Picture of Surround Sound from 3.5 mm stereo
CD source.JPG
Tape source.JPG
MP3 source.JPG
This Instructable describes how I built a surround sound system for use with a 3.5 mm stereo output. The goal is to extend surround sound experience from any 3.5 mm stereo headphone output with quality and simplicity. Works great with PCs, MP3 players, CD players, tape recorders etc. This is a low power (around 1 Watt) version of the ABC surround sound decoder.

You will need the following items to build 3.5 mm surround sound:
- Parts shown on attached schematic.
- Plugboard.
- 4 heatsinks (1.5" x 2" copper or aluminum sheet metal).
- 4 speakers (4 - 8 Ohm, about 3 Watt nominal power). Almost any type of speaker works:
Computer speakers, satellite speakers, small speakers, big speakers, etc.
- Wire.
- 4 phillips 6-32X1/4 nylon machine screws.
- 4 nylon 6-32 hex nuts.
- Heatsink grease.
- 12V, 500mA or more power supply.
- 3.5 mm plug to 3.5 mm plug cable.

Drill, solder gun and soldering accessories, cutters, tweezers, wirestripper.

Step 1: Making the circuit

Picture of Making the circuit
Bottom view.JPG
Front view.JPG
The circuit I used consists of a power amplifier with 3.5 mm jack input and the surround sound decoder. 3.5 mm input jack can be replaced by cable with 3.5 mm plug if desired.

Mark future hole center by placing T3 transistor at lower left corner of the heatsink. Drill hole in each heatsink.

Assemble circuit shown on schematic. This step requires some assembling and testing skills.

Apply a small amount of heatsink grease on T3, T4, T7, T8 transistors and secure heatsink on each of them using screw and nut. Warning: heatsinks should not touch each other!

3_5 mm ABC.pdf(792x1224) 37 KB
jaxboy3 years ago
You can add a center channel simply by running a wire from the + terminal of the 2 stereo speakers to the terminals of the center channel speaker. It results in only a slight reduction of volume, but true center channel output.
DustySeven73 years ago
This is not really surround sound. Surround sound is 4 distinctive and different channels. This is surround stereo. Stereo sound that is duplicated to front and side channels
i-blaze3 years ago
will dis work with 5.1 headphones
Rahul164 years ago
Can u provide detailed component list used in making the amplifier and decoder. you have used to one more socket, for connecting speakers. can u tell in detail how u connected the other speaker with out socket(soldered wire). because i too have same type speakers one set with jack and another without jack.
wobbler5 years ago
This looks like it a slightly more complicated version of the Hafler circuit: http://members.tripod.com/martin_leese/Audio/HaflerCircuit.txt The Hafler system can easily be added to a two speaker system with its own amp using a pair of old speakers. leaving out the front centre speaker. I'd be interested in comparing the two eventually. You can see it here in another post too: http://www.instructables.com/id/Surround-sound-for-free-it-could-save-your-marria/ Keep on truckin'!
 Can i mod my 2.1 for this?
RRC (author)  HADJISTYLLIS5 years ago
Feed left and right channels into ABC decoder to get four outs, leave subwoofer as is.
thanks its going to be great
Why do people leave the product stickers on laptops and lcd displays? I know I'm a little off topic but it bugs me :p Anyway, great 'ible.
RRC (author)  Marble of Doom5 years ago
This laptop belongs to lab, no one cares about lables as long as it does the job.
tigerdog3306 years ago
is there any way to mod the circuit to have center and subwoofer outs too?
RRC (author)  tigerdog3306 years ago
Center speaker is not part of this concept. Sudwoofer can be pulled out from any front speaker via crossover network.
tigerdog330 RRC6 years ago
ok sounds good thanks.. ill probably be doing this i my basement now
SRChiP6 years ago
What's the output wattage of the speaker? Can you use the ABC decorder part for a regular stereo amplifier?
RRC (author)  SRChiP6 years ago
0.5 W and up will work well with this option, wattage is limited by amplifier's output power and ABC decoder power dissipation. I'm using ABC decoder with regular stereo amplifier for many years and recently with stereo output of Plasma TV.
SRChiP RRC6 years ago
Thanks, but what is the approx. output of the stereo amplifier per channel?
RRC (author)  SRChiP6 years ago
I designed it to deliver 1W per channel.
SRChiP RRC6 years ago
RRC (author) 6 years ago
I'm working on USB Surround Sound - ideal for computers.