Pass 250.5 shuts down driving Magnepan 3.7


This is my first post so please bear with me.

My Pass labs 250.5 protection circuit shuts the amp down when I drive my new Magnepan 3.7s at high volume. I'm talking about a volme higher than I might consistently listen, but not an unbearable level.

I'm using a Cary Slp 05 preamp with long balanced ICs (25 ft,) The amp is close to the speakers with less than 6 feet of speaker wire. The system works fine at normal volumes. I've tried the same thing with a pair of Cary MB500 (750 W @ 4 ohm) and they too shut down at high volume.

I believe the maggies drop below 4 ohms and I wonder if either amp can handle the impedance drop below 4 ohms.

Has anyone experienced this issue ?

Any suggestions ?
gcoxsom
"Cardas smoothed/dampened the sound out a little too much for my likes. The Empirical Designs are the bomb."
I think I read somewhere that the Empirical Design jumpers are made of silver plated copper? All silver plated cables I´ve been trying have had a "tweeter-in-your-face-sound", is this true for the ED jumpers?
I am very adverse to silver in your face etchy sound. The Emp Designs are transparent and fast but not forward.