geofex-based relay switched panner

[egasimus]

Hi. This is one of my first forays into circuit modification and development, and I'm afraid I'm going to need some help. Basically, I'm building a device based on R.G. Keen's effect panner ("Panning for fun", pg. 2, the second circuit). It, however has two modes: (1) dry/wet ratio controlled by external volume pedal, and (2) dry/wet ration controlled by internal potentiometer, volume pedal regulates volume at some point in the FX chain. The switching between those two modes is done with three DPDT relays. I have decided to add this circuit (from here) so that the relays don't make a "pop" in the sound. And here's where my problem is.

I use the 4.5V bias voltage for the opamps for both a control voltage ("+on/-off") and a relay switching voltage ("+12V" on the circuit - my relays are actually 5V ones). However, when I connect +4.5V to the point marked "+on/-off", the voltage drops to about 0.6V.

here's a simulation

What do I do in order to keep a steady 4.5V and not have any artifacts in the sound?

[egasimus]

If anyone's wondering, I found the solution. The 47k resistors which give you the bias voltage (VCC/2) for the opamps limit the current, so the relays would always cause a huga voltage drop. The simplest approach is to feed the relay coils from +9V through a separate resistor (39ohm/>0.5w in my case). If you're not using a regulated PSU, however, overvoltage could fry the relays so put in a simple 5V regulator using something like LM317 or 7805, and off you go.