Mc 240 vs. Prima Luna

Here is something I would try if I used horns, I don’t. Not because I don’t like them. I just had to make a choice on what I was going to use. I went with domes 50 years ago and small planars/ribbons 30+ years ago. I haven’t tried a bridged Mac on your speakers. For all I know it might sound great..

8-84" of push pull ribbons drivers don’t sound so good though. I might have spoken out of place.. Do a listen on a single speaker bridged at 80 vs a mono or stereo at 40 watt, they sound different (stereo vs dual mono vs bridged). I’d try it series and paralleled but stick to one speaker.  I’ve done it both ways with a 275 it does make a difference for high frequency ser vs par and clarity with spl..

A MC275 with a healthy PS will push a 1 or 2 ohm load. You can fry eggs on them too. BUT they keep on running as long as you keep a fan on them. I’ve seen Macs keep on driving Infinity 9.0 Kappa and only get hot, when other amps were dropping dead like flys with that speaker. Krells, Mac SS MB, Mac MC23 or 2500 Threshold, Pass, Modded Son of Ampzilla and a Mac MC275 no problem.

Regards

@oldhvymec makes some really good points.  The MAC tube amps bridged to mono never sound as good as they do in stereo. Have tried it myself several times with a 240, 225 and 275. The Klipsch are pretty easy to drive. As far as the PL amps go, would also agree with the other posters, not was warm sounding as the MACS. 

What the original poster may want to consider to spending the sum on powered subs, and let the MC240 handle the midrange up. 

@oldhvymec 

I am now curious what my system would sound like if I used my one of my MC275 amps to power the lowers on my speakers and one MC275 to power the mids-highs in my speakers. It might be worth trying this setup to run the MC275s in stereo instead of mono since my horn speakers can be bi-amped. I can’t try it for two weeks though. 

I would sure give it a try femoore12. Just so everyone knows, I do NOT use valves to run bass. 300hz and down is SS.

80hz and below is normally GR OB servo subs

100-300hz is direct coupled to 12k class Ds and 6, 8" mid bass drivers per column and I use a 2496 active XO.

300hz up is all valves and I use a hybrid line source of 8" Monsoon planars and normally a single Aurum Cantus ribbon tweeter. I use a lot of their drivers. They have a great AMT too.

I do have one system I listen to when I’m in my work room. MC225, MX110z, Sony ES777, Thoren 124 and a pair of tricked out Infinity RS4bs. That system is old as dirt, but the system I listen to most of the time.. The only place I use tubes for bass and it is the smallest Mac (25 wpc) I own. it’s funny. Sure sounds good.. It’s actually my favorite for itty bitty, Just don’t tell anyone.. LOL

Regards

As a McIntosh and PrimaLuna owner, there could be pros and cons to either depending on what you value as an owner.

MC240:
You know you like the sound paired with your Heresy's. Another 240 may (or may not..because mono) be more of a good thing.
McIntosh gear has a reliable support network, long term reliability, and holds its value. Also made in the USA, so yay!

PrimaLuna:
I own an Evo 300 Power amp and is about as maintenance free as you get in tube amplification.

Tube variety...you may get the warmth you seek with a new issue TungSol 7581a tube set, but overall, the new PL gear is pretty neutral compared with tube amps from the 60's. KT88s and KT150s sound fairly punchy and quick, and while the KT150s will net you a few bonus watts, it seems every other tube coming off the line is faulty in some way. Teething issues? Perhaps. Sh!t luck on my part? Probably.

Warranty: 3-year warranty if you register it. Also...made in China for what it's worth.

Out of curiosity, any reason the AudioClassics 9B isn't in the running at this price point? It's a VAC amp in a vintage Marantz suit.