Mad Bean Pedals Mangler User manual

Mangler
FX TYPE: Fuzz
Based on the Fuzz Face
© 2017 madbeanpedals
1.95” W x 1.875” H
Terms of Use: You are free to use purchased circuit boards for both DIY and small commercial operations. You may not offer these PCBs for resale or
as part of a “kit” in a commercial fashion. Peer to peer re-sale is, of course, okay.

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R1 100k C1 2u2 D1 1N5817
R2 33k C2 22uF
R3 220R C3 10n Q1, Q2 PNP GE
R4 470R C4 100pF
R6 4k7 C5 100uF IC1 TC1044SCPA
RPD 1M C6 100n
C7 10uF BIAS 20k
C8 10uF
C9 100n FUZZ 1kC
VOL 500kA
IC
Trimmer
Pots
B.O.M.
Resistors Caps Diodes
Transistors
V
alue QTY Type Rating
220R 1Carbon/Metal Film, Carbon Comp 1/4W
470R 1Carbon/Metal Film, Carbon Comp 1/4W
4k7 1Carbon/Metal Film, Carbon Comp 1/4W
33k 1Carbon/Metal Film, Carbon Comp 1/4W
100k 1Carbon/Metal Film, Carbon Comp 1/4W
1M 1Carbon/Metal Film, Carbon Comp 1/4W
100pF 1Ceramic, MLCC 16v min.
10n 1Film 16v min.
100n 2Film 16v min.
2u2 1Electrolytic 16v min.
10uF 2Electrolytic 16v min.
22uF 1Electrolytic 16v min.
100uF 1Electrolytic 16v min.
1N5817 1
PNP GE 2PNP Germanium Transistors
TC1044SCP
A
1or, MAX1044CP
A
, ICL7660SCP
A
20k 1Bourns 3362P
1kC 1PCB Right Angle 16mm
500kA 1PCB Right Angle 16mm
Shopping List
Subs
You can use a 22k or 25k trimmer in place of the suggested 20k
The TC1044SCPA is the recommended inverter, but you can also use a MAX1044CPA or
ICL7660SCPA. Make sure you get the part that matches the BOLDED SUFFIX.

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1590B Drill Guide
4.43”W x 6.47”H

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Wiring
The -9v, Ground connections on the lower right are courtesy power in case you are doing a 2 in 1
effect that is also positive ground, ex. the Mangler with a Rangemaster or PNP Tonebender. In this
combination, you only need to use one inverter to power both circuits. If you are doing a 2 in 1 and
need help figuring out how to power both, start a help thread on the MBP forum.

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Overview
2017 Changes: Reworked the layout for centralized I/O pads. Added pull-down resistor option back to the circuit. Small
changes in the power section.
Either you love fuzz, or hate fuzz. There is no in-between. Fuzz for life! That said, the Mangler is ½ classic Fuzz Face and
2/3rd other stuff. I double-checked my math on that and it’s solid.
The 2017 edition of the Mangler includes a voltage inverter on the PCB. You can use your standard center-tip negative 9v
power supply to power this positive ground effect without having to use a Road Rage board or other trickery. This takes
out all the guess work for newer builders who have not dealt with positive ground effects before: everything is hooked up
and wired like a normal negative ground effect!
If you have never purchased PNP germanium transistors before, you can find several variations and offerings at
http://smallbear-electronics.mybigcommerce.com/. These transistors are tested for gain and leakage beforehand.
Smallbear also provides resistor values to properly bias the pair of transistors you purchase. Please feel free to use those
values instead of the ones listed in the BOM of the Mangler. The tabs on the silk screen of the Mangler PCB indicated the
emitter of Q1 and Q2.
Calibration
To bias the Mangler, touch the black lead from your DMM to the TP pad under the Bias trimmer on the PCB and the red
lead to any ground point on the circuit. Adjust the trimmer until your DMM reads approximately -4.5v. It does not have to
be EXACTLY -4.5v…but keep it pretty close. One mod: try setting the bias voltage closer to -3.5v or even -3v. This
typically squashes the fuzz down even further for super-compressed violin-like fuzz (a la Eric Johnson). It may not work
with every transistor pair, though.

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Notes
C1, C2 and C3 can be either axial or radial caps. The radial spacing is standard (5mm for C3, 2.5mm for C1 and C2). The
axial spacing is 18mm for C3 and 23mm for C1 and C2. It doesn’t matter with type you use…the axial caps are for pure
mojo.
Q1 and Q2 have four pads for soldering. This is because some PNP transistors have their leads in a triangle spacing and
some are straight across. Just remember that the two pads highlighted below are connected, so solder the middle lead of
your transistor to one of those.
You can also use sockets. For triangle spacing these sockets are appropriate:
http://smallbear-electronics.mybigcommerce.com/to-5-transistor-mill-max/
They are expensive but a lot cheaper than replacing your transistors if you apply too much heat from bad soldering!
For straight-across leads, the typical single in-line sockets can be used:
http://smallbear-electronics.mybigcommerce.com/single-in-line-mill-max/
Mods
There are two optional mods here: RPD and C4.
RPD: This is a pull-down resistor which was not used on the original fuzz faces. It is the “anti-pop” resistor to prevent
mechanical switch noise or leaky input caps from making a pop when using a 3PDT for bypass. You can socket this
resistor and decide if you need it or not. If you have no pop, then you can safely leave it off.
C4 is an optional small ceramic cap to reduce noise or hiss you might experience with PNP transistors in a high gain
circuit. 100pF is a good starting point, but some may find it makes the fuzz dark sounding. You can use smaller value
caps such as 47pF, 22pF or 10pF to see what works best. Or, not use it at all. It depends on the particular pair of
transistors you have whether or not this mod is of any use. A socket for C4 is a good idea!

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