Best Amplifier for LS3/5a

Hi Peter,

I have set up, must be over ten LS3 5A systems. I worked in a high end store when the Rogers was released back in the late 70s. 

The LS3 5A is VERY inefficient, like 83 dB/watt @ 1meter. If you are not using subwoofers I would recommend a 200 watt/ch SS class A amp. HOWEVER the only way to use LS3 5As is with stereo subwoofers and a two way crossover, preferably digital. You want to cross at 100 Hz. Taking that bass away from the LS3 5As lowers distortion DRAMATICALLY and increases headroom also dramatically. You can also get away with a smaller amp, a 100 watt class A amp, tube or SS will do fine. I would use a Pass XA100.8. Another great amp would be the Parasound JC 1+ 

@mspot is correct about 24/7 powered up.

@mijostyn gives accurate information about the LS 3/5A characteristics.  I just do not know how crazy loud or how much bass you will demand for a bedroom system from an understandably small monitor meant for near field moderate levels.

Thanks All.  I agree that a Class A amplifier left on 24/7 under my bed is a bad idea!  The bedroom is small, and mostly I'm trying to TAME bass nodes.  That's a benefit of the Weiss 501 - I am able to use the built in DSP for that purpose.  With my current Raidho XT-1's, I also tune the bass by adding a small KEF subwoofer. 

I would like to also be able to use my LS 3/5A's in the bedroom system. I think they sound very good with the AGD Audion (that's why I kept them), but I am dealing with a little bit of sibilance.  So the question is: is the sibilance a characteristic of the Falcon Gold Badges or is there something about the amp/speaker combo that can be improved (no sibilance with the AGD's driving my Raidhos).  I was thinking that maybe it is the impedance matching, or maybe the LS 3/5A's were designed for an amp with less high frequency extension.

@celtic66 - you nailed it.  Small bedroom, lots of bass reinforcement... don't need much output.  Perhaps that changes the amp matching discussion just a bit...

@mijostyn if I ever use these speakers in a "normal" sized room, your approach sounds good.  Right now my room is 8x12 - pretty small.

But the theme here is very consistent - lots of current needed! 

Check out the Quad 306 (not balanced) listed here on A'Gon.

DeKay

@peter_s 

Then you use small subwoofers. You are doing this as much to lower distortion as to add bass. The LS3 5A was envisioned as a monitor for remote set ups. Imagine a couple of guys in a van like the Rolling Stone Mobile Studio.