[Monkeypaw57]

Can the Fosi zv3 drive Maggie .7 and how does it sound

[FullRangeMan]

Can the Fosi zv3 drive Maggie .7 and how does it sound

To drive a low efficiency speaker as this 86dB and 4Ω (3Ω most of the range) you will need a powerful amp with a muscular power supply, minimum 200W or more.

[HAL]

Are you talking about the FOSI ZA3 stereo amp?

If so, upgraded mine with LME49720 opamps and it sounds very good.  Others are using the Sparkos SS3602 discrete opamps as upgrades. 

The original NE5532 opamps are a very old design from the beginning of the CD days.  Most modern audio opamps outperform them in audio equipment.

I have used the ZA3 to power 12in open baffle subs with great results.  It is 180wrms into 4 Ohm loads.

Will be getting a used pair of Magnepan LRS+ speakers soon, if they are in good shape, to test with the ZA3.

[I.Greyhound Fan]

Certainly, get the 48v power supply.  The question is, do the 0.7's drop down to 2 ohms?  I doubt the fosi can handle that for very long but that is a question for fosi.  If you go to the ASR website, distortion increases in the high frequencies as power goes up reaching about 10 percent at 140 wpc at I believe 4 ohms.

https://www.audiosciencereview.com/forum/index.php?threads/fosi-audio-za3-amplifier-review.52139/

Offloading the bass like you are doing should help. 

Also, Maggies like high current and high capacitance besides high power to sound their best at louder volumes.  I doubt that the fosi has high current and capacitance.  But I suspect that you will be fine at moderate volumes.

[garyalex]

I used a pair of Fosi ZA3 amps with the 48v power supplies in monobloc mode to drive a pair of Magnepan LRS+.  The amps had no problems with the Magnepans. The sound was excellent.   

[rotarius]

My ZA3 was just ok with a Meanwell 48v, 350w switcher.  Anemic bass compared to every class AB amp I own, modern and vintage. 

[ArthurDent]

Greetings & Welcome to AC