[FONT=Arial, Helvetica, sans-serif] Here we have a new and boxed KOAC amplifier optimistically rated at 400 Watts according to the labels.

Only taken out of the box to see what it looks like up close, never fitted to a vehicle or connected to power

So lets have a little look inside this supposed boombox powerhouse, lets see what secret weapon it uses to fit so much power in so little space.



[/FONT][FONT=Arial, Helvetica, sans-serif] WoW!
Not a lot in there to be honest, a few pence worth of passive components and some rather skinny interconnect wiring for a bowel churning 400 watts of quality audio.

In fact theres only ONE active component in there, held against the case by a couple of Meccano bolts. No anti-rattle washers or threadlock on the screws but then stuff in cars doesn't get much in the way of vibration to deal with unless they are being driven about.
Sitting in Maccy D's car park for hours at a time probably wont shake anything loose.

Look closer I hear you say, how do they get 400w watts from so little?



[/FONT][FONT=Arial, Helvetica, sans-serif] That chip has a Toshiba part number, lets dig out the datasheet and see if theres actually more than 400W available.

[/FONT]http://www.toshiba.com/taec/components/D...HQ_ALQ.pdf
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So its really a single chip 20W two channel amplifier, 22W if you like 10% distortion
How can this be?

Look its even got a Mercedes Vision Roadster on the box so there must be an element of quality to it.



[/FONT][FONT=Arial, Helvetica, sans-serif] OK, enough pretence, lets get down to a real description of this item

Its a chinese $5 amplifier that gets advertised as being in the UK with £15 postage to make you think its a heavy weight amplifier when its actually posted from Hong Kong.
Its not, nor will it ever be capable of 400w and would be more suited as a headphone amplifier for an elderly relative suffering from hearing loss or perhaps playing Agadoo at the scouts disco with no possibility of annoying the neighbours.

Ebay is brimming with these amps, in much the same way as a Glastonbury portaloo brims,

So be aware ppl.


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Just for reference...

Heres what a proper amp should look like inside

Lol, Good Rant Ste, Thanks for Info =D

you can see all the stuff in my amp! rate good!

thats aloud of shit

My amp = Resonant Engineering 12.1




ALL UNDER-RATED SPEC but...

400WRMS @ 4 Ohms
800WRMS @ 2 Ohms
1200WRMS @ 1 Ohm

However they have been known to be puting out 1600WRMS @ 1 Ohm.

*Pics not took by me!

They probly worked out the power of the IC using 20W RMS which is about 57W Peak (20/0.707) which equals 114W Peak to Peak (57+57) into a 4ohm load so using ohms law to work out the power output into a 1ohm load you get a whopping 456W of pure distorted shite and a fireball in your boot

Oh and these calculations are for a perfect world where there is no energy loss from poor quality components and heat disipation. Maybe you need to a fridge running at 0 kelvin in your boot to achieve 400 watts

lol i love them amps i have 1 it holds the bedroom door open (was given it)

i had 10 of these in my nova and got a reading of 160.2dB

i had 10 of these in my nova and got a reading of 160.2dB

You fibber

ok 159Db

you could do with one of these in your bummer to drown out the noise of your gearbox then