Advertisement

BigBottoms
BigBottoms
F
OCTAVE
X Type:
Build Level: Intermediate
Based On: EHX® Octave Multiplexer™
The BigBottoms is based on the vintage 3-knob EHX® Octave Multiplexer™. It creates a monophonic
octave down and sounds excellent with guitar and bass. The BigBottoms adds an additional output
gain stage with level control for extra flexibility.
LOW: Sets the amount of low end present in the octave down voice. This control is disabled when
the Sub switch is off (left).
HI: Sets the amount of high end available to the octave down voice.
BLEND: CCW: clean signal, 50% equal amounts of clean and octave down, CW: octave down
only.
LEVEL: Output control.
SUB: In the off position (left) the Sub switch deactivates the LOW control. In on position (right) the
LOW control becomes active and allows for additional tone chaping of the octave down.
Terms of Use:
You are free to use purchased BigBottoms circuit boards for both DIY and small commercial operations. You may not offer BigBottoms PCBs for
resale or as part of a "kit" in a commercial fashion. Peer to peer re-sale is fine, though.
Technical assistance
for is available via the
available to respond via email in a timely and continuous manner, and (2) posting technical problems and solutions in the forum creates a record from which other
members may benefit.
All copyrights and registered trademarks are property of their original owners. Any mention of trademarked or intellectual properties in this documents is purely for
comparative purposes.
Overview
Controls
madbeanpedals
forum. Please go there rather than emailing me for personal assistance. This is because (1) I'm not always
Last Updated:
November 22, 2024 6:11 PM
© 2024
madbeanpedals

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the BigBottoms and is the answer not in the manual?

Questions and answers

Summary of Contents for madbeanpedals BigBottoms

  • Page 1 Terms of Use: You are free to use purchased BigBottoms circuit boards for both DIY and small commercial operations. You may not offer BigBottoms PCBs for resale or as part of a “kit” in a commercial fashion. Peer to peer re-sale is fine, though.
  • Page 2: Parts Layout

    Parts Layout BigBottoms pg. 2...
  • Page 3: Component Values

    Component Values BigBottoms pg. 3...
  • Page 4 Traces - Outer BigBottoms pg. 4...
  • Page 5 Traces - Inner BigBottoms pg. 5...
  • Page 6 Wiring The BigBottoms is compatible with both the SSBP and SSABP bypass boards available at madbeanpedals. The wiring is the same for both. BigBottoms pg. 6...
  • Page 7 100n 1n4001 100k 100n Transistors 100n 2n5457 150n 2N5088 150n LM324 4558 4558 100k CD4013 100n Switches On/On Pots BLEND 100kB 100n 100kB 100n 100kB LEVEL 100kA 220uF 100n 47uF 220uF 220uF 680R 100k 470R 180k 150k BigBottoms pg. 7...
  • Page 8: Shopping List

    4558 CD4013 DPDT On/On, Pin Mount 100kB PCB Right Angle 16mm 100kA PCB Right Angle 16mm Additional Hardware (1) 125B enclosure (2) 1/4” mono jacks (1) Slim 2.1mm DC jack (1) Standard 3PDT footswitch (1) 5mm LED BigBottoms pg. 8...
  • Page 9 This is probably not a total beginner project but otherwise it is a simple and straight-forward build. Anyone with a couple solid builds under their belt should be able to BigBottoms themselves easily. Q1 can be either a through-hole 2n5457 or its SMD counterpart. The the surface mount, the gate is soldered to the square pad and the drain and source are soldered directly to the through-hole pads.
  • Page 10: Circuit Voltages

    4.48 4.52 4.52 1.53 4.53 5..42 0.94 4.47 9.01 4.51 CD4013 4.46 5.11 4.42 4.48 4.46 4558 5.33 2.26 4.53 4.52 7.55 4.52 4.48 4.56 7.45 9.01 9.01 • 9.5vDC One Spot • Current Draw ~ 9mA BigBottoms pg. 10...
  • Page 11: Drill Template

    Coordinates are denoted in (X,Y), drill size format starting from the center (0,0) location of the enclosure. Tayda drill template: https://drill.taydakits.com/box-designs/new?public_key=Q3haaUdHemZTY1p6d0ZQN1NKY0hqdz09Cg== Hardware 125B enclosure Mono jacks Slim 2.1mm DC jack Standard 3PDT footswitch 5mm LED NOTE: Different 1/4” and DC jack styles may require different sized drill holes. BigBottoms pg. 11...
  • Page 12 Build Pic BigBottoms pg. 12...
  • Page 13 Schematic BigBottoms pg. 13...

Table of Contents