Newbie Guidance...

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oK, in reference to: http://hepso.dna.fi/misc/LM3886_amplifier.html

Intending to build this amp on the page linked below, but am confused what to do as far as the power supply. I really don't have any good experience with these DIY Audio Amps so as I read the page I caught onto the ideal behind the AMP but the page author was rather vague about how he provided a clean source of Direct-Current that the AMP needed.

So I am asking you what should I do. I hopefully should be able to figure out the rest if I can get my hands on the plans (schematics, parts list and all) for an acceptable power supply for this setup here that I want to build.

So if you could help me out by pointing me something that meets the requirements of the AMP I am intending to build and is reliable, I would greatly appreciate it.

Thank you.
 
Thanks again

I am down to the Tantalum Capacitors on the list, do those need to be high voltage like 50-80v? The most I see are 10v and such, I do see some reasonably priced 20v, 25 and 35v ones now but I am still not sure if these capacitors in particualr need to be able to handle high-voltage amounts.

Personally, I don't think they do, but I just wanted to ask.
 
I don't think you should be using tantalum capacitors in this circuit at all. Comparing schematic and parts list, it seems like he chooses 10u coupling cap and 100u cap (shunting inverting input) as tantalums. I wouldn't recommend it.

Why don't you base your circuit more on what National is suggesting? Although it says LM1875, it doesn't change for LM3886 (except for mute).
 

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Actually I was wondering why he would want to use tantulams...seems you could use BGs and stuff here and get better results...I would recommend he check Nuuk's pages for some sugestions while retaining the use of the 3886...whihc has high current capability then the 3875...but you still have the mute pin to worry about...I did build an 3886 amp only to wonder why there was no sound...then I realised I never connected anything to the mute pin...stupid me...
 
Well how does the mute pin work? I thought it muted the sound when grounded or when one would raise a + Signal to it.

See if the mute feature is out to get me then I won't get a chip with a mute feature.


Ugh.... Anyway, If I had to go with something that National Reccomends rather than following the plan layed out by the website, I would follow the 'Typical Application' schematic in the LM3886 datasheet:

http://www.national.com/ds/LM/LM3886.pdf

I'm sure it would work, it's just a matter of moving the schematic to Eagle and then designing the board :(
 
Sorry, for some reason I wasn't able to EDIT my last reply so i had to post another one here.

My problem with using that schematic right now is the fact that Eagle doesn't have the LM3886 CHIP in it's component library, let alone any equivilant that i know of (none). I am too sleepy and don't have the enthusiasm to make a custom chip, so I am asking for some advice what I should do.

I was thinking a second ago about doing it the Protoboard method but I believe with high voltage applications using protoboards for primary use isn't a good ideal - I don't want to hand-wire everything togethe like a ghetto rig either, I could do it that way, but I'd rathewr have something cleaner and more presentable...
 
I made the lm3875 part for eagle, if you want it let me know I''ll email you the library.

I have made amps out of both the 3886 and 3875 and prefer the 3875 over 3886 in quality of sound and the lack of the mute function. Over both of these though I would take an OPA541 any day, they are more expensive but are very enjoyable to listen to.

You can look at an amp I'm toying with currently http://www.easyamp.com/img/lm3875/amp-top.jpg
http://www.easyamp.com/img/lm3875/amp-bottom.jpg



The amps are on the same board but are independent. If you would like a schematic or parts list let me know.
 
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