can you learn me some electronics?

[tINY]

Originally Posted by doulos30

My question

is there a benefit of using a high grade opamp for this task like a burr brown vs say a 741 since it’s not a part of the audio path will it make a audiable difference why or why not?

Not quite sure where you are talking about adding this circuit...

If it's a servo on the front end (or just a DC reference), then a slow op amp is fine (too fast can have issues...).

If you are generating the "-" for the headphones, then it is actually in the signal path and you need an amp equal to the L and R amps.



-tINY

[doulos30]

it is to take a single rail supply like a 9 volt and turn it into a dual rail + - 4.5volt supply I was told an opamp voltage splitter was more stable then a simple resistor divider to make the virtual ground reference.



is there a benifit from using say a unity gain burr brown like a opa 137a vs the 741 will it make a audible difference in this setup why or why not?

the max chip is a charge pump that allows you to take a 9 volt and generate a + - 9volt supply from 1 battery it obviously has oscillations, but they are suppose to be outside the audio bandwidth like 50 to 60 khz

[tINY]

That will work if you add some caps gnd to rail.

Better yet, you can control the HF response if you use an R and C instead of directly shorting the output to the inverting input. You don't want the op amp to be fast here.

As for the 660-type charge pumps: Add enough capacitace and you should be fine for lower power stuff - mind your currents. I'd shy away from them for a headphone amp. It's really easy to stack two 9v batteries and get +/- and gnd....




-tINY

[danielphantom]

I don't know if you're interested in a little bit more complicated amp, but there is something called an O2 Objective headphone amp, it is mentioned elsewhere in these forums and there is a link to the website of the guy who designed it. I built one and keep it next to my bed to power headphones at the end of the day.

good luck,

Daniel

[doulos30]

I'll get to the 02 proably I"m working on a 12AU7/ IRF510 headphone AMP this weekend after that I got the 12AU7 CMOY then I'll proably do the O2