Project · Distortion
Blue Star
The Blue Star (formally Blue Magic) is a beautiful, mild overdrive. For connoisseurs of fine distortion. Fantastic sound that probably isn't available from other overdrive/distortion units.
Project files
Everything you need to build it
Blue Star Ready-For-Transfer Printed Circuit Board Layout For use only if you are a complete DIY person who wants to etch and drill your own PCB. Otherwise, we recommend you ignore this PCB mask and buy the Ready-to-Solder Printed Circuit Board or Complete Kit from the links below.
Parts layout
Parts Layout / Wiring Diagram
What you will need
Bill of Materials
Version 2015July01 · Copyright 2014 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 | 4M7 (4.7M) | yellow-violet-green | yellow-violet-black-yellow |
| R2 | 2M2 (2.2 M) | red-red-green | red-red-black-yellow |
| R3 | none | ||
| R4 | 1k | brown-black-red | brown-black-black-brown |
| R5 | 4k7 (4.7k) | yellow-violet-red | yellow-violet-black-brown |
| R6 | 470k | yellow-violet-yellow | yellow-violet-black-orange |
| R7 | 68k | blue-gray-orange | blue-gray-black-red |
| R8 | 1M5 (1.5M) | brown-green-green | brown-green-black-yellow |
| R9 | 4k7 (4.7k) | yellow-violet-red | yellow-violet-black-brown |
| R10 | 6k8 (6.8k) | blue-gray-red | blue-gray-black-brown |
| R11 | 22k | red-red-orange | red-red-black-red |
| R12 | 1M5 (1.5M) | brown-green-green | brown-green-black-yellow |
| R13 ( R13T) | 50k trimmer | ||
| R14 | 500k Linear Potentiometer (Drive Control) | ||
| R15 | 50k Linear Potentiometer (Tone Control) | ||
| R16 | 100k Log Potentiometer (Volume Control) | ||
| R17 | 1k | brown-black-red | brown-black-black-brown |
Capacitors
| Capacitor ID | Value | Type | Possible Marking |
|---|---|---|---|
| C1 | 0.001µF | Ceramic or Film | 102 or 1n |
| C2a | 3.3µF | Aluminum Electrolytic | 3.3µF |
| C2b | 3.3µF | Aluminum Electrolytic | 3.3µF |
| C3 | 10µF | Aluminum Electrolytic | 10µF |
| C4 | 0.047µF | Ceramic or Film | 473 |
| C5 | 470pF | Ceramic | 471 or 470 |
| C6 | 470pF | Ceramic | 471 or 470 |
| C7 | 0.022µF | Film | 223 |
| C8a | 10µF | Aluminum Electrolytic | 10µF |
| C8b | 0.1µF | Film | 104 |
| C9 | 0.001µF | Ceramic or Film | 102 or 1n |
| C10 | 0.1µF | Film | 104 |
| C11 | 0.001µF | Ceramic or Film | 102 or 1n |
| C12 | 0.0047µF | Ceramic or Film | 472 or 4n7 |
| C13a | 500pF | Ceramic | 501 or 500 |
| C13b Potentiometers | 30pF Part Id | Ceramic | 30 Value |
| R13 | 50k Trimmer | ||
| R14 (Drive) | 500k linear | ||
| R15 (Tone) | 50k linear | ||
| R16 (Volume) | 100k log |
Other
| Part ID | Part Name |
|---|---|
| D1 | 1N914 |
| D2 | 12 volt Zener |
| Q1 | BS170 MOSFET Transistor |
| Q2 | 2N5457 (or J201) JFET Transistor |
| J1 | Stereo quarter-inch jack |
| J2 | Mono quarter-inch jack |
| J3 | DC Jack |
| B1 | 9 volt battery (not included in the Kit) |
| Sw1 | Heavy Duty 3PDT footswitch (bypass) |
| Sw2 | SPST or DPST mini toggle switch 9v battery snap, Printed Circuit Board, 24 gauge stranded wire, knobs enclosure |
How to build it
Instructions
Version 2015July01 · Copyright 2015 JD Sleep · Permission refused for posting/serving this file from any site other than www.generalguitargadgets.com · Trademarks are property of their owners
The Blue Star is a low to medium grit, tube-like overdrive pedal that is based on a MOSFET (BS170) pushing a JFET (J201) into distortion. The distortion range is about the same as an Ibanez™ Tube Screamer™, but the sound is better, more tubeamp-like response. Follow the General Building Instructions. Voltage at the JFET Drain should be about 4.7 volts, but tune it by ear with the trimmer. Modifications: R11 smooths out the sound, but at the cost of sounding less “open.” Thus, reduce R11 for a more open sound. You could switch in reduced resistance for R11 by switching in a parallel resistor.
More about this project
Notes, sounds and related links
Here are some sound samples of the Blue Star. These samples are of a Fender™ Stratocaster™ into the Blue Star Overdrive.
Ready to build? We have the kit.
Buy a Blue Star Complete Kit. Includes all the parts and materials you need to build one, all for about the price you would pay for a PCB and parts.
Would you like a Ready to Solder Circuit Board for this project?