Help power pair of Infinity Kappa 9's please

On the other hand if you find an Audio Research M300 you might be in heaven. Arnie has developed the Kappa 9's with that amp.

I have to add that Mitch is right here.

if you do not biamply and put a Threshold S/1000 or SA/2 in front of them and use a good tube amp Audio Research SP11 or solid state Threshold FET 10e or 11 or SP15 this loudspeaker is going to blow you away!

They are real life keepers if you do not have the room for the RS-1, Gamma's or Betas.

It depends on what you want and what your financial straight is. Any high quality solid state amp will do the job.

I would recommend that you try new amps, becouse they easily surpass the preformance of the loudspeaker.

I can recommend the Modwright KWA150 one amp or if you have to money you can use a pair to drive the Kappa 9's.

If you biamp I would certainly encourage you to use a vaccum tube amplifier for the midrange and tweeter like the older Sonic Frontiers Power 2 or Power 3. If you use another tube amp, make sure that the output transformer has two ohm or one ohm windings.

To make it sound that good you might spend not less money, becouse the amps I mentioned are not really cheap at Audiogon.

@Rrog:
Most people believe the sound of the amplifier will be degreated becouse of the 0.78ohm load. However, some people met Arnie and he always pointed out to use tube amps, becouse they changed the sound and linearity dramatically due to the impedance cruve.
They will sound better will any high powered solid state or tube amp. It is absolutely incorrect when a power amp can deal with the load that the sound will be degrated. This loudspeaker can react extremely fast and with the right amp I beleieve there is no loudspeaker down to that price range that can play in the league.
I have already heard loudspeakers in the 100 000$ league but it seems that alomost none can come close to the Kappa 9's.
If you have built them up new, remove the polyswitches you will hear what this loudspeaker can really do. I have already heard the Genesis 5 and that loudspeaker is close to that.
I have tube eletronics and solid state eletronics and I have never heard anything that could beat a Kappa 9. They may only be topped by Genesis and the RS-1 or IRS Series.

I have to add that since some years I tried different combos.

If you do not biamp a very high current like the old Threshold SA series is a must. They sounded best at my home with the SA/2 monos.

Still the best sweetness and natralness came with an Audio Research SP-10 preamp as well as with an Counterpoint SA-5 or SA-5.1.

For costs I am not biamplyfing but I have a total of 56 kg power amps to drive them and they sing very beautifully.

I have tried different biamping suggestestions also with tube amps but sooner or later I came back to the SA/2 monos.

Only if you use very expensive tube on full range it will sound better like the Audio Research M-300, Conrad Johnson Premier Fives and of course a VTL Deluxe 300, nothing really very cheap of course.


You might still get the best results with biamplificatio or if you cannot biamply use very high current designs back from the past.

I have to add that not any biampliciation sounds best. You need to try and find it out.

Biamplication however with very good amps is less necessary if you have a killer preamp.

I hope this all helps. Long time no discussion here!

I agree with George and again to tomlab.

The speaker was developed in conjunction with Audio Research M-300 amplfiers.
However Arnie used the SP-11 as a pre and various Threshold models to drive them full range.

For you info the Adcom wont do the job. The Kappas 9 impednace is below 1 ohm in the mid and highs and at the woofer region producing phase angels with minus 70 to 80 degrees. This is near a total short.

Therefore biamplfiying takes aout the stress produced by those angels.

I agree with micthforte that only very high current designs should be used and lower powered amps like the Adcom wont do it. The Parasound works quite well and if you have alow budget you might go for it, but do not expect that it will sound like Audio Nirvana.

For full range I would go with the big Threshold SA series and agood vaccum tube pre or an CJ Premier 5, Audio Research M-300, VTL Deluxe 300 or a McIntosh MC 275.

If your really low on bduget you can go with the Parasound I still would use a tube pre.

Should you ant to biamply you will need a Goldpoint stepped attenuator for matching the gains.

You can use the Prasound for the whole speaker, later use the Parasound for the bottom and apply a tube amp for the mid and highs. You need a seperate passive preamp for matching gains like the Goldpoint stepped attenuator.

Another soloution would be a Mark Levinson No.23 for just 2000$ bucks and use a tube pre like an Audio Research SP-6B or SP-8.


The Martin Logan CLSII does not produce difficuilt phase angels like the Kappa 9's and therefore they are much easier to drive.

I have experienced myself that a lot of money is necessary to keep the speaker work properly and if it is too expensive an Infinity RS2b has much lower requirements.

On the other hand for costs you could try two Threshold SA3, Two pairs of Carver Silver 9T's, two Threshold S300 or a Mark Levinson No.23.

The best results I have gotten with tube /hybrid preamps. If you cannnot afford expensive ones try Audible Illusions Modulus3 or Mfa Magus.

I hope this will get the hassle out of bad reviews.