Odyssey Stratos or Krell 400Xi for Usher 6381's

Do you guys think the Stratos amp has enough power for these speakers? If not the standard model, then how about with the cap ugrade?

The other unit I'm looking at is the Krell KAV-400Xi integrated. From what I've read it has good power.

I've sold my amp so I have to get serious about finding a replacment.

Naim CD5i for source. Arcam AVP-700 would be used in by-pass mode for pre-amp if I go with a seperate amp vice an itegrated.

You thoughts please.
For the Stratos, the dual mono (180 wpc) is one way to go; 20% more power than the regular Stratos, if the specs are to be believed. One just sold here for $1250. I have the extreme version, and enjoy it; I'll also join the choir about how great Klaus is to deal with, including supporting gear purchased used. Don't know the Krell, but it looks like a bigger investment for you (one listed for $1850), since you've got the pre covered.

The odyssey extreme stereo, or the Dual Mono would be good... They don't really have more power per watt I believe but they have higher capacitance and the Amperage out goes way up... Current controls the speakers so I would guess this is a good way to get super high current. I think they hit something like 120 amps per channel, so if you go look at most of your amps out there they are normally only somewhere between 20 amps to maybe 50 amps per channel, I know the odysseys lay it down and are not really equaled in this realm, especially for the money.
By the way I noticed in another thread of yours with some concerns about overheating, the Stratos series does not even break room Temp.. Its the coldest lowest noise(no hum) amp I have ever encountered with high power and current like this. you could be stunned when touching it that it never seems to turn on.... Also a lot of the times odyssey recommends leaving them on 24/7 they pull no power and create no heat in my experience.. maybe a couple bucks a month on the power bill but I never noticed it one way or the other with them on playing all the time or not used at all...I had Krell, Classe', Forte, Ps audio, Threshold, Muse, Coda, Bryston and probably a couple more I can't think of that I have had... All ran pretty hot, and a couple RED hot after being on for a couple hours when Driven or sitting at idol.. This just does not happen no matter what I do to the odysseys for 24 hours plus.. very efficient solid amps with better part quality than any for the most part that I owned.
I'll chime in with a third recommendation for the Stratos Dual Mono. I'm actually the one who purchased the one recently sold and have had it in my system for a week now. Sorry, but I can't compare it directly with the Krell. It does take an authorative grip on my 89db monitors and is fast and detailed, slightly on the warm side with my tube preamp. I'd say a tremendous bargain at the price, even new. The only Krell's I've heard had a more squeeky clean SS sound with gobs of detail and drive (this from memory of a bi-amped Krell system that left a lasting impression). I think that particular system used Krell amps that are well beyond the price of a Stratos DM or Mono Extreme. Have not heard the 400Xi, and my memories are from long ago, so take from it what you may. Unlike Undertow's experience I would say the Dual Mono runs on the warmish side when serving up the tunes. Not class-A hot, but unmistakably warm. For what it's worth you can find more user feedback on the Dual Mono version here.

Yeah the Dual mono board adds some heat but nothing significant.. The stratos and the extreme are not the same as the Dual mono's which are 2 Amps in one chassis so that is the reason.. sharing 2 amps on one heatsink vs. one amp on one pair of heatsinks.. I can say the Khartago from odyssey runs warm, its the same amp, but in a smaller chassis with less heatsink..
Thanks everyone for your fantastic inputs.

I have a chance to get a one yar old stereo stratos with red board (what ever this is) and cap upgrade for $800 shipped. However, it has a silver face plate and I need black. This will probably add about another $100 to the price tag, if these are even user replaceable.

I'm thinking that $900 total is stil probably a pretty good deal. I figure I can give the amp a try and see how things turn out. And, with the money I saved buying used I can upgrade it to the hilt later on if needed or as desired. Will give me something to look forward to. :-)

Any of you guys change the color of the cool light on this amp? Curious if this is a bulb change or what. I sent Klaus an email asking if it was possible get the light in different colors (I would like greem to match my Arcam and Naim equipment)and he said it was.

Just curious if any of you had changed yours.
Just want to point out, though you may already know; the Stratos is a power amp that requires a preamp or an input with some kind of variable attenuation (passive or active). I say this because the Krell you were considering is an integrated amp which obviously has the pre stage built in (or at least passive attenuation). Also, it sounds like the Stratos you are considering is the 100wpc stereo version, while the one I and others have recommended are the 180wpc versions. I have no experience with the standard version so have no idea whether it fits your criteria. The Dual Mono version should have no problem pushing challenging loads I suspect. I would get some input on the version you are considering.


Well, depending how good you are with stuff, there is 4 bolts holding the face on.. Yes you could get LED's, but you need to cut the wire add some quick connects and put in new lights, I would not de-solder the wire from the board it is really thick and solid solder very hard to melt in this case.. I have just installed quick connects myself, cause I had to change a pair of LEDs myself due to I have 2 extremes and one was shipped with the old blue ones and the new one has a different blue.. But I got the correct LEDs from klaus and I have no idea where or what you would need to buy if you wanted red or yellow or something, so you will need to talk to them if all can be used, I would assume it is a pretty basic same type power draw LED that any others would be.. If you know a little about quality and how to pay attention to details taking apart the front and can put it back as stock, which for me is easy then the answer is yes you can do it.. Nothing very dangerous you can screw up on the front panel at all.

Good thing is the power switch is mounted on the back of the unit anyway so nothing really intricate to mess with.. However be careful of the glass when you take out the screws for the LED mount tabs it will come out and can shift around when loose, so you want the light to not shine out past the seal either or it will look funny, so make sure it is re-centered and sealed back to the aluminum well.
Jax2, if I went with the krell I was going to utilize the HT by-pass option. I understand your recommending the dual mono amps. But, the Stratos is not 100 watts, it's 150, plus it had the cap upgrade, so it should be fine. I realize I wont get the maximum performance until I upgrade.

Undertow, thanks so much. I'll just order the face plate and put it on and then when I send the amps to be converted to dual mono I'll let Klaus make it green. :-)