Headphone Power Buffer

[Einric]

The supply rejection shouldn't be a problem.
I believe the 4556 has a 90db PSRR.
My PSU has a full wave bridge feeding 5600uF--15mH(15Ω)--5600uF, my PSU should be a brick wall to noise.

 

[arnyk]

What about a Buffer IC?
LME49600 by Ti as an example.
driven with a low gain or zero gain opamp or even a jFET.
Still a good "software" learning experience.

There are a number of ICs that seem to be designed for high performance headphone amps and the LME49600 is one of them. Gobs of bandwidth, low distortion, and 250 ma peak current output. It is a mini power amp!

The ADA4898 is another modern goodie, with *only* 150 ma peak output.

The big benefit over paralleled legacy chips is simplicity and surprisingly enough often even better performance into Lo impedance 'phones.

The other advantage or more modern chips is the ability to be really happy with low supply voltages, which is important if you want to go mobile or USB or do battery power for low noise indoors.

 

[Einric]

Ok, so I had a batch of 10 of these PCB's made.
I'm looking to make a Mouser order for the bulk parts to populate these 10 PCB's.
Would anybody be interested in buying a kit from me building it and giving me their honest feedback?
I'll post some pictures later today.

Thanks

 

[Einric]

Board Shots

Here are the boards with 1 populated.
This sounds very neutral except for the times where the bass gets more authority because of the nature of the current buffer.

I'd be looking to put some kits together if anybody is interested.

 

[Pano]

Einric, would you like this thread moved over to the Headphone section? Seems a better place for it, especially now that it's built.

 

[Einric]

Shoot YEAH!
Thanks!

Depending on the amount of interest I will create a group buy if there are heaps of people.

 

[Pano]

Moved to Headphones

 

[Einric]

Thank You