10w mini amp questions.

[Sengo]

Hello,

    I want to mess around with the 10w mini audio amp as a tiny guitar amp just for the hell of it. I was wondering what type of capacitors the 470nf and 100nf capacitors were. I read a webpage where a gentleman used one of the store bought audio amps to do this so I thought it would be a neat project.

Thanks,

Nick

 

[audioguru2]

Hi Nick,
Welcome to our forum. ;D
Use film capacitors for those two.
The TDA2003 IC won't give anything like 10W with only a 9V battery. It is spec'd to give 10W to a 2 ohm speaker with a 14.4V supply and clipping badly with 10% distortion.
A graph in its datasheet shows it producing 2.2W into a 4 ohm speaker with a 9V supply, clipping hard. It is probably only 1.5W just below clipping.

 

[Sengo]

Thanks audioguru,

    I ordered my parts and am just waiting for the 450nF cap to arrive. I started wiring it up and now I have a question about the 10K Pot. I don't have a schematic so I'm working from the PCB design given on the projects page. What I would like to know is the whiper on the pot wired to cap3 or to the input?

Please excuse my poor visual representation of my question.....

                  10K                                                10K
input + ----/\/\/\---- input -      -or-      cap3---/\/\/\---input-
                    ^                                                  ^
                    l                                                    l
                  cap3                                            input+

I've been reading some of the other topics on this forum and would just like to say this website is awesome, very informed and helpful people who don't mind explaining things to beginners.

Thanks,

Nick

 

[audioguru2]

I ordered my parts and am just waiting for the 450nF cap to arrive.

It doesn't use and there is no such thing as a 450nF cap. It needs 470nF for C3.

is the wiper on the pot wired to cap3 or to the input?

The project's layout sketch correctly shows the wiper of the pot connected to C3, and the ends of the pot connected to the input and to ground.View attachment 39472

 

[Sengo]

Cool,

    I mispoke about the cap I meant 470nf, heh. And thankyou for clearing up my problem with the pot. I was thinking the whiper was the pin that had no resistance change when turning the knob.

Nick

 

[audioguru2]

Hi Nick,
The wiper of a pot wipes from one end of its resistance to the other end.