[Zentry]

Hello everyone,
Since I'm new to electronics in general I've been having problems with my first CMoy amp. I added the panel components (they are dangling right now) and plugged my MD player into it (source) and then listened using a variety of headphones. Consistently the left channel is audible but just barely, while the right channel produces amplified sound (it seems a little distorted but the source is MD-compression from MP3 audio). I'm using a Burr-Brown OPA2132PA. power supply hookups go into prongs(?) 4(-) and 8(+). Is this correct? Everything else seems to be where it ought to be.

What may be the problem? I'd appreciate any help.

Important

This project is part of my science project. The other to portions are to find the most commonly used crossover circuit (admittedly I haven't used the forum search engine for this yet). The other part is to evaluate the effectiveness of forums like this one. You help there simply by responding. If you would like to be left out of my evaluation please state so somewhere in your post. Thanks for your time.

 

[Budgie]

Have you double and triple checked all connections. It is easy to miss a connection or to make an incorrect one. Try comparing to the schematic, component by component, to make sure each end is connected to the right place.

 

[Zentry]

I checked the connections... I found that the wires that connect the power to the op-amp weren't coming from where they were supposed to. ( they were in the same socket as the LED) so I rewired them so that they went through the capacitor first. but it only lowered the distortion... the left channel is still signifigantly softer than the right. I think that I may possibly have damaged the op-amp during soldering (read: overheated) ... Could this have caused my problems? thanks again for your input.

The panel components I've hooked up are the stereo input and output and the LED... I decided to save the volume control for later...

Joe you mention the battery as a possible culprit... how would that cause my problems(just curious) and what do I have to check for (the 9volt is new btw).

 

[CaptBubba]

Check your resistors, you may just have the gain too low on one channel. I find that opamps are much tougher than I normally guess they are.

I would think that if you overheated the opamp, you would be getting seriously messed up sound, not just a reduced volume.

 

[Zentry]

turns out that the left channel capacitor and resistor led into the wrong op-amp pin. Thats fixed the problem and now I'm enjoying the sound of my first headphone amp!

yay!

I didn't pick up on it before because the previous connection made the amp symmetrical and so the problem wasn't as obvious...


I'm going to go check out the search engine now to find the most used crossover circuit

and continue my sci fair proj... Thanks for your help guys!