Project · Direct To Console
Marshall™-Type Speaker Simulator
This project is a replica of a circuit found in some Marshall™ Amps that precedes the direct-out on the amp to provide some speaker simulation. It is a fantastic sounding and easy to build speaker simulator. It could be a valuable addition to your direct output.
Project files
Everything you need to build it
Marshall™ Speaker Sim 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.
Parts layout
Parts Layout / Wiring Diagram
What you will need
Bill of Materials
Version 2019May21 · Copyright 2017 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 | 27k | red-violet-orange | red-violet-black-red |
| R2 | 47k | yellow-violet-orange | yellow-violet-black-red |
| R3 | 33k | orange-orange-orange | orange-orange-black-red |
| R4 | 4k7 (4.7k) | yellow-violet-red | yellow-violet-black-brown |
| R5 | 100k | brown-black-yellow | brown-black-black-orange |
| R6 | 47k | yellow-violet-orange | yellow-violet-black-red |
| R7 | 470k | yellow-violet-yellow | yellow-violet-black-orange |
| R8 | 1M | brown-black-green | brown-black-black-yellow |
| R9 | 12k | brown-red-orange | brown-red-black-red |
| R10 | 10k | brown-black-orange | brown-black-black-red |
| R11 | 12k | brown-red-orange | brown-red-black-red |
| R12 | 10k | brown-black-orange | brown-black-black-red |
| R13 | 10k | brown-black-orange | brown-black-black-red |
| R14 | 10k | brown-black-orange | brown-black-black-red |
| R15 | 1k | brown-black-red | brown-black-black-brown |
Capacitors
| Capacitor ID | Value | Type | Possible Marking |
|---|---|---|---|
| C1 | 0.047µF | Film | 473 |
| C2 | 0.0033µF | Film or Ceramic | 332 |
| C3 | 0.068µF | Film | 683 |
| C4 | 0.1µF | FIlm | 104 |
| C5 | 100pF | Ceramic | 101 |
| C6 | 0.01µF | FIlm | 103 |
| C7 | 0.0001µF | Film or Ceramic | 102 |
| C8 | 0.0047µF | Film or Ceramic | 473 |
| C9 | 0.0022µF | Film or Ceramic | 223 |
| C10 | 47µF | Aluminum Electrolytic | 47µF |
| C11 | 47µF | Aluminum Electrolytic | 47µF |
Other
| Part ID | Part Name |
|---|---|
| IC1 | TL072 Opamp |
| IC2 | TL072 Opamp |
| 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 9v battery snap, Printed Circuit Board, 24 gauge stranded wire, Enclosure, Knobs |
How to build it
Instructions
Version 2017October29 · Copyright 2017 JD Sleep · Permission refused for posting/serving this file from any site other than www.generalguitargadgets.com · Trademarks are property of their owners
This is a circuit from a Marshall™ amp that provide a “speaker simulation” sound to the direct out of the amplifier. This is an awesome circuit to run from your signal to a direct box. Use the project documents provided, starting with the General Build Instructions. This is a fairly simple build since there are no knobs and you don’t need the foot switch and LED. We added the bypass foot switch so that we could test it, A/B the sound with and without the simulator.
Here's an inside view of the unit we built to show our construction details..
Comments and questions are welcome and can be sent to [email protected]
More about this project
Notes, sounds and related links
Ready to build? We have the kit.
Would you like a Ready to Solder Circuit Board for this project?