(DIY) Class D Amplifier/booster

Knocked up this little Class D amp a few weeks back..



Parts list for anyone wanting to build.

7805 +5V 1A Voltage Regulator
6.5mm Stereo RIGHT ANGLE Plug
6.5mm Stereo INSULATED UNSWITCHED Socket
10uF 16V RB Electrolytic Capacitor - 105oC x2
Prototype board to mount Regulator and Caps (ebay)
PAM8403 Class D Amp (with or without Potentiometer) (ebay)
Safety 9V Battery Clip
Black Push On Style Knob
LED 3mm Red Diffused 40mcd (for power indicator)
450 Ohm Resistor to prevent LED burning itself out..
Jiffy Box - Black - 83 x 54 x 31mm
Pro Audio Speaker Cable 1m
DPDT Toggle switch (for battery cutoff)

These are easily adapted to 4 pin (SD-GP) also 5 pin (GPX) you will no longer need the 9v battery if you do this.
If you need any help/info I'll draw up some diagrams. but its pretty simple.

Awesome volume range on a 3w 8ohm speaker form miners den..
Headphone WARNING!!! If you build it and max the volume you may damage your hearing. BE SMART!!

Nice I'd like to give it a go, do you have a schematic diagram for it to show how it all hangs together?

I'll draw something up, and post it later tonight..

Thanks for that, greatly appreciated. It looks fairly straight forward but would hate to burn out the Amp circuit board by crossing the wrong wires. Not that I've ever done that before... :8

5 volt regulator required as the amp can't handle more than 5.5 volts.
Toggle switch is required because the regulator does its job while power is connected.

hey mate can you tell me if the F1A4 is stereo or mono?

Mono..

Basically, it has 4 wires coming off the PCB for headphones,

Red Blue Yellow Black.

Red is a switching circuit wire (positive)
Blue is the switching circuit connection also (positive)
Black is your ground..
Yellow is an amplified signal for shoulders speaker..

I use a 3 pin stereo plug.

Red is the last pin, blue to the middle, and black to shield.

when headphones are connected red and blue are shorted together by your headphones or speaker shutting off the internal speaker..

If you're talking about the original headphone connector, its basically a mono setup that can be easily rewired..

ok thank you.
my concern was that the head phones i have use a stereo plug.
and the speaker system i just got has a mono. i was worried i may lose 1 side of the signal or similar.
i wish this was here a week ago i would of done this. can a speaker b added to this??

What do you mean by a speaker be added?

like the treasure mate II.
it has a speaker and headphone jack.

You could do that i guess.

I installed one of the amplifiers in a pair of cheap RPG headphones just to see if it could be done, it can, it works but one slip on the volume knob and you're going to be deaf for a while..

I'm planning on buying a couple small(ish) speaker units, and install an amplifier in them, much like the Treasure mate.. the tricky part is finding a speaker+case the correct size, i'm thinking about a CB radio speaker..

will post some pix once i get it built.

Awesome downhalo, thats for that it is greatly appreciated.

New Micro amp board, should allow me to fit them into speakers such as the one sold by miners den, not sure if the 9v will fit too lol.. might need to find a slightly larger speaker.

the gme speakers for cb,s look ok just don't have a belt clip on them. though these can be put on later with good double sided tape.
could maybe run the battery online in its own little housing and the on off switch in it.

I've ordered a couple different speakers, I'll replace the internal speaker with something smaller and better quality.. hopefully it will all fit.

Look forward to the build Downhalo, appreciate the info and I wish there was more info like this around so we can try a few things with our machines. Well done.

Indeed, Unfortunately "Open Source" takes a back seat when douche bags can charge $1250 for "stuff"

Modified the build a little.. No longer using the 5v regulator, I've now switched to using 2x AAA batteries, without the regulator you will get a lot better battery life.. and no longer require the toggle switch..

these fit in the case..

http://www.ebay.com.au/itm/251545008820?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

Iv also build one a while ago but just wanted to add a few photo's just to give extra ideas.
Belt clip on the back and also back of EXT SPK.

Can use EXT SPK or headphones.

Ended up using 3x single AA holders. The EXT SPK is a hand held uhf Mic/SPK just with SPK wired up.

Awesome... I'm waiting on a shipment of slightly larger cases, mine are only 83x54x31mm only just enough space for a 9v or 2x AAA...