Krell Evolution or Pass XA.5 series

Anyone compare the Krell Evolution to the Pass XA series (all prices being equal) on medium efficiency speakers (89-93db). Curious if you did compare them what was the circumstances and system. I did read in one magazine the XA has a warmer midbass, while the Krell Evolution has better bass. I just want a little more information than that.
... while the Krell Evolution has better bass.
Dgad (System | Threads | Answers)

Would you define "better bass"?
It was a short blurb. I guess stronger bass would be more correct. I am curious about other peoples experiences. As I have only heard them at shows.
Stronger meaning louder bass relative to the midrange and treble? If not louder, then define stronger.

In other words, if a Pass Labs amp produces well-defined, controlled bass in balance with the midrange and treble (which is what I hear from mine), then if the Krell produces bass that's louder than the midrange and treble, you would consider this stronger (and better)?

Just trying to get a handle on what type of bass production you want.

I am just trying to remember what I read. Not sure exactly what they meant. I would love to get some input from others if they have compared the Evolution Series to the Pass XA series. I wouldn't ask if I have. I have heard the Evolution in unfamiliar systems. One time it sounded incredible, a 2nd time very good & a 3rd time poor. Pass XA series I have not heard, but I have heard X series and thought it not special.
Good bass, controlled bass. Micro and macro dynamics. The talk of highten bass towards mid and highs. Nah, forget that. That is simply a user, using speakers that are not suited for the room. The Krell amps drive the bassdrivers in a manner most would only dream of. There are many amp-makers that talk of the evolution of their brand. I have used Krell and many more, back in the days and heard Pass Labs. I would go for Krell. There are many krell-dislikers. Don't care about them. Of all the amps i've heard, older Krell amps simply rules in some specific key areas. The later amps are statement amps. The EVO amps are superb. I would not trade them if i had them.
Just listening to a good, or bad recording will reveal absolute inner detail in the bass area (hear they are true ref amps) . Most other amps will not do that. Also, the Krell amps are completely silent, no hum or background noise at all (no bass bloom either). Pass Labs, with all respect, i would listen myself. If i could not do that, i would go Krell because you will not go wrong with those amps you talk of. What is a thing to learn about the Krell is that they will not make bloom as with Pass. It is simply a manner of how you would like it. If you use speakers that has a tendency to sound cold or harsch you might like bloomy sound. But the later Krells are not cold or harsch at all. The c series and older could be hard in tone, but not from cx and forward. I firmy believe, if you have not used a Krell amp of that magnitude, you are in for a serious experience that is only possitive.
I seriously hope you see to it that you demop a EVO amp, you will be hooked directly.
Well I had the Pass X600.5 side by side to the Krell EVO402 in my system. In my system they sounded much alike. The new EVO line is much more musical than the old series. However the typical Krell bass is also gone with the new EVO line.

The Pass was better in the bass and also in the mids. The Krell sounded a little cleaner but also leaner. In the end the Pass was just better in my system.

But the EVO402 is a very good amp and does sound much better than the older 400CX but at about 1.5 times the price also.

My friend tried the XA series next to the EVO and the XA series have better bass than the new EVO402. Krell went away from what made them famous. In the mids the XA also won. On very demanding speakers the Krell might be a better choise but on average the Pass XA series just sound better.

I would love to see more comments on this post. I am considering an Evolution 302 or 402 (not the "e" version $$). I own a Pass amp and have owned others in the past. I think the Pass amps do best when in Class A mode and suffer when they move out of A and into A/B. So it is my belief that if going with a Pass amp that is not pure class A, one must keep in mind how much power they really need for their primary listening habits and then buy the Pass amp that delivers in Class A to the power range they need. Under this scenario, Pass amps are great. Forcing them into A/B mode for much of ones listening may likely result in a lower level of satisfaction. I am sure there will be Pass fans who disagree with this assessment, but it is based on what I have experienced.
Do you own an XA.5 series amp or one of the older series? I agree with you about Pass Class A. I've owned many but never any of the X series.
Well, Since I had Pass labs x.250.5 and experience with xa series,plus, I have been living with Krell EVO 402 for more than 2 years. I think I have the right to tell a word:
I don't like statements such as A is better than B.
I can't say Krell is better than Pass. Simply because both are different. I can not compare. The important thing is what kind of presentation that you are looking for? What type of speakers you have? 4 ohm or less? or you have tube preamp and you need a descent solid state power in order to recompensate some tube related undesired outcomes, or you think that your cables have a house sound of lean or weak bass, than, answer is Krell for cure. If not Pass will be just fine.
This is a very old thread of mine. Not as relevant as it was. I happen to find the Pass XA series to be excellent but the Krell EVO line very life like in speed and transparency. I never heard the Pass XA on medium efficiency speakers that go down to 3 ohms. But the XA30.5 I heard on some monitors was something of a special seductive sound. The best I heard Krell EVO was on their Modulari speakers. Something special but leaning away from organic towards the transparent/neutral side of things. Maybe a touch cold in comparison. But these are short listening opportunities that came up under unfamiliar conditions. Speakers at the time were Maxx 2s.
Pete, I do not own the XA.5 series. I owned the 150.5 (and prior to that a straight 150 for a short time) and an Aleph 5 (which I bought specifically for my Gemme speakers but also have listened to it with W/Ps). I have heard the XA.5 series and I do think they are excellent amps. I like Pass amps, but I like them best in class A and find that when they go from class A to A/B they do not perform in the same manner as when they are operating in class A. I can highly recommend Pass amps and my suggestion or caveat is that one buys them on the basis of how much power they need and will be better off knowing that that power can be delivered in class A as much as possible (with the Pass amps). Since I am currently in the market for another amp, the Pass XA series has been on my list, but in the end I doubt I will go that route.
Well in my previous post I had the Wilson Maxx as speakers. I now changed the speakers to Wilson Sasha. I changed the amps to Pass XA160.5. But recently I bought the Krell EVO600 mono blocks and they play much more life like on the Sasha. The bass is tight and has slam. Also the mids are very clear and open. Compared to the Pass it is much more dynamic and clear and open.

So in this case I preferred the Krell EVO set. I am now going to sell the Pass.

So what is better depends on your configuration. Pass and Krell are both excellent amps. The Krell is more expensive but can sound better in some systems. In other systems the Pass may sound better. With electrostatic speakers or very analytical speakers with ceramic drivers the Pass might just add some musicality.

So try before you buy. The matching with the speakers is the most important and of course what you want to hear.

Krellfan said: "with ceramic drivers the Pass might just add some musicality."

I think this is in general a good statement. Overall, I too prefer the Krell based on past and present ownership of the two brands. Those 160.5's are great amps and deliver a lot of power in Class A mode. Personally, I like the FPB-C Series best for the Krells. I did have good experience with the 300-C and Thiel, but in the end I prefered the Levinson with the Thiels as the Krell could become a bit strident with them (as referenced above by Krellfan).

The key to getting the best bass is going to come more from the room characteristics than the amp (between these two) in my opinion.

Either the Pass or Krell will beat the other when one is in a well treated room and the other is not. If you don't already have this addressed, you may want to look into this first as no amp can have great bass in a bad sounding room!