DCB1 questions,

[gbullimore]

I have already had a search and not found an answer to these.
if someone could help to answer i would be very grateful.

input resistor,
my stepped attenuator has a log curve and a constant ~9k output impedance,
i assume changing the input resistor (to ground) to 1M will be the correct thing to do?

The input resistance of the attenuator circuit depends upon the
relay setting (the volume), but will always be above 22Kohm. The attenuator output impedance is a constant 8.9 Kohms

 

[william2001]

I think the general rule of thumb is 10 times higher, so if the buffer "sees" 9k then I would put in a 100k resistor to ground.

 

[gbullimore]

I thought the 10x was when using Lin pots?
With a log pot I figured I only needed a pull down resistor in case of intermittent input connection.