Project · Boosters & Volume
Mini-Boosters
Here are some variations on the JFET Mu amp booster made famous by Jack Orman at amzfx. We call it Jack of all Mini-Boosters, mostly as a tribute to Mr. Orman, but also this circuit board will accommodate many variations. We have shortened the name to the acronym JOAM in some cases.
AMZ Mini-Booster
This is the one that started it all. Jack took the rough design of this JFET Mu amp from an ancient National Semiconductor App note (see bottom of page 5) and refined it into this wonderful booster for guitar. There is lots more information available about this booster at
amzfx Lab Notebook.
Project files
Everything you need to build it
Jack Of All Mini-Boosters Ready-For-Transfer Printed Circuit Board Layout File Please Note: This Ready-For-Transfer PCB layout file is not needed if you are buying the Ready-For-Transfer Printed Circuit Board from us.
Schematic
Schematic


Parts layout
Parts Layout / Wiring Diagram


What you will need
Bill of Materials
Version 2010June14 · Copyright 2010 JD Sleep · Permission refused for posting/serving this file from any site other than www.generalguitargadgets.com · Trademarks are property of their owners
Resistors
| Resistor ID | Value | 3-band Marking | 4-band Marking |
|---|---|---|---|
| R1 | 1M | brown-black-green | brown-black-black-yellow |
| R2 | 1M | brown-black-green | brown-black-black-yellow |
| R3 | 1M | brown-black-green | brown-black-black-yellow |
| R4 | 100 ohm | brown-black-brown | brown-black-black-black |
| R5 | 1k | brown-black-red | brown-black-black-brown |
| R6 | None | ||
| R7 | None | ||
| R8 | 1k | brown-black-red | brown-black-black-brown |
| R9 (Volume Control Potentiometer) | 100k Log |
Capacitors
| Capacitor ID | Value | Type | Possible Marking |
|---|---|---|---|
| C1 | 0.047µF | Film | 473 |
| C2 | 3.3µF N.P. | Aluminum Electrolytic Non Polarized | 3.3µF |
| C3 | 0.22µF | Film | 224 |
| C4 | 100µF | Tantalum or Aluminum Electrolytic | 100µF |
| C5 | 10pF | Ceramic | 10 |
Potentiometers
| Part ID | Value | Type |
|---|---|---|
| R6 - Volume Control | 100k | Log (Audio) Taper |
Other
| Part ID | Part Name |
|---|---|
| Q1 | 2N5457 (or J201) JFET Transistor |
| Q2 | 2N5457 (or J201) JFET Transistor |
| D1 | none |
| D2 | Status Indicator LED and holder |
| J1 | Stereo quarter-inch jack |
| J2 | Mono quarter-inch jack |
| J3 | DC Jack |
| B1 | 9 volt battery |
| Sw1 | Heavy Duty 3PDT foot switch 9v battery snap, Printed Circuit Board, 24 gauge stranded wire, Enclosure, Knobs |
More about this project
Notes, sounds and related links
Boutique Boost
This is similar to the first version of the Fat Booster. It has the input Gain control and a tone control added to the design.
Common File For AMZ Mini-Booster and Boutique Boost

Ready to build? We have the kit.
Would you like a Ready to Solder Circuit Board for this project?