amp for infiinity kappa 9

I looking for advice on which amp or amps to use. I'm in a transition from mid-FI to HI-FI. I want to build a system around the Infinity kappa 9s I just bought on e-bay for 800 dollars. I tried to drive the speakers on a yamaha m2 amp. No dice. It shuts down at moderate volume. Step 2 I tried an Adcom gfa 555. Cooked the amp in short time. I have heard that a tube pre amp is recommended because of the emit tweeters. I currently Use a Mcintosh MC2100. It will drive the speakers to its full power but falls short of what the speakers are capable of. Would another MC2100 work if i used the 2 for mono blocks 1 to each speaker or will I still come up short on power? The system I want to build will be very Basic. I have a Yamaha C2 pre-amp, dyno fm-3 tube tuner, Technics SM1200 tuntable, Nakamichi Dragon cassette deck, Akai GX 747 open reel tape deck,DBX 4bx dynamic range expander, and a Denon DCD 1500 cd player. I also have an ADC SS315 equalizer. Now I am aware that these are not the best componets to use but they are all that I have for now. Any and all advice on what to keep and what should go would be welcome. I listen to Blues and classic rock most of the time but sometimes classical and big band is a nice change. I dont even know how much I want to spend. I will just build the system slowly piece by piece and use some of what I have now. Most of this stuff was bought 20 years ago when I was in the service. Can anyone help this newbie out on my quest for HI-FI?
As I recall these speakers have a substantial dip into low impedences and are fairly inefficient. A friend of mine used to sell them and they really need a very powerful high current SS amp, although you might try a very high powered tube amp (read expensive). I would think a minimum would be an amp that puts out 200w into 8ohms - 400w into 4ohms and it would be a godsend if it put out 800w into 2ohms. Of older amps which you might score that could drive these I think of the Threshold S500's which you usually see selling used for about $1500 or less. They are of about the same vintage as your speakers. Good luck, you picked a tough speaker.
I owned the Kappa 8 years ago. The eMit tweeter is ruthless, and the Threshold was a good recommendation. You need gobs of quality power and current.
I had the Kappa 8's & drove them with the Adcom 565 mono blocks and only blew one or two mid range drivers over an 8 year period.

I think mono block is the way to go with these spkrs. For the coin a good fit might be the Odyssey Stratos & you can pick them up used for a good price.
Given that this speaker dips to .8 of an ohm at appr 33 Hz and .9 of an ohm at appr 7.2 KHz, you need a MASSIVELY powerful amp that can deal with huge current demands at both ends of the audio spectrum simultaneously. With that in mind, i would suggest looking into a Sunfire Signature with what is called their "Apogee mod" from the factory. If interested in this modification, you need to speak to Robert in Sunfire's technical support department.

I would further comment that if you were to go with an amp of this calibre and power potential, you really need to run it on a dedicated AC circuit. This dedicated circuit should be capable of providing at least 20+ amps of current. After all, if you are going to be able to produce gobs of power and current from an amplifier, it is going to have to pull sizeable amounts of power from the wall.

In the long run, you may find that your "bargain of a buy" on these speakers really is no bargain at all. They are phenomenally demanding in terms of the support components and the AC that they require in order to work their best. As far as dynamic speakers go, they are one of a select handful that can qualify as the the poster child for "tough to drive" speaker loads. Sean
I should have mentioned that this speaker stays below 3 ohms from 60 Hz and below. Given that you already need high levels of power to control a large woofer as it is, compounding that demand with a very low impedance at that point is pretty rough.

This speaker is also 3 ohms or less between 1.5 KHz and 4 KHz. There is a slight peak to 3.5 ohms at 4.5 KHz. Above 4.5 KHz, the impedance starts dropping rapidly and stays below 2 ohms up to beyond 20 KHz from that point.

Like i said, this is a VERY tough speaker to drive. The fact that it isn't all that efficient either is just more to deal with. Sean
One more bit of bad news: Infinity is not supporting these with replacement drivers any longer. On the plus side, the midrange performance is outstanding.
Well allrighty then!! I guess I will have seek out ampzilla to drive these bad boys. I'm not a quiter I will get the job done. Thanks for all the input. Stay tuned and I'll let you all know how this works out. Sean putting in a dedicated circuit will not be so bad because I'm remodeling my listening room. Thinking about getting a big Mcintosh. Anyone had any experence with the Bryston 4b? Also seen some good prices on aragon palladiums. If I find a good deal on a Threhold 500s maybe I'll give it a try. Thanks again everone.
I used a completely factory refurbished Bryston 4B on some speakers that are also low impedance and very insensitive. Not only did it not sound good, it was constantly going into clipping. I would highly recommend that you NOT use one of these amps.

There are a few guys that i've talked to from this and other forums that have Kappa 9's. Wanna guess which amp(s) they are using??? I already suggested it above. Sean
I have a pair of Kappa 9's that I run bi-amped with two pair of Carver Silver 9t monoblocks. The monoblocks run for less than $1500 per pair used here on Audiogon and Ebay. Gobs of power and one pair will run them quite nicely, bi-amping them takes everything to a whole 'nother level. I ran a Sunfire Signature with them and loss too much bass slam, so I went back to the Carver monoblocks. When I used the Sunfire Signature, I did not have the Apogee mod...that could have made a difference in the bass.

I called Infinity and they plan to make the re-stock a replacement for the bass drivers in February '05. I've seen many guys here on the 'Gon say that they have gotten the bass drivers re-foamed and they work as good as new.

good luck with your new speakers!

Check out my system here at mitch4t
I love the Kappa 9's !
Nice systm mitch I'll keep the carvers in mind. Did you need a dedicated circuit to all amps?

Sean I will also keep the sunfires in mind but I would like to find them with the apogee mods already done. Its bad enough I have to look at the Kappas now and just barely be able to drive them. antisapation is killing me.
I sincerely doubt that someone will list their Sunfire's as having "the Apogee mod" as that is what Robert Levy of Sunfire refers to them as. Sunfire's technical dept calls this their "thermal and high current update". Good luck finding used models that have this done.

As far as the Kappa's go, use what you have. Just take it easy on the spl's and you won't hurt your amp. The more that you push the volume up, the less headroom and mores strain on the amp. Too much strain on a steady-state basis with a lack of headroom results in thermal stress, distortion and the potential for the amp and / or the speakers to go "poof". Sean
I do not run a dedicated circuit for all the amps. I've never had a problem and sometimes I really crank the system.
Well the latest amp has not proven to be a winner either! I just added a McIntosh MC300 to list of ineffective amps for the big Kappas. I'm not sure if I will pursue this much futher. It might be time to find more efficent speakers. Maybe just add a subwoofer till I run across the right deal on some serious mono blocks. "SIGH" WHAT A PAIN THESE SPEAKERS ARE TURNNING OUT TO BE!!!!
electrostatics may do the job. At 300wpc it has plenty of power. Get ahold of ESL and see what they say.
Oops, meant to say check out the ESL 300 for electrostatics.
Coman61.....if you are in Southern California, I would consider buying the speakers from you if you want to unload them.


Aragon 8008 BB, high current. This seem to have been the choice for powering the Kappas in the beginning. They go for about 1000-1200, and if you can get two, you can biamp them with the Infinities. BTW, I have a pair of Kappa 9s in storage, at my mother's place and they do sound GLORIOUS, especially in the bass. I have a McCormack DNA 225 and when the time comes to move them over, I will get another amp to play with the biamping set up.
Sorry Mitch I'm in Ohio. I'm not sure if I'm gong to unload them just Yet. For now I'm just going to BI-AMP them with the Macs. They do sound nice just lacking bass. I just can't believe that the MC300 can't push them woofs. If I sell them I'll be sure to let you know. Finding a replacment is the key now that I have some decent size amps.
Do not unload them until you can get a hold of a Aragon 8008BB. Affordable and will provide you with the bass you might crave and are missing now.
Bemopti123 Thats a price I can live with. I'll give one a try. I might have to hock some more gear.
BTW, when I once had a pair of BC-2, Blue Circle Class A 75 watt monoblocks, eventhough they put out just 75 watts, the designer had recommended their own dedicated 20 amp line...which obviously I did not do. I was feeding things from a huge tube amp to other devices to the same outlet...and then, when I blew the resistors, or saw that the amp was not singing properly, I thought it was a flaw of the amp, just to later figure out that I was not providing enough amperage, watts, to the amp. It is possible that you might be also chocking the amps you are using with the Kappas. Do not put the amp on any sort of power conditioner or even strip with lights (and most likely a black transistor switch) because that will certainly mean that you are chocking off the amp from electricity. Put all amps directly into the wall receptacle. If possible, try to get yourself a dedicated amp. I think you live in a house, for the Kappas are large, therefore, something you might not have done and might be worthwhile is to make sure your outlets are "kosher" or pass the electric grade. After you are done, try the amps again and you will see. The Mac can be used for the top and the Aragon for the bottom and run for cover, you will have a good things going.

Paul from NYC
I have considered that the amps could be starving for power but I don't think this is the case. When I tried running the Adcom it was definitly the case I could see the lights dimming with the music. That was not true with the macs. It must have something to do with the audioformers. If anyone knows for sure please feel free to chime in.
Well I finally got the Kappa 9s singing. Just got a new pair of Aragon Palladium 1ks. They drive the speakers with power to spare. Thanks for the tip Bemoptil23. I'm sure all amps suggested would have done the job but the Aragons were affordable right here on the gon. I must say that these amps are very aggressive sounding compared the the Mcintoshs that I was using. Thats good and bad. The Mcs sounded more mellow and tube like but just didn't have the oomph to drive the Kappas. The Aragons are fast and detailed and take all the harshness out of the Emit tweeters. I'm happy now that I have good starting point to start building a new system. Now I need to start looking for a new pre amp amd cd player. Thanks all of you for your advice on driving the Kappas. I have the audio bug now stay tuned for futher updates on my quest for HI END audio

Glad to hear that you've finally found an amp that will tame those beasts. I would suggest looking into your preamp next in terms of upgrades. Most of the mass produced SS preamps that i've heard have a very characteristic sound to them and it isn't very pleasant to listen to over an extended period of time. Going to something that is a little more refined in this area will probably get you a lot closer to what you are looking for without removing the "punch" that you've got now. Sean
After reading a lot of the responses to your question, you might be better off just selling them. Sounds like they are more trouble than they are worth. Of course, that's just my opinion, since you have to live with the choice.
In any event, good luck.
Yes, as others have said, most Infinity speakers are VERY power hungry and the Kappa 9's are no exception plus getting parts for the older speakers can be tough. I have owned a pair of Renaissance 90's for the last 10 years and was driving them with a Threshold S350e 150 wpc and it handled them ok BUT they could have easily used TWICE that power to sound their best. I have since sold my Infinitys and bought a pair of JM Lab 946 Electra's and they are FAR superior to the 90's in every way. There is definately something to be said for efficient speakers.
I hope you got a really big amp by now.
Sorry to tell you this, but even your first amps hould have been able to drive those without frying. (Not nicely and not easily.)
Your 800 ebay deals most likley have a bad coil or perhap a few fried resistors. Better get all that checked first.
Or perhaps by now you are just disipating more heat into the cabinet.
The speakers have been tamed by the aragons. I don't think there is any damage to the speakers. They truly are that difficult to drive. The man I bought these speakers from was an older guy who couldn't have wooped on them. I know this because He was using a 200 WPC Mcintosh, don't remember the model but asked if I wanted to buy it a month ago. He also had the foam surrouds replaced just before selling them to me. This is also true because those woofers are so stiff it takes alot to get them moving. With all that being said I have to agree with most of you I should sell them because they are not the greatest sounding speaker that I have ever come across. They are however the best sounding speaker that I have owned personally. The mids and tweets are great especially with female vocals. I really can't fault the speakers or the amps just yet as they are not in an ideal envierment. The amps will need a dedicated circuit as Sean Has stated before. The room is also less then disirable. Its to small and has no treatments and I really need to get a better pre amp. All this will be addressed this summer when I rebuilld my family room. I might even do something real stupid and go for a HT in that room. At that point I will most likely have to move this thread over to the HT section for the advice of them guru's. I must say I have learned alot here in a short time and thank everyone for the great pointers. When I get my room finished I will better be able to determin If the big Kappas should stay or go. As for now I just hope that the newly refoamed woofers loosen up or a sub is going to be a must.

Borrow a pair of monoblocks from a friend and bi-amp the Kappa 9's.

As good as they sound now,.... bi-amping them will open a whole new world to you and it will blow your mind.

I dare'll never go back.