Grid current bias

On the Tube Circuits for Audio Amplifiers - Mullard book, this term is used on the 4 channel mixer (adder) circuit diagram.


The EF86 has a 10MΩ resistor from grid to cathode. Cathode is connected to ground.


Why does grid current flow? This should be current in the opposite direction. When cathode emits electrons it becomes positive (by lack of electrons or surplus of protons). Grid becomes negative. So when they are joined by a 10MΩ resistor current flows.


The negative grid (by electron emmision from cathode) is pulled a bit up in potential by the higher potential cathode.


It is interesting that in the case of a low Z mic, the Mullard book specifies the use of a step up transformer. One lead of the secondary is connected to ground. The other lead is connected to a 10MΩ resitor shunt by a 5nF capacitor. Their other side is connected to grid. In this way the grid current passes through the secondary of the transformer, possibly magnetising it. Is this a way to operate an input transformer in class A (electrons flowing all the time?).


This has not yet been tried on a Pleiades V6 electron tube mic booster amp. Normally the grid resitor is connected to anode for further pull up bias so that operation can be with a very small anode potential. But the grid current is not let to pass through the input transformer.


How would the Pleiades V6 sound if the secondary is connected to say 10MΩ resitor shunt with a capacitor and their other side connected either to anode? Or Vb? The other lead of the secondary connected to grid.