A balanced (differential) Bottlehead Seduction phono preamp?

[Mikey]

Now run the numbers again with a smaller load resistor, and see how that reduces dependence on the source resistance.

OK...here are the results, varying only Rload (maintaining a 24K source impedance):

RL = 10M, R1 = 42.7K
RL = 1M, R1 = 47.0K
RL = 500K, R1 = 52.4K

It seems that as the load impedance(RL) decreases, the larger R1 becomes.
The larger R1 gets, the less effect a variable source impedance (RS) will have
upon the 'total' source impedance seen by the network, correct?

Is there a practical limit to how small the grid resistor of the next stage can be?

Mike

[Paul Joppa]

...Is there a practical limit to how small the grid resistor of the next stage can be?

It reduces gain by RL/(RL+RS+R1) - it's a potentiometer or voltage divider.