A plug and jack that use 3 wires for tip, ring and sleeve are for stereo. With mono then usually 2 wires plugs and jacks are used that have only tip and sleeve.

Since you have the wrong plug and jack for mono then connect the signal wire to the tip, connect the (grounded) shield wire to the sleeve and connect nothing to the ring.

Exactly in that way I have connected them.

The problem is that when I stick the jack in the plug I hear a bad noise with no music, but when I let the jack half sticked in the plug the music is playng.

I had switched the wire connected to the tip, to the Ring, ( I presumed that it will be working, but I was wrong).

I can't get where is the problem!?!

 

Perhaps you have the ground connected to the ring instead of the sleeve? You would then lose the ground connection with the plug fully inserted. That would be likely to give you mains field induced buzzing.

 

Perhaps you have the ground connected to the ring instead of the sleeve? You would then lose the ground connection with the plug fully inserted. That would be likely to give you mains field induced buzzing.

No, I have the ground connected to the sleeve and the imput signal connected to the Tip.

I am going to make an extention, I will stick a jack plug in my mp4 separately from my jack - jack cable that I use for connecting the amplifier to the mp4, to the jack-jack cable I will add a jack socket with wires conected, and I will move the wires manually on the jack plug that is inserted in mp4 to observe the behavior, maybe I will figure it out.

 

I am to the limit.

I had inserted the jack plug in the mp4's jack socket and with the free two wires that are going to the input of the amplifier I had tried all the combinations, and nothing else than brrrrrrrr.

I have removed the jack plug and I had simply fitted the wires in the mp4's jack socket, the ground to the sleeve, and the signal to the bottom of the jack socket, and It played.

I becamed angry, I have found an old mini casette, I opened it, and I had connected the input of the amplifier wires directly to the wires that were supplying the mini casette output jack socket. It worked.

After that, I have insereted a non-wired jack plug in the jack socket of the mini casette and when I had connect the amplifier's wires to the supplying jack socket wires, didn't worked any more.
From this I supposed that is something wierd with the jack plugs that I using it.

But I had tested a speaker with one of my jack plugs and it worked. I don't have a clue about what's happening, no explanation, if somebody have a clue, please ligt my brain because I loosing my minds.

I will try tomorrow to find and buy an mono jack plug, maybe it will do the difference.

 

I didn't find a mono jack plug but I have improvized, I had cutted down the top of the stereo jack pkug ( the TIP ):


After that everything worked fine. I think that a mono jack socket would solve the problem.

I still don't know why the stereo jack plug didn't worked. Anyway it was making trouble, but I don't know why?

Another problem I think, is that my integrated circuit is heating verry much, I don't know what to say about the radiator? iti is to small?



Now, I intend to go ahead with the PCB, because my little experiment is made on a test board:


And I will test what I made by now to find as many as possyble tehnical data about amplifiers.

 

You cut the TIP from the plug so I guess you connected the hot wire to the RING instead of to the TIP of the jack.

 

of course , and it's working now, but I don't know why with the stereo jack plug didn't work, for me is a mistery and I can't explain that to me.

 

I have transfered the components from the test board to the printed circuit board and the signal it's not amplified. Please tell me where to look after problem?

 

I have misplaced the R5 - the feedback resistor to grownd, at 100K, but the right value was, 4.7K. problem solved.

 

The result of my work:




And now the jack plug and jack socket are working as it have to work, I am not anymore forced to cut the head of the jack plug.