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-   -   Counterfeit Amps? (https://www.diyaudio.com/forums/class-d/338835-counterfeit-amps.html)

AJ02 6th June 2019 08:11 PM

Counterfeit Amps?
 
I am looking to buy a alpine pdx v9, it is $850, but on amazon its $420, the downside is it isnt a authorized seller, but according to the reviews the amp works 100% and it seems legit. Im looking for your guys opinions

ICG 7th June 2019 12:14 AM

It is very rare a complete amp is faked. Cheap copys (which copy the circuit but are distinguishable), yes, faked chips, yes. A close to 1:1 fake? Unlikely since the manufacturer would very quickly notice it and intervene. Impossible? No, ofcourse not.

To check if that's a fake, look for similar offers or use price check websites. If there are no other offers near that price, it's probably too good to be true. For the Alpine PDX-V9, I've found instantly a lot offers from 619€ down to 385€, 5 between 390 and 460€. So a price of 420$ seems to be really reasonable, a fake is quite unlikely. To be more certain of it, check if the ratings were given from verified buyers.

E: You could pay with PayPal, that gives you buyer protection. Amazon pay got something similar but that does not apply to all sellers, I'm not sure how to recognize that though.

nigelwright7557 7th June 2019 01:21 AM

You pay your money and take your chances.
I tend to buy from reputable dealers now after buying lots of junk on ebay.
I have a long list of duff stuff I bought off ebay.
Transistors that lasted 10 minutes until first mains glitch.
Four power supplies that lasted about half an hour.
Four flash drives that took 3 months to arrive then none worked.
Disco lights that half of the bulbs didnt work.
etc etc

ICG 7th June 2019 02:17 AM

I've bought a lot, in fact, tons of stuff of ebay. The US, China, Germany and all over Europe. Yes, I had fakes, 2 times out of several hundreds orders. One of it were fake capacitors the other were amp boards with the TDA7294 instead of the TDA7293. The amp boards worked fine with my planned use nonetheless, both orders were covered by PayPal. Both times it was my own fault, if it looks too good to be true, it probably is.

Take these precautions to order (and probably some more):
  • Check if there are other sellers with similar prices. If there are just very few that cheap and the rest are much more expenxive or just one offer for that price, don't buy it.
  • Don't buy without buyer protection payment
  • Don't buy 'rare' semiconductors from China, check them for hints of a fake. Buy rather comparison types, replacements.
  • Buy only parts from etablished sellers.
  • Look very closely at the pictures. If the pictures are bad and/or hiding important parts, hands off. Try to identify problems (i.e. at drivers), analyze the pictures.
  • Search for the distinguished features of the item on print and contacts or housing. Compare to the datasheet of the manufacturer.
  • If it seems too good to be true, it probably is.
  • Don't be too greedy. Use common sense.
  • Remember the buyer payment protection? If it doesn't arrive in time, open a case. If it comes late, you can still close the case.
  • If you are unsure about an item, ask i.e. here in the forum.
  • Use common sense!

nigelwright7557 7th June 2019 02:25 AM

I don't even look at ebay for electronic components now.
The likes of RS Components and Farnell always supply excellent quality components.
And quite often the prices aren't too much above the fake stuff.

ICG 7th June 2019 02:57 AM

Yes, exactly. That bit 'more expensive' saves you so much trouble and potentially destroying other parts - that's just not worth it.

AJ02 7th June 2019 04:02 AM

I think the amp should be real honestly, there are a lot of good reviews on amazon and I spoke with an alpine rep and he said those amps arent really fake, its just that those people get a hold of them some how and they sell them when they aren't supposed to, and a lot of the prices on amazons from different sellers were similar, anyway ill post back once I receive the amp and show you guys whats comes in the box, if it comes in a brand new box with a birth sheet it should be fine. I dont think amazon sells a lot of fake stuff anyway.

Mark Tillotson 7th June 2019 12:44 PM

One thing I would advise is never buy cheap speaker wire, it will be dreaded CCA, not copper.

ICG 7th June 2019 04:11 PM

Quote:

Originally Posted by Mark Tillotson (https://www.diyaudio.com/forums/class-d/338835-counterfeit-amps-post5815452.html#post5815452)
One thing I would advise is never buy cheap speaker wire, it will be dreaded CCA, not copper.

CCA (Copper Clad Aluminium) isn't bad, depending on the use. Yes, it's a lot cheaper and it's not adequate for cables that are moved often (mobile PA i.e.). Copper is much better in flexibility and how often it may be bent, but much more expensive. The conductivity is also better but that does not actually matter for speaker wiring, the contact resistance is much, much worse. It should always be checked what kind of wire is actually used, most cables use CCA.

Mark Tillotson 8th June 2019 12:11 AM

Quote:

The conductivity is also better but that does not actually matter for speaker wiring
Well that's a contraversial statement.

CCA is a reliability problem, it may come loose over time from screw terminals due to thermal cycling, it will fail much sooner in a high vibration environment due to its relative brittleness, and it may start fires if someone is led to believe its copper and uses inadequately rated cable for high currents.

But my main objection is being defrauded when I've bought something ostensibly 4mm copper for high current wiring (for motors, not speakers in fact), and get this CCA crap instead.

Aluminium cabling is used a lot in industry as its cheaper, but they use the proper fittings for reliable connection, don't use it as flex, and don't pretend its something its not.


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