Vandersteen 5A HighPass M5 Crossover

I think you will need one custom made. The stock unit only goes up to 400K.

Mehdi, which SS amp has an input impedance of 1M Ohms?

I'm with 4yanx on this one -- I have never heard of a SS power amp with an impedance higher than about 100k ohms. Tube amps often have input impedances in the 100k ohm or higher category.

Oh, I'm not saying there ISN'T one, just wondering which one it is. My McCormack was 100K Ohm before I had it modded (now 10KOhm), and I thought that was high! I have thought about perhaps having a dedicated filter made for this amp to avoid the dip-switch circuity. Wondering if it would be worth the efoort.

If it is truely 1m ohms(which I have never heard of in a SS amp), a custom filter would be required. What model and brand amp is this?
You can always call the man himself.