Suitable PSU for OPA627+BUF

[ShieldJaguar]

Hi ppl,
Built this circuit as a headphone amp, currently running it using 4x9v batteries and would like to convert it to AC power. Also should i have input caps?
My source is a iPod and cans are HD600s.

[peranders]

The need for input caps has nothing to do with batteries or AC power supply. It's your signal source and I'll guess it's still iPod?

[tlmadsen]

Use a "in-wall" transformer, a brigde, a copule of E-lyt (2200-4700uF) and a set of LM317/Lm337 regulators and you are of.

Thomas

[richie00boy]

You can't use a bridge with a normal/common AC wall-wart to get split rails of any real capacity. You must use a half-wave voltage doubler. See ESP project P05 for exactly what you need.

[brianuk]

I agree with the Maplin line Rich

Oh yes and on topic! the P05, I use one and it'll do exactly what you need Shield. Funny though all the parts I got came from maplin, even some 47 Ohm resistors instead of 47K that I wanted

[jackinnj]

Originally posted by richie00boy
You can't use a bridge with a normal/common AC wall-wart to get split rails of any real capacity. You must use a half-wave voltage doubler. See ESP project P05 for exactly what you need.

You can use a DC Wall Wart and split the rails -- one of the ways is to use a power opamp to create an artificial ground, I can't find the schematic I posted about a year ago, but here is something similar from ESP:

[richie00boy]

I knew somebody would post something like that It's more complicated though and still has a limited load that the artificial ground can cope with, but it should work OK for headphones.

[jackinnj]

Originally posted by richie00boy
I knew somebody would post something like that It's more complicated though and still has a limited load that the artificial ground can cope with, but it should work OK for headphones.

you can always use a Burr-Brown opamp on steroids.

[Pan]

I used a BUF634 as ground driver with two 9V batteries and it was very good. I used it in class A mode to make sure it worked as a shunt regulator for all dynamic situations.

/Peter