You didn't say why you wanted more power. If you're not happy with the JR, it's possible that solid state amps in general are leaving you cold. There are lots better ways to good sound than spending ever more on huge amps most of whose cost is in casework material and and machining. Get a more efficient speaker. Go with your initial impression of the Krell, which has also driven me out of dealer rooms in the past! "Fight the power."
I have very power-hungry speakers that I really love, Avalon Osiris. They image , they are musical, they have excellent balance of midbass , midrange and highs. BUT, they are power hogs and on they need testosterone-filled SS amps.I actually would try tubes, but I have my system tied into a home theater surround system and the amps are on all the time.
I have heard that Boulder or Spectral are very special with Avalon speakers. Check with Cornfedboy. He probably knows more about amp wire combinations with Avalon speakers than most reviewers.
These are very rare; 2 versions - KAS-1 and KAS-2. They were the first Krell amps to use the Auto-Bias circuit and could drive anything, including Apogees.
The KAS series amps, to me, sound much better than their current line. The current line of Krell amps are not as tough as they used to be, because the trend in speakers these days in high impedance and easier to drive (ie, Avantgard Horn vs Apogee ribbons).
I have had Wilsons with Mark Levison gear run me from the room, I'm not sure the Krells were necessarily the problem there. I have owned several Krell amps over the years. My current one is a KSA 250. Before that I had a pair of the KMA 100 mkII, and before them a KSA 50 mkII. So you may guess where I'm headed. I like the Krell amps, but not all of them. The KSA 50 and the KSA 250 are considered to be two of the best amps they ever made. I like the pure class A power and detail, and their bass cannot be beat. I have not liked the S series amps as much as the KSA series. I'm now auditoning a FPB300. The FPB is much more open and detailed than my KSA 250, but also, so far, seems lighter weight. The bass is tighter than the KSA but not as dramatic.
Like any other component, it will depend on other equipment, the room, and your tastes. There is no perfect anything out there.
Class-A may not be the right thing for you if the amps are on all the time, they will generate a lot of heat (they are not proper Class-A if they don't).
But there must be something wrong if a 350W Jeff Rowland amp isn't enough. I would try other options, remember that the Krell only gives you a 3db upgrade.
I have a Krell KSA-250 (1993 vintage). I could not be happier.
I believe it compares very well to the best out there. Of course you need dedicated AC Lines atleast 20-30 amp line. It draws 12 Amps at idle.
And I am using the Whale Power Cords and PS Hi current power port.
It also can warm a room up considerably.
Man Osiris those things are huge, if you can swing them(the osiris) go for the big boulder mono's. I have the snot that came out of the nose of the osiris(eclipse, avalon) and enjoy them very much with tube power but you would need some HUGE tube amps to handle that set up. What do you use for surrounds? Eidolons?
lol. but seriously...if anyone here IS using eidelons for surrounds, i will personally drive to your house and kick your a$$ for free. email me.
Hi all, I appreciate your comments. I'm currently using Jm lab Mini Utopias for surround with a center Utopia. When I get my own room in a year or so, I will switch to Mezzo utopias.
Dare I ask why you use a center? Not really why you started this thread but I doubt that the avalons need it if set up properly. If anything the center utiopia is probably hurting the sound. How many people does it take to move those things? its gotta be about 6 at least! Don't the cabinets weigh about 1000lbs each? I used to dream about them till I realized that I would have to move so they would not fall through the floor! Where is that overly cornfedboy any way?
The center is for home theater only. I can't set things up optimally until I get one of the rooms in our basement, thanks to my wifes sensibilities. The speakers aren't too heavy, but the crossovers, which are separate, weigh 500 pounds apiece.
tim: don't be gettin' too excited. the osirises (now replaced in the avalon line by the sentinels) do weigh a half ton crated but are comprised of more than two "parts."
david: i don't think you'd be happy long-term with krell amps on your speakers. any of 'em. if class a intrigues you, i'd suggest goin' to a boulder 2060. 600 watts of pure class a power into 8, 4 or 2 ohms. i'm sure the guys at goodwin's highend can arrange an in-home demo.
i leave my tubes running 24/7 anyway. nice system . i would love to hear it. why the mixture of jm lab and avalon?
I am always amazed at how everyone on this site loves to trash Krell. I have owned the KSA-250 which is a good amp, but very lean sounding and a heater for the room it is in. I auditioned the Rowland 350 watt mono 7's at the time I had the Krell 250 because I had the Consummate preamp and I was disappointed in the sound and bass control. Rowland ran out of gas on anything played loud. I bought the 300FPB and it sounded more musical than the KSA250 and to me, just as detailed and controlled in the bass. In my mind, nothing comes close to the FPB600 in terms of sound and effortless power when it is compared to the past Krell stereo amps and other solid state for that matter. I recently upgraded to the Krell 650mc's connected to the KPS-25sc playback system with the CAST cable from Transparent (kills my Transparent Reference interconnects and only cost $300) driving the Wilson MAXX. The mono's are incredible. I will be honest..Krell is not forgiving of a recording. If it is a good recording it sounds unbelievable, a bad recording sounds bad. Sorry, that's the way it is. If you want to hear what's on the recording you will hear it. Most people don't balance the equipment to the level of Krell quality and will never hear what it can do. It is only bright sounding because of poor cabling, poor front end or bad source recording. I was in the Analog Room in San Jose, CA listening to the Nagra tubes stuff driving the Avalon Eidelons. The front end was a VPI turntable with great cartridge etc. and frankly, that sounded brighter and harder than the Krell. It drove me from the room. So my only recommendation is to bring it home and listen for a week. I could have bought anything and I bought Krell because they build great stuff.
If I had bottomless funds , I'd go for the Boulders in a flash. As it is, I buy virtually everything on Audiogon at 30-50 % off retail. Find me some used Boulders at 50% off and I might take the plunge. Anybody used the Pass X-series?
One of my regrets in things audio (and we all have them)is selling my KSA-50 II amp. This was a brash, kick ass & take names no apology amp that worked great with my Apogees. But alas, being an audiophile, I sold it for another amp. Big mistake. I've owned a KST-100 (didn't like)and a KSA-150 (nice, but a little....uninvolving).
I've heard from ears that I trust that the KSA-300S is a good amp. However, that "little" old KSA-50 was engaging as all get out and had that toe tapping swing.
My current amps are the keepers and are made by Reference Line (Silver Signatures with the high current, outboard power supplies). They have the grace and bloom of a good tube amp, the grip of the best solid state and the swing of the KSA-50. Hard to find, expensive, expensive to run (each amp is rated at 100 watts, 8 ohms and is class A biased all the way to clipping into 2 ohms) but they are worth it. I find that the solid state stuff that is HEAVILY biased into class A sounds the best, especially at low levels and with a glass of 18 year old single malt scotch.
To make a long story even longer, Krell HAS made some great sounding amps. You just have to pick and choose and don't be afraid to look BACK into their model line. Good luck in your search and choice.
1953, you and me both wish we'd never sold those KSA 50 amps! That was my first high-end amp, and easily the sweetest amp Krell ever made, as well as a powerhouse belying its power rating. I agree with you that certain of their older amps (the KSA 50 Mk II, the KSA150, 250 and MDA 300s and the KAS amps) are very nice sounding amps that can drive anything out there; as far as comparisons with other amps, it will ultimately come down to personal preference. Be worth a listen in David's setup, and I'd love to hear it. I must note that Kirk leaving those huge Tube Research amps on 24/7 must essentially eliminate the winter heating bills! But Kirk, what do you do in summer?
I had a krell FPB 300 and was very happpy with it. I used it to drive Magnepan 3.5R's. I's still have it except I decided to go with a tube amp. Buy the Krell used if possible. Save about half and still get a great product. Buy as new as you can to get some of the transferable 5 year warranty
I Have a Pass Labs Aleph 4 (100w pure class A watts/ch) and really love its natural sound. I would defintely try a Pass amp. I think I saw some 1.2 monos and there are several x amps out there.
i run the ac and ceiling fan in the summer. it really is not that bad. i have an old house with tall ceilings as well. i hate the tall ceilings right now but love them in the summer. i have owned the krell ksa 250, 200s, 300s, and have a kst 100 strapped to a pro sub in my theater. i also had the md-20 and studio. i love krell. i just think if anyone hears the right tubes in their own system the journey will end. i was hard headed myself. it took me a long time to just shut up and listen to the music. i agree that krell will let you know whats on the recording .garbage in garbage out. ok fine most recordings sound like trash. i hear much more detail with my tubes then any krell. krell gives a cardboard cutout soundstage. good tubes make you forget about speakers, amps, preamps ,etc, and makes you feel you are there. audionut you sound just like me a few years ago. i did not want any stupid tubes, i wanted accurate to the t. but i now no what that means. i dare you to try good tubes as you will be praiseing them as most of the audioheads on this site. same goes for all you other ss heads. as i said i was mr krell for a while. good luck guys and gals.