Virtual ground / Rail Splitter using only LM317

[JediRemi]

Hey guys,

sorry for this probably very basic question, but with the mess that the "search" function is returning I could not easily find my answer.

I wated to build a rail splitter for a headphones amp out of what I had in stock.
And I have Lm317 and only that.

So I've designed a circuit that works when simulating it.
I wanted your opinion.
Would that work ?

(the strange resistors values comes from what I have in stock too).

An externally hosted image should be here but it was not working when we last tested it.

 

[geraldfryjr]

A cheaper method would be to use two resistors of equal value as described here

http://www.diyaudio.com/forums/software-tools/185906-op-amp-virtual-ground-spice.html#post2519453

If a lower impedence is required than what the resistor divider provides then it can be followed by a unity gain opamp and the output of the opamp becomes the virtual ground. jer

 

[geraldfryjr]

Using lower values of resistor lowers this impedence but it also increases the current draw on the power supply.
The opamp buffer allows a lower impedence for the virtual ground.
This works of course depending on your application and current levels required returning to the virtual ground. jer

 

[mchambin]

The posted schematic cannot work.
Because current from U2 is one way only.

 

[digits]

It just does not strike me as efficient enough for a portable application like a headphone amp on a battery.