldn't need the first resistor and cap would I? Aren't those just input cap and pulldown resistors?

i'm working on an all inclusive schematic once i get this part figured out.

[jamiefbolton]

will this work. am i even close?

[John Lyons]

Some of the values for the eternity section you have aren't correct.
I know there are a few versions but the input cap should be .047 or lower
I think. An the gain pot is 500k or 1M not 100K.

You may have to play with the 10uf/100k/50K pot
at the sceond op amp. You may need less gain.
Smaller pot + less gain.
You also may find that the 10/.002 filters at the end do
not sound good in this circuit. There is nothing specifically
"Marshall" about them. They just cut out some high end
sizzle. You may not need that filtering...

Try it out!

[jamiefbolton]

yeah i've substituted some different values that what is normal. ie input cap.  i like a .1 better there. and i miswrote the gain pot value. it is 500k.

i put in the 10k/.0022 because i like it for my booster 2.5 thought about trying it here just to see what happens.

will i need a decoupling cap after the tone control?

i'm going to breadboard soon i hope

[John Lyons]

Ok. I see.
Oh...yes, you should put a cap after the tone control.
.1uf should be fine.

john