I have been reading R.G's excellent article on Geofex called "Designing Bias Supply (Vbias or Vb) Networks for Effects", found here

http://www.geofex.com/circuits/Biasnet.htmAnother article I have read about this topic is Tangensofts "Virtual Ground Circuits", found here

http://tangentsoft.net/elec/vgrounds.htmlI thought I understood what the current draw on the biasing network was ( while biasing an opamp) after reading R.G's article: the input bias current spec found in the opamps datasheet.

But then I went to the Tangensoft article, and it has a diagram and text that explains that the load also draws current from the voltage divider, using this diagram and text:

"The 1 mV battery (Vos) simulates the op-amp’s input offset voltage. This is a reasonable value for an OPA132, though it does vary between chips in practice.

This offset forces 1 mV across R3. Because op-amps always force their input voltages to be equal, this in turn forces 10 mV across R4. As you can see, this puts 11 mV of DC across the load. If the load is 32 Ω at DC (such as a pair of Grado SR-60s), 0.34 mA is forced through the load. This current can only come from the rail splitter, which looks like two parallel resistors to the load. Ohm’s law tells us that since the current is 0.34 mA and the resistance is 2.35 kΩ (two 4.7 kΩ resistors in parallel), the voltage at the midpoint of the divider is forced ~0.8 V away from the ideal midpoint."

But we in the stompbox world use a capacitor before the load, and we don't reference the load to the virtual ground but to the "real" ground.

I wish I knew more about physics, but this means that the Tangensoft problem is not in effect while using our topology right?

Did I understood well that R.G. explains in his article that the only current draw on the bias network is the input bias current?