question about supply for 9v mixer

Hi I have build this small mixer. http://space.tin.it/scienza/fladelle/Page53.htm
now i have build op only one chanel. And I am wondering if the
supply can be made in a smarter way .
because all these caps and 22k resistors are maybe double work??

What I was thinking is if the circuit can be made with a supply like this
http://sound.westhost.com/project43.htm

So that it still run on one single 9v battery but All the pin 3 at the single op amp are running from Gnd and the dc blocking cap are used it the input circuit and the after the out put op amp.

IS it posible to do like that ? are the 100 k and the 560R still needet?

Im making balanced output, only mono so im feeding the sec output op amp from 1 to 6 with 150 k and also change R 7 and 8 to 150K. because I have cancel the balance control .

It work just find.

I want to intruduce a phase shift sw after the input module,
can i change the op amp to a dual and run it like when i make balanced output ?
Then make a sw between the inverdet ond non inverted output,
im not sure how to do it because it has variable gain (R9 )

Any help is very wellcome jc DK.
 
Yes, you can do that ! But you'll still need the polarizing resistor on non-inverting inputs (R3 in the input module) and a few capacitors to your new ground. The 560 ohms resistors in series with the outputs are here to limit output current and set an output impedance and can be reduced, if the op-amps used are short-circuit protected. The 100k at the output provide a discharge path to the output capacitors and should be left if you keep the capacitive coupling.
To create a mid-point, an interesting component is TLE2426 from Texas Instruments, the same function as project43 but in a single TO92 package ...
The phase inversion can be made with an gain of 1 inverting amp following the input op-amp, as you intend, the variable gain being on the first stage only will set gain for both in-phase and antiphase outputs.:)