New to Preamp - Preamp suggestion around 10k

@op - it always helps to provide as much information as possible.

Which Stax Earspeakers and which energiser are you currently using?

@cming0038. Thanks for clarifying that you have top of the range Stax equipment.

To be frank, I don't think what you are trying to do makes sense. The only thing the bypass function on the 8000 does is to remove the volume control from the circuit. So your signal will still be going through all of the 8000s amplification circuitry and all you will be doing is to precondition the signal by putting it through a preamp before you input it to the 8000.

I don't think that will radically alter the sonic character of the 8000 though that can only be known by trying it, I suppose.

Though I rarely recommend buying two of anything, you might be better investing in an alternative setup with a top quality pair of dynamic headphones. You may have done that already, but you'd description of what you want to change in the Stax's is, to me, fairly reflective of the basic differences in character between electrostatic and dynamic designs.