Help power pair of Infinity Kappa 9's please


Hi all!
I have a pair of Infinity Kappa 9's:
Nominal Impedance: 4 to 6 ohm
Power Rating: 60-340 watts RMS
Efficiency: 102 dB SPL @1 watt, 1 meter
Crossover Frequencies: 80Hz, 800Hz, 4500Hz
Frequency Response: 29Hz-45kHz +/-3dB
Physical Attributes:
1x - SEMIT Supertweeter
1x - EMIT Tweeter
1x - 3" Edgewound Voice Coil Polydome Midrange Driver
1x - 5" Polypropylene/graphite Diaphram Polygraph
2x - 12" Cast Frame , L/C Tuned Woofers
Dimensions: 59.5"H x 21.5"W" x 8"D

My room is 12'x12', I have $2500 budget and would like to play music off my computer. I need amp(s), a preamp, and a DAC i guess (is the DAC necessary at my low of a budget range?). I know my budget is low so I will be shopping for very used/old equipment. If anyone has any experience, suggestions, or words of wisdom, they would be very much so appreciated.
Thanks,
JT
jtiesel2
I think with all the naysayers in this thread, it's worth mentioning that there are two modes for the Kappa 9 woofers to operate in:

1. The "extended" mode, which is the "amp-killing" mode that goes down to 0.8 ohms.

2. The "normal" mode, which puts a 1 ohm, 50 W resistor in series with the woofers - thus raising their impedance to levels more like the Kappa 8.

I used an Adcom GFA-555 to power my Kappa 8s - and I was never for lack of power or stability. The only time I ever blew a fuse was when running a 20 Hz test tone at obscene volumes - and it was the power supply fuse, not one of the output fuses.

You could almost certainly power the Kappa 9s in normal mode with a 555 (or any other similar amp) as well - leaving you a good $2200 or more in the bank to save for an amp that can run them well in extended mode. Until then, you can party hard with only slightly less bass.
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.
own kappa 9s run them with a bryston 4 nrb and bryston pre amp and 2 powered subs. Have the speakerers set on normal on back which reduces the low end while keeping everything else same. This makes the amp use less power making it more efficient. This is were the subs come in to pick up the lost bass. This made a HUGE difference. Have looked to trade in the kappas but havent found anything yet that sounds the same even at 3500+ but this is just my opinion what ever sounds good to you is the way you go.
I'm quite happy running my K9's with a pair of Threshold SA/2 monos. 100w/ch but plenty of current. I have run the speakers with a pair of Threshold S/500 II's in bi-amp mode as well and honestly the SA/2s sound way better.
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.