Rangemaster - FF -TBmkII ques.

Started by jpiddy118, June 02, 2011, 05:53:52 PM

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jpiddy118

Been reading lots of older posts on this... i've built a Ge Rangemaster that i love, and a Ge Fuzzface that i love, but when i try to boost the FF with the RM, it sounds bad... stepping on the RM sucks all the body out of the FF, and i can't imagine it being useful. Def NOT that Led Zep 1 tone the TBmkII is known for.

On paper, this combo should be similar to a TBmkII, with the only major differences being the input & output caps of the RM. Without altering my RM, and before i take the time to breadboard an original TBmkII, are those differences worth it? I guess i'm the only one who can answer that, but anyone else experience this?

FWIW, i love the RM after the FF for a lead boost, a la Sunlion. very Gilmour.

mac

Maybe you should add a switch to change your RM input and output caps. 2 x 0.1uf might do the job.

mac
mac@mac-pc:~$ sudo apt install ECC83 EL84

blooze_man

Yeah, the TB has a 4.7uf input cap.
Big Muff, Trotsky Drive, Little Angel, Valvecaster, Whisker Biscuit, Smash Drive, Green Ringer, Fuzz Face, Rangemaster, LPB1, Bazz Fuss/Buzz Box, Radioshack Fuzz, Blue Box, Fuzzrite, Tonepad Wah, EH Pulsar, NPN Tonebender, Torn's Peaker...

Quackzed

if the tb has a big input cap, you can probably just add a switch to add a bigger input cap to the rm, as the rm output cap will be in series with the tb input cap /adding the 2 capacitances... so the only cap cutting all the low  end would be the rm input cap...
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jpiddy118

Thanks guys, that seems to be the ticket... i have a slightly larger than original input cap in the RM (.01uf) but now i see i need to go much larger. Cool that the output cap in series with FF input will add up!

mac

MMhh... time to modify my RM!!!  ;D

I like TB Q1 sit at 8v - 8.5v. A triple switch cab change RM bias, input and output cap.  ;)

mac
mac@mac-pc:~$ sudo apt install ECC83 EL84

digi2t

Have a look at the Skyripper circuit. It`s got a Rangemaster/Fuzz arrangement. Might give you a clearer picture of what`s going on.

Cheers,
Dino
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EATyourGuitar

I am also a noob but would changing the input cap on the RM make it more of a booster and less of a treble booster?
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mac

Quote from: EATyourGuitar on June 03, 2011, 11:01:56 AM
I am also a noob but would changing the input cap on the RM make it more of a booster and less of a treble booster?

That's the idea. The input stage of a TB2 is fat sounding.

mac
mac@mac-pc:~$ sudo apt install ECC83 EL84

Quackzed

 :icon_redface: wait, i made a mistake. 2 series caps wont add up, thats parallel caps.  :-X
my bad. so you'll probably need to increase both the in and out caps to let more bass through...
sorry about that, off the top of my head i thought it worked...
nothing says forever like a solid block of liquid nails!!!

petemoore

  Making a small input cap bigger requires changing the cap, unless another can be added-parallel underneath the board.
  Making the second value choice smaller than the board mounted value is as simple as seriesing a cap, right onto an SPST switch, 'in' the input wire [cut and splice the parallel switch and cap circuit].
Convention creates following, following creates convention.

mac

If you make the output cap 0.1uf, the series eq with the 2.2uf at FF input is almost 0.1uf.
A 4.7uf at the input could sound similar to a 0.1uf.

Remember that there is a 0.01uf at the TB2 input to gnd that cuts highs.

mac

mac@mac-pc:~$ sudo apt install ECC83 EL84

jpiddy118

Breadboarded this tonight... didnt play with the series caps yet though. Basically added a Rangemaster to an NPN Ge FF i already had wired up, moved the 2.2uf input cap of the FF to the front of the RM stage, with the 0.1uf cap in between stages. I love it! Really fun having control over the gain of Q1 without altering the fuzz attack of Q2/3. 

Brymus

I put my Omega(set for full boost) in front of a FF and same thing really nice drive.
I was just comparing TBMK circuits earlier.
What helps me is to seperate the FF part of the circuit then compare the differences.
I think when building a Tonebender the key might just be to build the FF part and get it biased right, then build the boost,
like what you are doing.
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jpiddy118

so i had some time to fool around with the circuit this morning... best results seem to be:

2.2uF on the input,
0.1uF in series with 3.3uF at junction of RM & FF circuits,
.047uF on output for rounder, fuller single notes.

The TBmk2 .01uF to ground on input didn't seem to do much at all, even with the treble on my amp cranked. Couldn't get Q3 biased at exactly 4.5v, didn't have anything between 3k9 and 8k2 on hand, stuck with the latter for a 6v reading (less sputter), still good tone for just the FF circuit alone.