speaker to amp

[mingmong30]

Hi, i am building a bartop arcade and ive come to a standstill as i have no idea what i am doing with the speakers and amplifier i have, could someone please help me as i have no idea where any wires go. I have included a ettachment of the amp that i have and its pretty basic, also ive read that the amp requires 12volts and that a yellow wire from a spare molex wud give me the 12volts required, thank you for reading

[lilshawn]

do you have a name/part number of the amp, it would really help to be able to look at the instructions or datasheet. what are you hooking this up to?

basically you are going to want  hack off a headphone plug or obtain a headphone plug somehow (i would guess you want to plug into a computer) and wire it to the input... the left and right signals (the wires inside of the core of the wire) go to the signal and the outside shielding goes to the ground.


and wire your speakers to the output... depending on the amps capabilities and the speaker ratings you are going to have to hook them up differently depending on that info. if the amp can do 4 ohms and you have 2 - 4 ohm speakers, you will have to wire them in series (positive from amp to positive on speaker1  and negative on speaker1  to positive on speaker2 and negative on speaker2 to negative on amp) because if you don't you'll blow the amp.

power is yellow and a black wire from your computer. (yellow is +12 volts and black is ground.) 

[mingmong30]

thank you for your reply, well its my 1st build so i didnt really know what i was buying lol i dont knw the brand or make of the amp, i bought it from
http://www.arcadeworlduk.com/products/Arcade-Speaker-Amplifier-With-PCB-Feet.html

And i bought these speakers to go with it from the same site
http://www.arcadeworlduk.com/products/4-Inch-8-Ohms-5-Watt-Speaker.html

i understood most of that, just not the end lol thank you again for your help 

[lilshawn]

what you really need to determine is what kind of speaker load it can handle.

hopefully you got an instruction manual with it. You want to find the rating. it will say something like 5watts at 4 ohms 2.5 watts at 8 ohms...something like that.

failing that, take a look at the chip mounted to the heatsink and post up the #'s on it. the datasheet for the chip will outline what kind of rating it has.

[mingmong30]

thank you, i got the speakers workig thanks to the advice from you, but i have a constant crackle all the time, even when there is no sound, can this be fixed? thanks, is it cos i am using a molex rather then its own power suply? thank you

[lilshawn]

it shouldn't need it's own supply. perhaps you are just picking up noise from someplace. try locating the amp somewhere else. failing that, i did have an amp powered by a computer one time and could hear every time the computer accessed the hard drive. i ended up having to power it separately.

also you need to still check that amplifier rating (or post the chip# (LM3886 etc.)) improperly loaded amp can do all kinds of unpredictable things if it's expecting 4 ohms worth of speakers and you have 16 hooked up to it.

try hooking the speakers up in parallel (a positive from each speaker running to the amp and a negative from each speaker to the amp) instead of daisy chaining in series. maybe the load is too high and needs to be brought down.

sorry if my post is all over i'm just sort of thinking out loud as i type it out.

[mingmong30]

Hi, thanks again. I just wired up 1 speaker at a time cos no matter how hard i looked i couldnt find anywhere were it told me the specs of the amp, i did find this most http://forum.arcadecontrols.com/index.php?topic=132304.0 and someone else had same product.

Also i am using the end molex from a string of daisy chained molex just so i can move the amp further away from psu, cud that affect it too also? thanks again

I seen some amazing custom arcades on here which made me wanna build 1, dont knw y i thought i was capable of building 1 when i even struggle to make a paper aeroplane lol :/


EDIT

Thanks

Right i cut sons portable dvd player 12v power supply up cos the buzzing was doing my head in, anyway the buzzing is slightly better but still annoying, i was concidering buying a new amp http://www.arcadeworlduk.com/products/22-Watt-Stereo-MOSFET-Sound-Amplifier.html to see if this solves the noise issue, am i likley wasting money by buying a different amp? just this 1 comes with its own power supply

thanks