Which pwr. amp for Kappa8 speakers?

jeanmarie

AK Subscriber
Subscriber
I inherited a pair of infinity Kappa 8 speakers and I want to pair them with a Mcintosh amp. I do own a pair of restored MC-75 mono blocks but I am afraid they wont do the job. What amp would you all suggest to power these power hungry speakers?
 
Well, I'd be connecting those speakers to the MC75s first for a quick listen. Sure, they've got a rep for being difficult loads, but MI75s (industrial version) were used for all kinds of difficult loads in industry, etc.

Don't be afraid to play with the connectivity of the speakers to the amplifier speaker taps in an effort to get good sound. Once you've determined which taps drive the speakers best, you may find that you're all set. On the other hand, if you can't get the Kappas loud enough, you may elect to move up in power.

I'm the wrong guy to ask "how big of an amp do I need?" . . .
 
I understand, I have hooked them to the 75's but I have heard to many horror stories of them burning up amps and these 75's are my babies. They do sound great with them. Is there any possibility that they will damage them at higher listening levels?
 
Well, we're talking about McIntosh amplifiers here. Me, personally . . . I wouldn't be scared one bit. I can understand your reservations though as the Kappa 8s certainly do have a reputation for being a difficult load at certain frequencies - some report dipping as low as 2 Ohms at certain frequencies.

I'd use the 4 Ohm taps, which you likely are. Maybe c_dk, ron-c, or twiiii can comment on how the MC75 will behave when driving a load that dips to 50% of the tap impedance . . . I'd love to know as well.
 
Oh, and to answer your original question, any SS McIntosh amplifier with 2 Ohm taps would be a good choice. You may not even need the 2 Ohm taps, but it would be nice to have them to experiment with. The MC7200 would also be a good choice as it is direct coupled and was designed to make big power with speakers that have a difficult impedance curve.
 
I have owned Kappa 8's for over a decade and have had them hooked up to many SS amps and a few valve amps as well. They ARE difficult loads and have couple sub 2 ohm impedance dips that create grief for most amps. That said they are the most musical speakers that I've ever owned and I don't think I'll ever give them up!

I had heard about the McIntosh reputation for years and decided that it was time for a taste. After a lot of research (and help from fellow AKers) I decided to go with an amp that had autoformers to address the Kappa's impedance issues. Based on my previous amps I knew that I needed something with a minimum of 200 WPC to generate the SPLs that I enjoy with rock music. I wound up finding a really nice MC-7300 that appeared to fit the bill. Deciding to go McIntosh all the way I also picked up a C37 preamp (wonderful pre and can't live without the remote).

After some experimentation I ended up using the 4 ohm tap because it was the best compromise between gain versus heat generation & turning on the Power Guard lamps too frequently. My critical listening impression was that the low-mids & up were just amazing...liquid and lush, along with beautiful definition and a big 3D soundstage! But to be honest the lows were a little rounder than I liked and not as punchy as I had envisioned. I was also not getting the decibels that I had hoped for.

Time to bi-amp...
I knew that the 7300 would work well with the mids & highs. After some amp cycling on the bottoms (McIntosh MC2200, Sansui B2101 & B2102, Crown SA2, Philips AH578) I settled on using a Rotel 1090 on the woofers. The 1090 is direct coupled, puts out 700 WPC at 4 ohms with a damping factor of 1000 and controls the woofers nicely. I got a few more DBs out of the system before the Power Guards lamps lit up (though still on 10-20% of the time when cranking) and both amps ran cooler.

I now have system that is like a velvet glove with brass knuckles underneath...smooth & warm yet packs a nice punch when needed! I have become a devote McFollower and absolutely love what comes out of my Kappas..."tube-like" (overused I know but it's true!), non-fatiguing and just plain delicious ear candy! I have been in the pursuit of "the system" for decades. Don't know if the hunt is over but I do know that it's time to sit back enjoy this one for a while!

Good luck with the Kappa's, they are wonderful speakers!
 
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Now that's the info I am looking for. I really appreciate it I knew I could count on you folks here at AK to point me in the right direction! Thank you so much!!!!!!!!!!!!
 
It is very much appreciated dmacman this is some excellent info. I am currently eyeing a mc 7200 on the bay I just hope it don't go sky high on me.
 
WOW! That's incredible that you have a pair of Kappa 8's and MC-275's. I have Kappa 8's and MC-250's which are comparable to the MC-275. I put the 250's (4 ohm tap) on the upper and a single MC-2100 on the lowers and that combination was spectacular. I have been messing around with different speakers a lot but I am going back to that combination whether my wife likes it or not. The speakers are a bit intimidating but man, WOW! Have fun! Oh, you will:) BTW all three amps handled the kappas with ease and hardly got warm.
 
Bi-amp them...
The direct coupled, higher damping and no autoformers 7200 should give you tight punchy bottoms that will complement your MC-75 tubes on the tops.
 
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