[timmeke154]

Hi,

I recently bought :

eBay.be: New Headphone Stereo Amplifier Kit DIY OpAmp Cmoy Amp (object 250392957210 eindtijd 19-apr-09 09:51:52 CEST)

one of these...

Soldered it today, and plugged everything in..

Turned it on.. A very unclear sound.. and suddenly it stopped..., but everything did.. Now, i hear very little sound if i put it on the max, and the microchip is HOT

Burned?

Or how?

 

[v3nom]

If there is heat you may have a short somewhere. Check all your solders very carefully.

 

[ph33lix]

Take plenty of good and clear pictures.
Keep a multimeter handy in case someone asks you to take some measurements.

Have a second dual opamp on standby in case a short killed the one that came with the kit.

 

[chews89]

The same thing happened to me and it turned out I had a solder bridge. Check your board and clean up any obvious mess. If it still doesn't work, take pictures and the folks here will try and help you out.

 

[timmeke154]

Ok thank you

I'm now soldering a connection that is on the electric scheme, bot not on the picture

Will try that.. no unclean connections as far i can see

 

[timmeke154]

The scheme isnt quite right if you look at the pictures :s You cant see anything on the scheme about the 3rd jumper on top of the picture.. Will try to add this one

 

[NelsonVandal]

There's no caps at all in this amp!?

 

[ph33lix]

Quote:

Originally Posted by NelsonVandal /img/forum/go_quote.gif There's no caps at all in this amp!?

Say... I just noticed this too. I know caps are quite hated by some "extremists" but this is just... wow.

timekke>> You might want to doublecheck your wirings especially to the batteries.

Also in this setup, make sure BOTH your batteries are brand new. Slight differences in voltages mean a certain amount of DC offset and headphones don't like DC offsets in the long run.

Start taking pics now if you still have problems.

 

[timmeke154]

Few pics:

http://img102.imageshack.us/img102/1720/dscf0071.jpg
http://img5.imageshack.us/img5/8099/dscf0072s.jpg

Thanks!

 

[ph33lix]

Ok, now you need a multimeter set to DC volt reading setting.
Have the opamp socket's notch oriented to your left (pinout represented by the lame diagram I made below).

_________
| 8 7 6 5 |
) opa skt |
|.1 2 3 4 |
------------

WITH THE OPAMP REMOVED and batteries plugged in, please provide readings of having the black probe at Pin 4 and the red probe at Pin 8. You technically read 18V give or take a volt or two.

Then have multimeter's black probe changed to an aligator clip (if you have one) and clip it onto the headphone jack's outter rim.
With your red probe, take readings readings from pin 4 (you should get about -9V) and then from pin 8 (you should get about +9v).

If your values don't match these values I've put up, you may have a problem with the soldering somewhere and won't hurt to just reheat each joint and add just a touch more solder from the look of your pics.

Good luck.

 

[Juaquin]

Your opamp is most likely fried, meaning you probably have a short somewhere in the power supply portion of the amp. Track down that problem, then replace the opamp. Post pictures of the connections if you can't find where it's (most likely) shorted.

 

[B00MERS00NER]

If you don't my chiming in here...

When you reflow those joints, use plenty of flux - it will help the solder flow and get better coverage. Also you will want to be careful when you solder around those SS components, too much heat can kill them.

You also may want to take a look at those wires, do they have broken strands on them?

You are getting some good advice from everyone and sounds like you are in good hands with them.