amplifiers for Kappa 9's

Unless you get an amp that can provide massive amperage, you will fry your Kappas. The best seem to be old Aragons, I think the 4004 or was it the 8008BB, my memory fails....they were designed by Krell. They continue doubling down to less than 1 ohm...very few amps can do this.

I am a little apprehensive of the Parasound 3500...some owners reported problems with humming transformers.

No digital amp, especially those with questionable power supplies will ever, NEVER, drive these beasts. It was commented to me by Rick Schutz from EVS, that digital amps have terrible power supply sections, they are overrated in the specs.

Go with the heaviest hitting SS, preferably Class A or similar that is heavy, especially to power the bottom.

The top, I would also recommend decent power.

Finally, make sure you can committ to spend some money in dedicated powerlines for the amps to run the Kappas. The harshness that you hear has a lot to do with current starved amps.

There are some mods you can do on those Amp Killers, cabling seem to be common to be exchanged and some people also talk about better stands than those pathetic slabs of MDF or something.

Decent, massive power and enough current is the key.

BTW, I have a pair of parked Kappa 9s that have been in my mother's garage for the past 16 years...mint, boxed sets.

The Kappas are amazing for what they do, and something similar to them today would go for $$$$$ more. Once you get them set up properly, very few speakers out there can do what they can. The last batch of speakers designed by Nuddel? who went on to found Genesis...see what the Genesis cost, ouch.

There's an Agon member here running two Sunfire Signature's for his Kappa 9's. At the low impedances that these speakers present, he has 1200+ wpc for the top end and 1200+ wpc for the bottom end. These ratings are based on a 4 ohm load. If you wanted to consider this speaker closer to a 2 ohm load, which may be somewhat conservative over much of the range of operation as it drops to below 1 ohm i think, he's got 2400+ wpc for the top end and 2400+ wpc for the bottom end per channel. This is without bridging, so damping factor is not compromised.

Having said that, i don't think that two ZR1600's could do the job here. The limited testing that i've seen on these amps wasn't very favourable. Most all of this can be found in the archives though as this speaker is notoriously hard to drive, hence the subject coming up a couple of times before. Sean
>

Bemopti123
Are you sure about Digital amplifiers not ever never being able to drive such a load? Those are pretty strong words my friend. I know some of you fellas are from that old school.I seriously doubt an amplifier like the Carver ZRx3200 would have a problem driving these speakers. I've come to realize Paul you really dislike Carver products.
Even though these amplifiers aren't under Bob Carver's name, you seem to associate the two. Carver pro is a different company. I would love to see your face with this amplifier hooked up to those speakers. I guarantee you would have to eat those words! These amplifiers do use toroidal transformers if you didn't already know. Here we go again with the generalizations.

I'm so glad you mentioned Ric Shultz. I contacted him sometime back about his Beta amplifier which uses ICE power modules. Guess what power supplies it uses.. switching power supplies! Here's a qoute from his website.

Dual mono (each amplifier module has its own separate power supply). These modules use switching power supplies. Some people feel that switching supplies (like Peter at Acoustic Reality who uses linear supplies with his modded Ice Power modules) are less good than linear supplies.....then there are those who feel switching supplies have advantages over linear supplies.....My take is that whatever type of supply you use, it must be tweaked or you have no idea of what it is capable of. The stock Ice Power module sounds....well....lets say zippy and two dimensional.....after our tweaks and mods the module is perfoming better than the Ice Power modules that we were using that use linear supplies....these tweaks were to the power supply and other things. What matters in the end is how something sounds....this is what you guys will determine.

Either you or him isn't telling the truth. Which one is it?
Quoting from the great Homer Simpson..DALT! LOL

Here is the impedance curve for the Kappa 9's.

http://f4.grp.yahoofs.com/v1/wLtQQtJS003JLQWVCsufEZM95gi5uACVW5ItP_G1a7hnt5eNa9-cVaCZNzyLVt_QjjNhT1i1M2Bt-JMajpCYlvqVDszIGdxD/Infinity%209%20Kappa%20Impedance%20Curve.jpg

John Curl measured a Carver Pro ZR1600 and it was so distorted at 180 wpc @ 8 ohms, that he was afraid to push it any harder than that. Much of the distortion that he was seeing was high frequency artifacts from the very poorly designed power supply, but none the less, the amp wasn't performing up to rated spec. Since most amps produce measurably more distortion as impedance is reduced, trying to run such an amp with a very demanding low impedance speaker would only aggravate the problem.

From what i know, this amp was given to him by Brian Cheney of VMPS to test. Brian had verified that the amp was working and sounding "quite good" when Curl received it. As such, one can only speculate that this wasn't a defective model or anything like that.

Supposedly, "Carver Pro" ( who is reallythe car stereo company known as "Phoenix Gold" ) have made some design revisions to these amps based on "audiophile feedback". Given that i've never seen any follow-up on the amps after that point, i don't know if they will actually meet and possibly exceed spec or if they are still in the same boat. As such, buying another model that is rated for more power from Carver Pro may get you more power, it may not actually get you the amount that they are rated to produce with a reasonable amount of distortion. This is strictly conjecture on my part though, as i've stated that i've not seen any further follow-ups on this brand. Sean
>