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

Showing 4 responses by podeschi

And the stock tweeter jumpers are lousy. I replaced my jumpers with the Duelund Cast .6 resistor on the tweeter and an Empirical Designs custom jumper for the midrange.
I tried the Cardas jumpers (have a new set if anyone wants to buy them). It was like using resistors...Cardas smoothed/dampened the sound out a little too much for my likes. The Empirical Designs are the bomb.
Pass Amps are great and I've heard that the xa100.5s will drive the Maggies no problem so the 250.5s shouldn't break a sweat. I use a VAC 150 wpc tube amp and they play loud without breaking down on the 3.7s.
I am very adverse to silver in your face etchy sound. The Emp Designs are transparent and fast but not forward.