[Durendall]

Hey all, I just finished assembling my first ever cmoy amp. I must say I'm not impressed. I'm guessing because I screwed up somewhere. Basically what my problem is, is that I hear no amplification, or even further powering to my headphones (ath-a700, and another cheap pair.) All sound come out properly and my pot does it's job as a volume knob, and the signal flows through the op-amp chip, just doesn't seem to amplify..... I've tested it with an 11 gain and now it's at (roughly) 3 gain (10k/4.75k) I am using my laptop as a source, also tested it with a friends ipod and my zune. Anyone know what might be the problem? Or is it just not having any effect on my headphones because they don't need amplification?

Thanks for your help all

 

[sugrhigh]

Well amplification is amplification so "needing" or not isn't important, it should be louder regardless. But if the volume pot works correctly what's the problem exactly? Is it adding/removing volume but not amping beyond the sound level of the source?

The fact that audio is getting through the circuit means you've got a good signal.....
Do you happen to have an oscilloscope?

 

[Durendall]

I wish I had an ocilloscope, so in a clearer format, no I'm afraid I do not have an ocilloscope or access to one. With the pot cranked the volume level is almost Identical to the source.

 

[sugrhigh]

Hm, then it seems that everything is wired correctly (especially the opamp) but I'm wondering if maybe the gain resistor is wrong. I know you said you tried changing it and such but try comparing the value to the actual band code on the resistor.

The only other thing I can think of is that your headphones have a very high impedance that cuts the signal which is highly, and i mean HIGHLY unlikely