Kappa 8 and AA-1800

Zyrzox

New Member
I have a chance to pick up a pair of these beasts locally. Supposedly they're in excellent condition though I have yet to see or hear them. My question to those of you who are far more familiar with them than I - would my HeathKit AA-1800 have any trouble driving them, or would I be better off running them bi-amped?

Any input would be greatly appreciated...even if just to tell me to keep looking for something that's easier to find parts for.

Thanks in advance!
 
They're amazing speakers, but a difficult load with very low impedance dips, especially with the woofers. Bi amping would be a strong possibility, with a good high current solid state amp on the woofers.

Make sure the mid ranges are in decent condition, as they are hard to find replacement parts for.
 
They're amazing speakers, but a difficult load with very low impedance dips, especially with the woofers. Bi amping would be a strong possibility, with a good high current solid state amp on the woofers.

Make sure the mid ranges are in decent condition, as they are hard to find replacement parts for.

Thanks for your reply, J.

I've been reading everything I can find about the Kappa 8's and that's why I posted my question. The amp I want to drive them with is rated at 250 WPC (but is really closer to 350) at 8 ohms. +/- 110v DC rails, purportedly capable of peaking to a kilowatt, with 8 output transformers per channel. Obviously, more is better...but how much is enough, and what really constitutes "high current?"

Everything I have read about the Kappa's (which you also reinforced) indicates that they dictate quite a dynamic load with a ton of juice in reserve...and while I suspect that my AA-1800 might be up to the challenge, I'm still hoping that someone who has previously married the two might chime in and comment along the lines of "sonic bliss" or "smoke and ruin." If I end up buying the Kappa's (to replace my trusty ESS 1b's that have been in constant use for decades) and they seem like they need more oomph, I'll start shopping for another amp - most likely an SAE - to drive the lows.

Thanks for the heads-up on the Polydomes - I am aware of the potential deterioration issues with the mids and will pay special attention to their condition when I go to audition the speakers this weekend. I intentionally didn't ask the owner what he drives them with so that will be interesting to discover...but from what he claims, they are in excellent shape, cosmetically as well as functionally. Needless to say...I'm pretty excited!

Thanks again for your reply and happy listening!
 
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.....8 transistors, right? 8 transformers would weigh a ton!

D

Yes, duh and lol, 8 transistors...not transformers. Really silly of me to try and post something meaningful first thing in the morning before the caffeine has kicked-in.
 

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See this review, particularly on the second page they discuss the impedance curve: (link removed) 1.3 Ohm at 40Hz, between 1.3 Ohm and 4 Ohms from 20 Hz to 250 Hz. Then 9.5 Ohm at 1000 Hz, and then nearly constant 2.4 to 2.8 Ohms from 1.8 to 10 kHz.

So even Kappa 8's are quite a difficult load (compared to Kappa 9's, which are even worse).

This review and the associated impedance curve details are very helpful, Seppo. Thank you for taking the time to share this information with me/us.

Indeed, these speakers seem to be very unique in many ways, not the least of which being the power requirements to truly bring them to life. I'm going to have a chance to hear them either tomorrow or Monday evening, being driven by an Aragon 4004 mkII, and I am really looking forward to it.

Chances are I won't return home empty-handed, either. An audio engineer acquaintance of mine with over 40 years expertise thinks the AA-1800 has enough horsepower to drive these speakers without serious issues. And if I do end up frying things, well...then I guess I'll have to find a replacement with a bit more of what it'll take to ensure that I don't make the same mistake twice.

Thanks again for the info!
 
Please tell us how it goes. Some of us love a good classic Infinity Kappa discovery story.

Not so sure my story merits being considered classic but I'll give it a shot. I must admit that before I saw these 8k's for sale locally a few days ago, I hadn't really paid much attention to Infinity’s offerings. I've been content with my four vintage ESS speakers for quite a while, and felt that they met my needs just fine.

My interest and passion for audio equipment began when I was assigned responsibility for hooking-up my family's new Superscope receiver in the mid-70's at the age of five. I had been running the 8mm projector for home movie night since I was three, and causing general electrical and mechanical mayhem at home and in public places (always taking things apart, flipping switches and pushing buttons whenever presented with the opportunity) since about the same age, so I guess I got a bit of an early start. After years of tinkering with a wide range of receivers, amps, components and speakers I never lost that sense of wonder and awe over the possibilities that exist…which brings me back to the events that transpired these past few days.

I spent a couple of days reading about the Kappa series, of the numerous testimonials to their capabilities and sonic virtues, and was intrigued to say the least. I made an appointment with the seller and went to audition the speakers at six thirty last night. We met at his house, I followed him downstairs to the (concrete) basement and told him that he should pick what to play for my first listening experience; he chose live Alice in Chains. The speakers were placed about 8 feet apart, roughly five feet from the back (cinder-block) wall, and a comfy reclining chair was placed about five or six feet to their front and center, but I didn’t sit down.

My initial impression of the speakers was, overall, quite positive: they were as visually striking as I was expecting, and they definitely produced a very solid and dynamic soundscape as the tunes began to pour forth. I thought what I heard was a crunchy flaw in the mids on the right (which he insisted was intentional and was just how that guitar sounded) so I suggested that we move on to Floyd…which sounded fantastic without any crunch…and then he put on some Tower of Power. I really liked what I heard but I wasn’t quite as overwhelmed as I had expected to be. Nonetheless, my mind was already made up. Did they sound better than what I was accustomed to? Definitely. Did I want to take them home with me? Absolutely!

The sequence of events which followed occurred very quickly: tweeters, domes and foams were scrutinized, an offer was made and accepted, money changed hands and suddenly I was on my merry way home with my new speakers safely packed into the back of my Jeep. I glazed-over after the money was exchanged, though I do remember being spoken to and replying – I was just too busy envisioning everything that would have to happen next. The drive home is a blur even though it was only last night.

Upon returning to my house, disconnecting the ESS', unloading the 8k's and hooking everything up...I decided that my inaugural "test" song would be Dire Straits’ "In the Gallery." I dialed the volume knob on my preamp to 50%, sat back in my chair and let 'er fly. Almost immediately I went from feeling a sense of fear and cautious optimism to being utterly overwhelmed with, and in awe of, what I was hearing! The sheer detail and brilliance of the music flowed over me, enveloped me in its luxurious, velvety embrace...commanded my attention and earned my respect. I wasn't expecting to be so completely blown away from these things, but I was (and probably always will be every time I fire them up). I suspect that getting the speakers out of the concrete basement and into a proper room is what really brought them to life...and this bodacious amp probably doesn't hurt, either.

I couldn't sleep last night from the excitement of what lay in store today, finally couldn't take it anymore and got out of bed at five this morning to resume my experimentation and adulation. The only real experimentation I've done, though, has been to switch between "expand" and "normal" modes. The presence controls are all set to flat. I don't have any EQ between my source and the amp. I haven't gotten it back up to 50% on the volume knob like it was last night...and don't really feel the need, though I'm sure at some point I will be tempted to push the envelope of what's possible with having these speakers married to this amplifier. There’s no distortion whatsoever, no sense of over-driving or starving anything…and while my amp seems to be slightly warmer than it used to be, as expected, I’m satisfied that it’s in no danger of self-destructing.

Thus far today I have sampled some of my all-time favorites: Alan Parsons Project, Brian Eno, ZZ Top, Tangerine Dream, Amon Duul, Gary Numan, Shadowfax, Jean-Michel Jarre, Genesis, Jethro Tull, King Crimson, Zeppelin, Kraftwerk, Yggdrasil, Shpongle, Moody Blues, Steeleye Span, Thomas Dolby Yello and Peter Gabriel. I’ve only scratched the surface and have, beyond any shadow of a doubt, already been able to discern new musical components and quite a few flaws in just about every track. I can’t believe how much of my favorite music I had been missing! I can't wait to (re)listen to everything in my library...and discover a whole bunch of new stuff that I don't even know about yet! My infatuation with and love for music has been reborn and I have these 8k's to thank for that.

So that's it from me, for now. Not much of a story, really. Just the tale of a very fortunate geek who is one step closer to finding that ever-elusive sonic perfection that he's been chasing after for decades. I can only begin to imagine what other technological wonders the future holds in store and have no no doubt that it's going to be fun finding out.

Happy listening, y'all.
 
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@BK, Do you mean Ontario, or....Finland where I am originally from (Seppo is a common Finnish first name). Either way, the climate is the same :)
 
Not so sure my story merits being considered classic but I'll give it a shot.

I didn't assume your story would be classic but it turned out that way. A well written story of Infinity discovery by someone with great eclectic taste in music. It's gratifying to have you join us.

I meant the Kappas are classic Infinity. The RS Kappa series is from the back end of the period in time Arnie Nudell was with the company which usually defines the classic Infinity era.

Be sure to gather the information you need to take care of the Polydomes. Keep them away from sunlight, especially direct sunlight. Search AK for the keywords "Meguiar's" and "Polydomes." Prevention and maintenance is far better than having to seek increasingly rare and expensive used replacements on eBay.

Would you please explain your avatar? I'm trying to figure out what exactly it is I'm seeing. :)
 
@BK, Do you mean Ontario, or....Finland where I am originally from (Seppo is a common Finnish first name). Either way, the climate is the same :)


I grew up on the St. Lawrence river...Ogdensburg NY...

the climate=frigid...
 
I grew up on the St. Lawrence river...Ogdensburg NY...

the climate=frigid...

I like having four seasons, real winter, real summer. And nothing beats hot wood fired Finnish sauna steaming at @200F and dipping in the icy lake to cool off when it is 0F outside, repeated for a few hours :thmbsp:
 
Thanks for your kind words o' welcome, all...!

And Newk - thanks for the suggestions concerning the prevention and maintenance options on the Polydomes; I'll see what information I can dig up and will probably be back here asking for guidance sooner than later. I'm intimidated by the prospect of applying any sort of chemicals to them but they are yellowed and, though still supple, certainly showing signs of their age.

As for my avatar - it's just me, with [what's left of] my cyberdelic brain-stuff oozing out from my eye after a particularly savage night of searching for answers to some of life's mysteries...many years ago...
 
All I have to say is that investing in these speakers was the second best thing I have ever done for my listening pleasure...trumped only by the acquisition of the Heathkit gear that's driving them. Five days in and I'm still waking-up every morning eager to hear the click of my relays and giddy over choosing what I'm going to listen to next. The sheer fidelity these speakers produce is nothing short of breathtaking and I could not be any happier with my system!
 
All I have to say is that investing in these speakers was the second best thing I have ever done for my listening pleasure...trumped only by the acquisition of the Heathkit gear that's driving them. Five days in and I'm still waking-up every morning eager to hear the click of my relays and giddy over choosing what I'm going to listen to next. The sheer fidelity these speakers produce is nothing short of breathtaking and I could not be any happier with my system!

Man, that's seriously heartwarming. :beerchug:

Imagine drooling over the Kappa series set up side by side in the late 1980s showrooms. The only drawback was knowing they were too expensive for a lot of common folks. Those 8 Kappas you're loving cost upwards of $2k back then. Put a current dollar value adjustment on that and think about what a bargain you got because you waited 25 years. ;)
 
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