Changed amplifiers and need some feedback...

First the details. My current 3 year old system is system is entry level as I am in the audiophile world.
Speakers: I built the Jim Holtz Mini-Statements
Pre-amplifier: Transcendent Sound; Grounded Grid, Mullard 12AU7 tubes
Amp: NAD 326BEE (using pre inputs)
Music source mostly Spotify through Sonos Connect
DAC: Rega Dac R (a recent addition with nice improvement)
CD Player: Onkyo C-7030
Listening room is 16'x16', 9' ceiling with more open space to the rear.

So I decided it's time to upgrade my NAD integrated and look for a pure amplifier.  Purchased a used Odyssey Khartago Extreme stereo amp.  I am the 4th owner as far as I can tell.  Talked with Klaus before I bought and he verified its upgrades via the serial number.  The Khartago arrives and I remove the NAD form the system.  My sample music was Melody Gardot, Sarah Jaroz, Dire Straits, Patricia Barber and the Cars.  My first impression of the Khartago was "what's wrong!"  Something didn't sound right.  It sounded really really airy.  Bass was subdued.  Details were there but it all sounded so different.  Checked polarity of all connections.  All good.

With my original system, vocals were smack dab in the middle of the speakers, as if the singer was standing there.  Instruments were spread between the speakers and I could point to each instrument.  Now, I understand I've listened to the current system for 3 years, of course it's going to sound different.  But the Khartago seems to sound like it has an enhanced spatial effect turned on.  The bass sounds like it's almost in my ears, the vocals are not square in the middle, they're floating in a wide space.  When listening to Drive, by the Cars the bass was very present and powerful with the NAD.  It got lost with the Khartago, it was quiet and seemed to be coming from all directions.  At times I looked at my rear surround speaker as if sound was coming from them!  Just really strange.  If I had to chose this moment I'd stay with my NAD.

So, I'm hoping someone can shed some light on what's happening.  Perhaps there's a problem with the Khartago.  Maybe that's why I'm the 4th owner in 3 years or so.  I did talk to Klaus briefly and he felt it was presenting the music as it was intended.  Maybe?   Is the Khartago a very airy amp by design?

Any thoughts would be appreciated!

I'm not familiar with that and, but that doesn't sound right, wouldn't impress me at all, and would stand in sharp contrast to my F5 as much as it does your NAD. 
Sounds like a phase issue. How are your rear speakers wired into a 2 channel system? 
I suggest starting with the front speakers only to get the stereo imaging correct. If it sounds off, try reversing the L and R leads on one speaker only.
@lowrider57   +1  definitely sounds like something is wired out of phase
To be honest, I had a Stratos, a Tempest and a Candela. They were terrible audio components. I had spurious noise, hum and other low level noise. Klaus was very, very slow in communication. It took over a year and he bought the gear back from me at a much reduced cost. His attitude was very arrogant, he stated my problems were my ac?? not his gear?? I lost bigtime! I gotta be truthful, this was a bad audio year for me when I got into Odyssey Audio. They do have many happy customers though..... In fact, there is someone on right now who is having the same noise issues with his preamp that I had with mine.

Lowrider57, my music only system is just a two channel stereo.  I have a HT system in the same room and made the reference to the rear surrounds, but only to help describe what I was hearing.  But, I too thought I should try reversing polarity on a speaker.  I'll give it a try.  Thanks.
I actually thought this was a send-up and what you were experiencing was a new level of transparency, depth, imaging, detail and air, ordinarily lost in the dull NAD sound. Are you sure this isn’t the case?

I agree with lowrider; there has to be reversed polarity somewhere. That's what it sounds like.
Online polarity test.

(FWIW I've never been truly happy with any component upgrade til I've fiddled with speaker placement again).

Beats me, all I know was I had an Odyssey amp and replaced with a Van Alstine Synergy 450 which was a huge step up .Frank answers the phone as well .
If I reverse the polarity of either the left or right channel, the sound is beautiful!  The bass is back, the voices and instruments are where they belong!  I'll look under the hood later and look for a couple wires that are reversed.  No wonder this amp is on it's 4th owner!  
Thanks for the feedback everyone.

@noromance , I truly wanted that to be the case... and now it can be ;-)
No wonder this amp is on it's 4th owner!  

I hate when somebody has a problem with a component and the solution is to pass it off to an unsuspecting buyer.
Anyway, good luck with the amp. I've heard good things about Odyssey.

Is your preamp phase inverting or phase correct? Start with the preamp and trace the polarity through the rest of the system.
Well done @lowrider57 
Thanks nononsense. But the issue  may be caused by the preamp.

That's a good catch.

Lol! That definitely explains the 3 prior owners. I think this sort of thing -- gear sounding bad because of a significant wiring/circuit mistake, etc -- happens far more often than we’d like to admit. I once had a headphone amp serviced, and the guy said the new caps would "take a while to break in". But even so, it sounded so anemic in bass (as in NO bass), I had to crack it open for a look. Instead or wiring a tiny 0.47uF bypass cap in parallel to the big output cap, I saw that he wired it in series! I did the capacitor ESR calculation, and determined the bass was rolling of (-6dB an octave) starting at 1kHz! It would have been down by more than 20 dB at 100 Hz. A million years of burn-in couldn’t fix that! I also notice L/R channels occasionally being mis-wired in gear, etc.

Glad you got it sorted. Your excellent description of the issue is what lead to the solution!

ALWAYS questions things. Don't assume it was built correctly; people make mistakes (some more than others).
I'll be honest. My first impulse reading the post title was to reply "wwwrrrrrreeeeeeeEEEEEEEEEEEEEE". 
That's my best try at feedback. 
Inspected the inside of the amp tonight.  The left channel speaker terminal had the polarity reversed.  A simple 5 minute job with the soldering iron and it’s back in phase😊.  Simple mistake, simple fix.  I’m going to replace the blue power led too.  It barely illuminates.  Thanks again to all for the assistance!

@kalali, my preamp is phase correct.  That was good to know, even though I’d never guess a preamp would be nothing but phase correct. 

@mulveling I agree, ask questions.  I’m surprised the original owner didn’t send it back under warranty.  Yes, these little errors can easily happen amongst thousands of units custom built.
I've even had test equipment that had wiring mistakes. And not low cost junk either!
Companies like VAC and ARC say they listen critically to every unit before it ships. That makes a lot of sense in light of all the little things that can go wrong during manufacture. High end companies like these have a lofty reputation to uphold! If that reputation gets cracked, even a little, they don't survive. Think of all the damage that may have been done to Odyssey from the prior owners' dissatisfaction on just this one unit. Makes more sense to have a trained-ears listening session for final QA.
Jeff- Glad you figured out the problem, that is great!

mulveling- I agree with you 100% and I don’t think Mr. Bunge was interested in my satisfaction for some reason??? And just so you know it was not “one unit” I lost money on, it was three.

Definitely, Odyssey did you wrong! Their loss of reputation from these incidents is well deserved. I.e. if they make a mistake, it becomes more your problem than theirs. Incidentally, I read the "Mr. Bunge" in your post as "Mr. BungLe" -- a fitting misread here, it seems, lol.

"...even though I’d never guess a preamp would be nothing but phase correct."

A good number of linestage tube preamps have reversed phase. Conrad Johnson is probably the most popular in this group.

Glad you solved your issue. Handmade gear can sometimes require some tweaking. Not a big deal in my book.

First thing I thought when I read the OP post, I thought Phase Issue.

Can't believe Klaus would think that's how the music is intended to sound. 

Suuuure.... let's have the vocalist be an airy mess all over the sound stage.  

The Odyssey amps are very good for the price and can sound 3 D in the proper setup. There are a lot of excellent reviews on these on the internet and they are not often seen for sale anymore. Can they be bettered? Of course but you are going to have to dig deeper in your pockets. The NAD gear also sounds good and may be prefered by some.
If preamp had reverse phase the OP likely would not have had an issue, only when a single channel was out of phase with the other.
That's true, mesch. Phase inverted preamp would not present a noticeable change in the soundstage. 

I believe that single gain stage preamps usually have inverted phase. A second stage will convert the phase back to normal.
Keep in mind, Klaus's preamps are not as good as his power amps. Preamps are very hard to get right and I would look elsewhere from a manufacturer who can get it right like Audio research, Conrad Johnson, and several others with a good track record.