*Project* - CMOY Headphone amp

[p4radox]

You check if it's a capacitor problem, just short out the input coupling capacitor.

But definitely give an output resistor a shot. It made the biggest difference to the hiss for me. Maybe try the star grounding system that was discussed on page 1.

 

[p4radox]

I agree with the question mark over R3. It was the first thing I went for when trying to eliminate the clipping effects I was experiencing, even after switching to the 741 circuit, and after removing it I don't hear any clipping anymore.

 

[p4radox]

I'm pretty sure this is the exact design I went with in the end:

The 0.47uF caps were physically too big, so I stuck with the 0.1uF ones.

The key features that solved my problems were getting rid of the feedback resistor in the power supply's op amp circuit (see above: the 741's output feeds directly into the inverting input), and the use of an output resistor just before the stereo jack output (150ohm above).

 

[p4radox]

OK - a wee bit of topic here P4radox but i clicked your link from the Leeds/Wembley thread.

Simply to say, as a Leeds Lad, do you remember M&B Radio by the Dark Arches, shut down now unfortunately - I used to love going in there (late 80's) for component parts and looking at all the old retro gear (that will be worth a bomb now)

Given the chance (nowadays) I am still a pretty dab hand with a soldering iron.

Good memories, cheers

Can't say I've heard of it unfortunately. How long has it been shut? I'm probably far too young to remember.

 

[p4radox]

You obviously need to build one with multiple inputs then.

 

[p4radox]

Farnell and Rapid. I'm pretty sure they're okay to link to as they're always mentioned in the DIY audio thread.