Is this a good LM3886 Kit?

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yeah it's dirt cheap, they obviously do not use original parts, but they do buy in large QTYs so it would be much cheaper than buying 2 from digikey. besides based on seller notes they use pulled components from torn down units :
An externally hosted image should be here but it was not working when we last tested it.


well at least they are honest about it !.
keep in mind that replacing the original caps with Audyn did make a huge different.

I do not have any equipment to measure anything, but compare to my Yamaha amp ( my reference amp ) it has slightly warmer character which i like.
 
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yeah it's dirt cheap, they obviously do not use original parts, but they do buy in large QTYs so it would be much cheaper than buying 2 from digikey.

You're still looking at $7.25 for two LM3886TF at QTY = 1000 on Digikey.

I simply don't get the idea of buying projects that include fake parts, even if you can swap all the components out with known good components. There's more to good circuit layout than connecting the dots.

Tom
 
Do we actually know that any of these parts are fake?
1) whenever I've spec'd components, a decent purchasing person in a small- mid size electronics company has been able to get them for a fraction of the Mouser/RS/Farnell 100-off price.
2) These Chinese outfits seem to be able to sell things at a loss to generate USD/euro/GBP revenue?
3) Don't forget that they are playing games with duties/sales tax/tarrifs by selling under the threshold where the taxman takes an interest.
4) I think some of these things are designed to use up remainder stock from assembly houses. Somebody buys a few thousand chips left over at the end of a run and knocks them out as a kit?

I know there is fake stuff out there, but is it really worth the effort to fake a part that's a dollar at the factory gate?
Anyone ever seen a proven fake chip? from an ebay kit?

I dare say a few dies go out the back door from 'outsource' fabs but AIUI, most of these get passed off as 'second source' alternatives.

It's not like say memory chips where it's viable to re-badge slow stuff as fast stuff or whatever.

The other thing is, these kits are part of many people's learning curve. You don't understand good PCB layout until you've suffered bad PCB layout.
( I assume that's tre in audio as it is in other areas of electronics?)
 
Yeah, sorta makes you wonder, though----torn down FROM WHAT?
from returned or "not working" and outdated units, this is what we do at our company with computer parts, and you won't believe the stuff we receive as faulty or damaged ! sometimes even brand new working components.

You're still looking at $7.25 for two LM3886TF at QTY = 1000 on Digikey.

never said they are fake or not, neither takin anybody's side,.

Do we actually know that any of these parts are fake?
1) whenever I've spec'd components, a decent purchasing person in a small- mid size electronics company has been able to get them for a fraction of the Mouser/RS/Farnell 100-off price.
2) These Chinese outfits seem to be able to sell things at a loss to generate USD/euro/GBP revenue?
3) Don't forget that they are playing games with duties/sales tax/tarrifs by selling under the threshold where the taxman takes an interest.
4) I think some of these things are designed to use up remainder stock from assembly houses. Somebody buys a few thousand chips left over at the end of a run and knocks them out as a kit?

I know there is fake stuff out there, but is it really worth the effort to fake a part that's a dollar at the factory gate?
Anyone ever seen a proven fake chip? from an ebay kit?

I dare say a few dies go out the back door from 'outsource' fabs but AIUI, most of these get passed off as 'second source' alternatives.

It's not like say memory chips where it's viable to re-badge slow stuff as fast stuff or whatever.

The other thing is, these kits are part of many people's learning curve. You don't understand good PCB layout until you've suffered bad PCB layout.
( I assume that's tre in audio as it is in other areas of electronics?)

couldn't agree more, people focus way too much on what's fake or what and i bet that if you do a blind test 90% wouldn't be able to tell.

i do not call myself audiophile or a pro or whatever, i just don't hear anything horribly wrong and i m happy with it !
 
You don't understand good PCB layout until you've suffered bad PCB layout.

I'd say you don't understand good layout until you understand Ohm's Law and perhaps a little electromagnetic field theory and can apply those to your circuit. If you want the best performance, you'll need to have some experience with precision circuit design as well.

Tom
 
I simply don't get the idea of buying projects that include fake parts, even if you can swap all the components out with known good components. There's more to good circuit layout than connecting the dots.
Tom
Well, the idea is quite simple...If you are building a say, 4-channel amp (stereo bi amp), the eBay kits cost ~$32. If you go the neurochrome route, you're at $300 JUST FOR THE BARE BOARDS AND PLANS. Now, paying extra for a superior design is all well, and good. But an extra $260 (say the boards are $20 apiece) is HIGHWAY ROBBERY!! HALF that would be a steep price---maybe worth it.
 

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Is the mounting tab connected to one of the power rails on those chips? Whats most important is that the heatsink isn't floating, so that would be ok so long as it doesn't make contact with the chassis. It's usually safer and simpler to isolate the chip from the heatsink with a mica washer or silicon pad designed for the purpose
 
Is the mounting tab connected to one of the power rails on those chips? Whats most important is that the heatsink isn't floating, so that would be ok so long as it doesn't make contact with the chassis. It's usually safer and simpler to isolate the chip from the heatsink with a mica washer or silicon pad designed for the purpose
At the moment Im durectly bolted through the chip eyelet with a 3mm bolt into the heatsink that is drilled and tapped. So the chip is hard mounted to the heatsink with no insulation and heatsink is floating at the moment.
So should I just bolt a wire to the heatsink and run it to the earth shared point or find some of these magic pads you speak of. Or should I do both? Thanks
 
Measure the resistance between the -V pin on the chips and the mounting bolt. Is the mounting tab plastic or metal? TF looks like the isolated one. If that's the case run a wire from the heatsink to the shared earth. What kind of noise are you getting and what's the source?
 
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