NEW 400 WATT KOAC LITMITED EDITION CAR AMP AMPLIFIER SCAM, FRAUD

as currently being offered on Ebay. (September 2007)

My guess is that some folks send their feedback immmediately they receive the item - and perhaps regret it later. Others just don't want to risk the neg FB and shrug it off as a lesson learned. Maybe I should too but I think it's wrong that Ebay should allow this kind of trade to continue.

This amplifier is supplied without a single scrap of documentation
Hence the warning below about an inline power fuse.

Here's a view of the inside. The black chip at the top is the entire 'amplifier'. It's just 36mm wide. The other few components are resistors and capacitors which support the chip.

The chip is made by Toshiba and is probably intended as the output amplifier for inexpensive car radios. Toshiba, on their website, rate the amplifier at 22watts per channel into a 4ohm load with 14.4volts applied. AT 10% distortion! My guess is that 5 watts per channel might give acceptable distortion.
The data sheet can be examined here:

The data sheet goes on to state that a good distortion figure, (.o4%) is achieved at 1watt output !

There is no fuse in this amplifier and it would be foolhardy not to include one in the supply line. If anyone were to connect it up and attempt to screw the sort of power they expect the chip would fry. With no fuse the supply wire might burn up causing a fire or it could pass 12v to their valuable speakers and fry them.(even with a fuse this could happen)

Another warning..

Running an ampifier with too low an output power (for that expected) can cause the amplier to clip. This is another good way to fry a loudspeakers . The amplifier is probably ok for use at low power - perhaps a guitar practice amp, intercom etc. It might make a reasonable headhone amp.

My own buying experience.

The seller shipped the item promptly - It came in about a week, including airmail from Hong Kong.

It was simply wrapped in paper and cost $83.3 (Hong Kong) to post. That's about £5 uk. The seller charges £12.99 so there's £8 profit on top of the minimum 99p it cost. Seller therefore got £9.24 in this case and is probably delighted with that. He had completed the Customs declaration, picture here, and declared it's value as $80 which is about £5. He also states that it's a toy! fairly accurate there then.

Inside the wrapping, the amp was in a box bearing two different model numbers: V3 and F3. THE FALSE CLAIMS ON EBAY ARE ACTUALLY PRINTED ON THE BOX- with more besides, so it's pretty obvious that it has been manufactured in the first instance especially to deceive.

Here is the item description from Ebay:

1) 400 Watts Max Output Power
2) 2 OHM Stable & TRI-MODE Connection Possible
3) 2 Channel 2 OHM Stable Multi-Channel Circuit Design
4) Thermal / Short-Circuit / Overloading Protection
5) High Efficiency MOSFET Power Supply
6)Variable Bass Booster
7) RCA Inputs & Speaker Terminals
8) Power On & Protection Led Indicators

The box adds:

9) Fan Cooling System
10) VU meter output level

!, 5, 6, 9 and 10 are simply not true!
8 is half true - there is no protection LED
2 and 3 - well Toshiba gives the output impedance as 4ohms. 2ohms will probably screw it.

YOU MUST ALSO SEE this interesting old Ebay listing!! from a fleeced buyer.