Krell primer?

I was hoping some folks could give me a primer on Krell amps. I’m in perpetual upgrade planning mode and have seen a number of Krell amps coming through A-Gon. I thought I’d ask for opinions. It seems that the FPB and KSA lines, which I gather are at least ten years old, are relatively reasonable in price and seem well respected. Can anyone comment on their sound? How much heat do they throw? Are there any ongoing maintenance issues with the older amps? I understand Krell still services their older gear, much the way McIntosh does.

Any comments would be useful. Thanks!
I purchased a KSA-150 many years ago new.
I just recently sold it on ebay for well over $1,000.
A few months before I sold it, I called Krell to see if they still serviced the 15ish year old amps. "of course" was the answer.
I really expected them to laugh at me and suggest I buy a new Krell.

The unit went to Krell, got a refurb job...and it came back good as new.

Over the years I've seen dozens of opinions of the old Krell Amps...pretty much love/hate. The KSA-150 was a brute, built like a tank. Pure transistor sound... Very little if any character to the sound in my opinion. I fed it with a tube preamp and was extremely happy. If you're looking for a bit of mellow to be part of the power amps character, you'll probably not like the old KSA's.

If I were to state a few words on it's sound:
dead solid bass
on the dry side
probably 2nd harmonic distortion

UPS managed to drop the KSA during shipping and all 4 feet got sheared off! I dismantled the thing for repair. Krell amps are built extremely solid. My new $5,000 amp from another manufacturer, while being well built, is not in the same class as my old KSA.

If you locate an old KSA in good working shape, I can't imagine how you'd be disappointed, unless of course you are looking for it to exhibit a specific sound character.

My KSA got plenty warm, but it drove my Maggie 3.6s fine. On a hot summer day with little air-conditioning I used to worry about it, but it never exhibited anything other than good solid performance.

Good luck
The FPB series of amps were Krells pinnacle of design in regards to musicality. The FPB600 is a classic amp with complete control combined with amazing tone color and texture, rivaling many high powered tube amps, minus the problems. Even up to the 700cx series, the amps are musical, extended and full of color and life. They run hot and need good ventilation, but rarely give you any problems...none of mine ever caused a problem. Dollar for Dollar, they offer a value unsurpassed in the high end used marketplace.
You are better off with old Krell amplifiers than preamps. Generally speaking they are much cheaper to fix. If you purchase any Krell product older than 10 years old you should plan on having it serviced. The old preamps can represent well over a thousand to repair.

The other thing I have noticed with Krell is that younger people seem to like them more than older people. I was a Krell dealer at one time. It is excellent equipment, but does it have the sound you want. Good luck.
The KCT with a FPB300 or higher and the right associated equipment would be wonderful.
I've had the KCT/FPB400cx combination since early 2003 and I have no desire to upgrade these components, though at times I must admit I've wondered how much more of everything I would get with a 700cx. These components have improved sonically through the years and have worked perfectly for well over 6 years now. I would go with the FPB cx series of amps if I were looking. Also my experience is that they don't get too hot when running at nominal levels; at 80-85db from my speakers (Thiel CS6) I can still hold my hand on top of the amp.
i have the fpb600c and have since new around 2003. it has always functioned perfectly and really sounds better now than ever. rayoo's description is pretty dead on. fast, clear, powerful, dynamic and did i mention the bass? you will never want for more bass impact...ever. kick drums feel like body blows. i like em. i will say equipment matching is important with krell as cables are. i sort of tame mine with cable choice.

i do not find the heat to be excessive but they will significantly raise your power bill. seriously.

it should be mentioned that they are very large and very heavy. the build is outstanding all be it somewhat over built. i store canned food in mine in case of nuclear attack, i plan to pop off the top and drag me an my dog in for shelter. i do feel bad for my wife but really not enough room...
Richard stacy is utilizing his Krell to the fullest it seems...well done sir, well done!
Thanks for all the great information. Can anyone tell me what pre-amps they're using with their FPBs? Anyone using a tube pre? I want to build detail, but not brightness or harshness. For that matter, what cables?

for cables i use older mit comparable to the oracle line today. speaker cables are mit mh850 and interconnects are mit 350 proline reference. both can be had for pennies on the used market compared to their original value (and performance). i find these cables add a more natural flavor and tame some of the big krell's aggressiveness. i am actually in search of a preamp so i do not have any input on that match. i have been using my theta processor which has been adequate but not the best overall preamp mate.
I use Harmonic Technology throughout.
I currently own and love my Krell FPB 300-C. I upgraded from the FPB 200. Obviously the C and CX versions are the newer/newest versions of the FPB Series. That being said, I never had a hick-up, concern or any issues with the FPB 200 (before upgrading). My FPB 300-C has performed equally as reliably. I have owned other Krell equipment as well (preamps) and only once had a problem with one much older preamp a while back.

I do make a point to contact Krell, sometimes even speaking with Dan D. directly. They are always happy to answer any questions and even make suggestions. My local Krell dealer is terrific (shout out to Larry at Paragon in Ann Harbor). Other than with one Preamp, my calls to Krell have always been unrelated to problems (as referenced above, never had problems with an amp of theirs).

For the sound? I love the FPB Series. I have also listened to the KAV Series and there is no comparison, FPB is MUCH better. Only thing I would say is that if you are buying an amp that is more than 15 years old, I would inquiry about what parts have already been replaced. It should be at least 15 years before any parts normally need to be replaced in a Krell amp.
I currently own a KSA 100MKII and 2 KSA 250 amplifiers which are in pristine condition (2nd owner).Preamp is a KRC-2. Only issue I've had was the baby 100 popped/shut down shortly after turn on 10yrs ago. Living in PA. made it possible to drive to Krell in Conn.,in which I received the full tour!! Kudos HAVE to go to DAN D. for having an extremely NICE and PROFFESIONAL staff!! A capacitor in the protective turn on circuit went bad,$128.00 repair. Went bad due to age/not run on a dedicated line. I STRONGLY URGE installing dedicated lines for your equiptment especially if considering a Krell amp. Yes they are older but I still love their sound. Electric bill isn't too bad for the price of happiness and they do run HOT but, built to stand the test of time!!! Good Luck !!!
I have had the FPB-450mcx amps for 3 yrs now and love them. the heat will grow as the volume is increased. One of the amps needed to be returned for repairs because it would over heat and shut down on it's own. It works perfect now.
I have a pair of KMA 400,s contacted Krell service. they quoted $1000 U.S for service.My problem is I,m in Australia and the freight scares me. Does anyone know of a trustworthy Australian tech that does old Krells up.
I own a Fpb600 that has served me very well, not a single problem for almost ten years. Before that I had KAV series amps, but they were nowhere near the 600. Subjectively I even wonder if it sounds better over time (but this may be due to various accumulated tweaks). I especially like the layered deep soundscape with several things going on at the same time. A separate mains line is very much worth it. Also, the Aesthetix Io with volume, direct (balanced) to the Krell, is a great match, much better than with the KAV preamp I had.
I use the following Krell amps with great success: 2 pair of KSA 250 & 1 pair of MDA 300s. They sound great with Signal Cable Silver Resolutions interconnects, Ultra Speaker cables & power cords. I like the KSA series better than the FPB series. I do like the EVO series. You can always count on the KSAs to bring you themusic. Now I'm using thr ARC REF 3 preamp, Legacy Helix speakers, and the PS Audio Perfect Wave DAC and transport along with the Power Plant Premeir. They do heat up the house a bit. Even if you have to rebuild the amps the KSAs are a great buy as you would have to spend lots of $$$$s to get better sound . As for the sound, very liquid, nuetral, and of course solid. I don"t think you"d regret the puchase.
Hello All. Is the KSA-250 fully balanced from input through output?

Many Thanks!
I have been using a Krell FPB 300cx in my Main System since early 2003 and have never found a reason to "upgrade," if that is even the proper word. The amp has never even had a hiccup, much less given me a problem; sounds excellent on all types of music; and is very powerful, provides deep, taut bass, is full-bodied and sweet musically; Plays well with diverse pre's and cables. The speaker terminals are the best in the biz -- big wing nuts easy to use and providing tight connections.

Does run a bit on warm side so you need to give it room on top. Only other downsides are that it,(i) provides only balanced inputs, so I have has to use adapters because my Wyetech Opal pre has only RCA outputs (Cardas and BAT make excellent ones) and (ii)has a captive PC so you cannot experiment, of course with no assurance you would do any better. I run it through an Audience AR6 conditioner and it sounds grand.

As they say in the infomercial: Set it and forget it!

Hi guys
I have a KSA freshly recapped a year ago and was using it mostly on the lows but find I could use more power.
I am looking for a FPB 600(non c)and sell/trade 250

can a KSA 250 be put into monoblocks(at what cost)-there is some for sale now but they have never been serviced and at $2300 plus service/change to mono,I dont know if it is worth it.Love the Krell bass though.