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Using Adcom GFA-555s as monoblocks to power magnepan 3.3s in active biamp

Yeah, a long title but it says it all.  Presently I have my rebuilt Magnepan 3.3rs actively biamped through a Marchand active crossover, then using 2 stereo amps to power bass and mid/treble respectively.

I am considering taking two Adcom GFA-555s and bridging them and using one each to power the bass panels of the maggies. 

Since the Magnepans are 4 ohm rated, however it's only the bass panels I'd be powering, what are your thoughts on stability?

Appreciate the help.  Don't need suggestions on "selling all my amps and buying one bigger one" - I have a lot of different amp options but am a tinkerer and want to see if the power of a bridged adcom would be good to control the bass panels. 

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Showing 1 response by musicfan2349

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musicfan2349
204 posts
 

In a somewhat analogous situation, I ran a pair of Hafler DH-220s bridged into a pair of Acoustat 1+1 and RHLabs sub. I thought  it sounded fine until someone smarter than me pointed out that the amps were likely quite unstable in that configuration. So as an experiment, I switched them out of bridged mode and used only one channel of each amp to drive the speakers.

I could not believe my ears at the improvement! Even with "less" power the sound was much better, more cohesive top to the now much better bottom. Others here have explained it better than I could but the bottom line is, I have practical experience to say that bridged is NOT the way to go in a low ohm situation.

Happy Listening!

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