Shure A15AS XLR attenuators.. anyone tried them?

I'm currently using Rothwell 10db XLR attenuators but need more attenuation before my amplifier. Has anyone tried the Shure A15AS XLR attenuators?
No, but I'm pretty certain they would not work properly for you. They have an input impedance of only 1000 ohms, and are intended for use with low impedance microphones. That would be too severe a load for most audio components.

-- Al
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EVS's web site describes their attenuators as follows:

"The low impedance version works best with solid state amps and can be used for tube amps as well. It has a 1K input impedance at low volumes and has a somewhat higher input impedance at higher volume settings. The output impedance is always below 1K and usually in the 100 ohm range in normal use."

The impedance specs on the Shure are the same. I should add that I have pro audio gear in my chain and directly before my amp, a PS Audio HCA-2 which has 100K input impedance.
I just bought an NHT PVC Pro passive volume control (at a great close-out price). It sounds fine to me. Attenuator problem solved. Thanks, Bob R.
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Anyone has compared the passive NHT PVC Pro to the active SPL Volume 2? Both are XLR devices and operate symmetrical but not fully balanced.