Why is the potentiometer 100k? Let's say I wanted to use the Sweetest Whispers stepped attenuator kit from Bottlehead; it's rated at 15k. What issues would I run into trying to use this in our preamp? Can the Sweet Whispers or the preamp's circuit be modified to make this work properly?

In reality I'll more than likely go with Alps Blue Velvet. Is this a good choice?

.....Colin