The Macamp - The personal sound amplification device

In this instructable, I am going to show you how to make a personal amplifier from near scratch.
I put mine inside a macintosh 7200 casing because of it's size, and how easy it would be to work with.
materials:
1x pc motherboard
1x casing
1x power supply
1x cd-rom drive
unlimited lights
2x power switch
unlimited fans
2x dollar store "Spy Ears"
wire
1x speaker

Grab your tools, and let's get started!

(sorry for the blurry photos, i have a bad camera)

Step 1 Find a case and gut it

I chose a powermac 7200 case, because it is a quite large case, and i already had one laying around.

You are going to need to completely empty the case, Be sure to remove everything, being careful to not break the plastic, it will most likely be very brittle from so many years of age.

Also remember to unplug everything, or you might run into trouble along the way.

Comments

[mulluysavage]

okay i think i figured part of it out - i just had the 1.5v battery in there. I hooked it up to a 9V, and it puts out a lot more sound, but it sounds like crap - totally distorted, no matter what combo of volume between the ipod and the spy ears.

[zack247]

are you using the same speaker? try using one with a higher ohm count, you will probably get a better sound quality than with a speaker with a lower count

[mulluysavage]

it's not distorted at the combo you reccomend - all the way up on the amp, really low on the mp3. but it's quieter than a headphone.

[zack247]

i said 3/4 on the mp3. loud, but not so loud you are overloading the amp and just getting fuzz

[mulluysavage]

anything over 1/10th loud is way distorted. I'm using an 1/8" plug connected to the mic leads with alligator clips.

[zack247]

ok.
1: what mp3 player are you using?
2: try turning down the amp, you may get better results.
3: try putting a capacitor between audio out and the speaker. (4.7 or 47 uF should work)
 

[mulluysavage]

i hooked up a spy ear amp to a 3" 8ohm speaker and then used an mp3 player as an input into the spy ear mic - and it doesn't seem to me to put out alot of sound, in fact, it's pretty much like a headphone. What am I doing wrong?

[zack247]

first of all, how much power do you have going into this? i have 12v in mine, so a 9v battery would work fine.
second, did you connect a audio jack to the mics wires? or did you do it some other way?
the smaller the speaker, the worse the sound is. the speaker is used was a 16 ohm one, and the sound is considerably loud.
if none of this works, post back and ill see what else might be wrong.
i read somewhere that you can remove the fuzz by adding a capacitor on the audio out line. im not sure how, but im sure there is an instructable somewhere here that'll help!

good luck!

[mulluysavage]

I'm having trouble figuring out why you are using 2 spy ears.

[zack247]

i have 1 for the cd drive, and 1 for the external sound input.

[GreenD]

 This is awesome, in theory this should just be as easy with more up to date dells and other computers right?? I shall be looking at my home dead computer for surely! :)

[zack247]

yep. i just chose the mac for its case and the motherboard that was in it didn't suit my needs. but yes, you could use newer computers, and make sure your power supply has a value of more than 250w, or else you will be having the trouble i am, with all the lights, it'll sometimes turn off

[cowscankill]

Very cool. Problem for me is acquiring speakers.

[zack247]

speakers can be aquired from just about anywhere. the speakers from old pc's would work too. they're still speakers, right?

[cowscankill]

Meh... unless you break them ;_;
Well, I guess I shall continue my search.  Thanks greatly for the tip about the amplifier, I have one of those toys.

[zack247]

and the best part is, they only cost about $1 to get! i wasreally surprised about how loud those things can get. i really hate the mic feedback though. but you know what? i put 12 vots through that thing and it still hasn't blown up yet!

[cowscankill]

Hmmm.... idea! I could put two computer speakers in to a box with an Spy Ear to amp it up for portable use with my mp3 player! Would it work if battery powered? I think so... if not I will design a power budget.

[zack247]

hey, its battery powered to start with, isn't it? and you could put a 9v battery in there and still do no harm. much easier than making the amp from a cd drive or from scratch. perhaps i should make an instructable...

[TheCheese9921]

Could you post a video of your results?

[zack247]

if I can find a good camera, I will