impedance matching options sought

[Eric Weitzman]

I have a 250K stepped attenuator that I wish to use as a passive linestage before an active line-level crossover/equalizer. The input of the xo/eq consists of a 6th order RC LP filter for RFI attenuation on the non-inverting input of an opamp, while the opamp then implements a shelving high-pass filter. The RFI filter has a nominal 10K input impedance.

I can see several options:

(1) recalculate the input circuit values to have an impedance of 100K
(2) add a buffer with 100K input impedance before the input circuit.
(3) transformer coupling

Are there any others?

I'm not interested in transformer coupling, might as well replace the passive with a TVC if I was to go there.

Other than parts count and/or cost, the only tradeoff I can see between (1) and (2) is more resistance/noise in the signal path, vs. an extra opamp. Any others?

- Eric