lm 3886 amp and testing pre-amp

[madapj]

hi everyone...

I'm going to build a lm3886 amp, homemade PCB.
I've already done one for the PC system and i have to said that sound really good.
I saw that a lot of people use the chipamp.com kit.
So i wanna use, for the project, all the definitions that they suggest for the kit, like the components value. They are incredible clean and good about the construction and everything else!!!
But my question is if that schematic, especially the values of the components, is the better choise for a guitar-amp.
i've read some post where is said to change some resistor value but i didn't understand well!!!
I don't have also problem to change the schematic, because i repeat, is homemade PCB.

Another quick question, about the preamp-section. maybe more important.

For now i need only an EASY and VERY CLEAN circuit, just said, only to test the amp.
I read a lot of tread "the better preamp for the gainclone" but, i know, there's no better, is only "which sound are you looking for" question, but i repeat, i need only an easy circuit to test the amp, maybe without extra noise and effects, like disorsion and so on!
I saw a lot of suggestion in here, but i think is not what i'm looking for.

So, any suggestions?

P.S: sorry for my english, i'm italian... i wrote as better as i could!!!

Thankyou to everyone answering me back!!!

Marco


 

[joecool85]

For just testing you can run it without a preamp at all, you just won't get full volume out of it.

[madapj]

yes, i know that, but i wanna know if there is a simple pre just to make the signal from the pickup in the right livel for the amp. thank anyway for the interesting.
Maybe something like a single opamp, two transistor... i don't know.
Anyway...

For the amp section:
In the schematic from the chipamp: what i have to do with the trimmer, i don't need it, i have to put a resistor instead? maybe a 22K to groung?
Here the link to the pdf presentation:
http://www.chipamp.com/docs/lm3886-manual.pdf.

I'm also asking if there are some modification that i can do to improve the sound.
I read somewhere that is better change some resistor value.... is this correct?
There are someone in here that have to some modification and can tell me which is the best way to choose the better sch for this LM3886? Any suggestion?
I have to use the optional cap named Ci (47uF)?

thank....

[phatt]

Hi madapj,
              Please note the error on the link.
Page 4 schematic 1/3 (The PSU)
I have not read it all but this one seemed rather obvious,
The negitive rail as drawn is back to front and
WILL lead to confusion for those starting out.

I believe it should look like this, see pic.

The 47uf cap sets the roll off for low frequency,, try between 5uF and 10uF.
50uF will only be needed for bass guitar, or disco doof.

http://www.ssguitar.com/index.php?topic=1136.0
If you want a preamp with no distortion,, and it will then actually sound like a guitar amplifier.
Phil.