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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
ralvarad
7 posts
 
bought my first system in about 1987.
magneplaner IIc with an onix integrated
amp ( 30 watts per channel). didn't know
any better. but listened to 'thus spake zarathrustra'
many times and never had to ask myself "where's the bass".
never shutdown either.
Ag insider logo xs@2x
podeschi
301 posts
 
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.
hasse
230 posts
 
He had not installed the tweeter jumpers. No wonder the amp shut down.
Ag insider logo xs@2x
podeschi
301 posts
 
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.
hasse
230 posts
 
Yes, I´m using the Cardas tweeter and midrange jumpers on my 3.7´s.
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