LM3886*3 Amp ebay kit

[FOXYE]

Anyone know this amp kit?

LM3886*3 Amp + Power supper kit/DIY - eBay (item 320464946907 end time Nov-14-10 23:03:59 PST)

How good is it? And is the amp kit reliable?

[abraxalito]

Since the seller has put up his email address, why not request a schematic of the paralleled amp from him? Things to check are that close tolerance parts are used in the gain networks - there are trimmers on the board but those might be for offset trimming purposes. If the design is based on National's AN-1192 it might have problems. The price looks reasonable given the 1off price of LM3886 is around $7.

[tangmonster]

i have used the bare pcb's from the seller in my build.

the schematic looks like this one:

DIY BPA300 6x LM3886 300W audio Amplifier

i would however not trust the gain and feedback resistors and if you buy the complete kit change them out with decent 0.1% items.

also i felt that C2 capacitor(as per link schematic) was far to big a size and would cut into audio spectrum. You can change these to around 10pF.

Without those 3 capacitors the board immediately oscillated i found in my testing. and made the zobel resistor smoke

[FOXYE]

Here the schematic

http://img574.imageshack.us/img574/3301/111el.jpg

[tangmonster]

On your schematic I was talking about:

R1 , r4 , r10 and r3 , r6, r12

i was also talking about

c4 , c6 , c11

[frank1]

Originally Posted by FOXYE

Anyone know this amp kit?

LM3886*3 Amp + Power supper kit/DIY - eBay (item 320464946907 end time Nov-14-10 23:03:59 PST)

How good is it? And is the amp kit reliable?

I think this is the seller I had a problem with.

I ordered several LM3886 and power supply PCB's to make 2x 5-channel amps.
None of them worked at first...
There was no through-hole plating on one end of C7 (the input cap).
I tried complaining but couldn't get my message through - Language problem!!!
Gave up in the end and just soldered the lead both sides.
The boards were good quality apart from that. I can't beleive no-one else noticed
Frank