Luxman vs. Accuphase

I am considering purchasing a Luxman or Accuphase Solid State Integrated amp. Does anyone have experiences with both solid state integrateds? Basic differences sonically? Thanks!

i compared at my local dealer the Luxman 590AII, top of the range Class A, with the lower range Accuphase E250, not class A.

No contest, the Accuphase won hands down. The Luxman sounded sterile, dead. All the emotion of the music was in the Accuphase.

Was very disappointed because Luxman looked great on paper.
From what i know both brands have their own advantages. Demoed the Luxman l-509u and i liked it. Nice instrument separation and dynamics.
I am very surprised by your experience. Both the Luxman and accuphase all well known for delivering the goods when it come to musicality and emotion in music. I am sure there will be many Luxman owners who will come to its defense.

Maybe the setup was not in favor of the Luxman for some reason? Thoughts? Associated equipment.
I get fine results with my Luxman 507U. Kind of a Goldilocks sound, not too boomy or bright or etched, lots of character, sweet palpable rounded vocals, nice all-there highs that are not painful. Almost on the level of the Pass X350 power amp I once owned, and bass is better defined on the Luxman. The Pass had a bit more roundness to vocals and depth. Using a good tube preamp with the Luxman as a power amp really makes things shine.
I ended up buying the Accuphase E-450 (now driving Magico V3's), and couldn't be happier with it. As I was winding my way through the decision process, I heard Luxman's 590, but not in a good setup. One of my reasons for deciding for the Accuphase was simply the dealer response and availability for audition (2 years ago, SF Bay Area). I have since listened to Luxman's 505 on SF monitors, and was also very impressed. I think both have potential, but I can personally only recommend the Accuphase, extremely detailed and balanced, without ever sounding harsh. I am less fond of the substantial heat generated by any of the class A versions, but of the AB designs, the Accuphase is outstanding. I know that I wouldn't ever need all the power the E450 can deliver, so could easily see that the smaller models might well be up for the task as well.
Thank you everyone for your responses. I read some similar threads and Accuphase seems to be the most favored although Luxman should be shown no disrespect. I got a quote on a new Accuphase e-360 for 10 grand. Whew, I certainly can't afford a new one so I'll be searching for something used.
Wow, that's over double the price of a new E-360 in Japan. Thanks!
Routeman21, please note that while Luxman has its strengths, it cannot compare with Accuphase in its versatility. I use both digital (PC) and analogue front ends, and my e-450 has made life simple as it use teh plug in DAC board (DAC 30) and the phono board (AD 20), which are both top class. If I want, I can use 2 phono boards, as the two slots are usable for either of the option boards. Accuphase is also a bit more rugged, though there is very little between the two.
I have had the Luxman L-550ax in my system for 3 months now. This is Lux's new iteration of the L-550aII. I replaced a big system, with full blown preamp (EAR 868) and CJ Premier 140 (big tube amp) and haven't looked back. The Luxman offers a very nice sounding selectable MM/MC phono stage (I've got a low output MC cartridge, this was important feature for me), had lots of bells and whistles and knobs and meters, but most importantly for me, has 20 watts of BIG class A (t does run warm/hot) power. In my room, with the Gallo 3.5's, I can't turn the volume past 12 or 1 o'clock. The soundstage, width is maybe a bit narrower than with my old system, the depth is comparable, and the overall quality of the sound is totally dependent upon the recording as it should be. I didn't compare with Accuphase which I'm sure is killer as well. I personally use an Audio Note 3.1 external DAC with my mac mini / JK MK3 digital front end. I'd be surprised if the Accuphase "more rugged" but who knows.
The new Accuphase E-360 integrated is rated at 100 wpc into 8 ohms and only 140 wpc into 4 ohms. I expected 200 wpc into 4 ohms. Am I missing something? Is the E-360 fully balanced? I see that it has two balanced inputs. The unit looked very interesting until I saw the price. Can someone confirm its $10,000 price? As noted above, this is also too expensive for me.

I believe the Luxman L-550xa class A is $5,400 and the Luxman 590AII Class A is about $10,000 (?). Routeman21 above did not specify a price range but it looks like the Accuphase products are more expensive than Luxman. Any comments on the Luxman A/B integrated amplifiers?

I have not auditioned the Accuphase but the posts above imply it sounds better than the Luxman. Any comments on this?

Does Accuphase make a good sounding fully balanced less expensive integrated amplifier?

When buying my E-550 integrated, I have compared quite a few Accuphase integrated, i.e. E-350, E-450, E-550 and E-408 (the predecessor of E-450), and my preference was E-550 > E-408 >= E-450 = E-350 (by ">" I meaning marginally better). Because of the large price difference between the E-550 and E-408 (8500 vs. 4000 euros) I wanted to buy the older E-408 model. In the end I bough the E-550 as the dealer offered me a very good price for it (the E-550 was about to be replaced by the E-560).

I have also listen the E-460 and E-560 models (the E-560 I have compared directly with a E-550) and IMO my initial assessment is still valid, i.e. the sound difference between previous and current generation models does not justify the huge price difference. Consequently, my advice is to look for dealers that still have models from the previous generation, e.g. E-350, E-450 and E-550. You should be able to get these for 30-40% less money (probably a bit more on the 2nd hand market).


Only the top of the line Accuphase integrated, i.e. E-530, E-550 and E-560, which all run in class A mode, double up their current output as the resistance halfs, i.e. 30 watts into 8 ohm, 60 into 4, and 120 into 2. All these three integrated are more powerful than the specs suggest e.g. my E-550 made speakers like Wilson Sophia and B&W 802D cry like babies). However, if one listens to large orchestras or big bands at loud levels than the models from the E-4XX series are more suited, viz. they are much more powerful even though they do not double up their current output as the resistance halfs.

Regarding fully balanced designs, the preamplifier and power amplfier stages of all Accuphase models I have mentioned so far have a balance design (what Accuphase called MCS or MCS+ circuits). However, it seems that only models built like "instrumentation amplifiers" (again Accuphase jargon) can be called fully balanced designs. However, this is can be deceiving. For example, the E-550 model which is not an instrumentation amplifier design is superior to models like E-250, E-350 and E-450 which are designed as instrumentation amplifiers.

Best wishes,
I don't like both sounds, but after listening many times both with different speakers I could choice the Accuphase without any doubt.
Side step a little:

Is Luxman available for purchase in the United States? I owned an R-106 and a R-115 receiver and they were absolutely the best sounding electronics I have ever owned for 2 channel music listening; much better than separates I have auditioned.
Yes, Luxman products are for sale in the US. The distributor for Luxman is On Higher Note

Their Mailing Address:

On a Higher Note, LLC
P.O. Box 698
San Juan Capistrano, CA 92693

phone 1-949-488-3004
Routeman21: Have you made a decision on purchasing a Luxman or Accuphase integrated amp? Are you looking at Class A or Class A/B integrated amps? What models are you considering?

I contacted my local Accuphase retailer and he ONLY carries Accuphase Class A amps and does not carry the E360 or the E-250 (these are still expensive for me). The Accuphase Class A amps are $15,000+ and that is over my budget. The local Luxman retailer suggested I come in for a demo of the Luxman L-550ax using my Sonus Faber Auditor M speakers and I plan to this Friday. I am not convinced I want to sell my Ayre AX-7e amp but it should be interesting to listen to the Luxman unit. Since I need two balanced inputs, I will need to consider the Luxman L-590ax (or L-590a II) since it has two balanced inputs. They had a pre-owned Luxman L-590a II but it sold before I could get there. If I made a change, most likely, I would buy a pre-owned model at a lower price.

I am on the fence and cannot decide if the Luxman Class A amps would be a huge improvement over my Ayre amp. I want to audition an Accuphase so I need to look for another Accuphase retailer. Hopefully, the Luxman demo on Friday will help me decide.
Hgeifman: I decided on a Modwright KWI-200 integrated amp for $5000.00 brand new. I paired it with an Ayre C-5XEmp which is used with low mileage. The Modwright has a little over 100 hours on it so my true evaluation remains to be heard. So far I'm very impressed. I've never heard a Luxman or Accuphase A or A/B amp so I cannot compare to the Modwright.
I have the top of the range integrated Luxman 509u, class AB, 120W (but they seem much more) and I'm very happy, I think it will be my last amp.

Luxman class AB integrated are more neutral, dynamic, with great driving capabilities, they have a great control of the woofers and a very deep bass.

Maybe Accuphase class AB int.amps are more "musical", but they cannot give what I wrote above.

My 509u can easily drive the B&W 803/802D, I don't think Accuphase integrated can do the same.

I heard the new class A Luxman 590AX (it replaces the 590AII), 30W but still able to drive the 802D (Luxman demoed both 590AX and 509u with that speakers @ Tokyo International Audio Show), it gives less dynamics and control, but a lot more warmth than the 509u.

The 590AX (read the Audiodrom review) can be compared with the more expensive Accuphase E560.

All Luxman integrated have a good phono section (MM/MC) the Accuphase don't have.

Since you will take your speakers to the dealer why not taking also your electronics there and do a direct comparison. Your Ayre integrated is very good, and I do not see a reason to hurry things up. Take your time listen to as many integrated amps as possible and wait for the best bargain. (A few years ago, when I bought my Accuphase combo, I have actually compared the E-550 vs. the entry level Ayre integrated. The comparison might not have been fair for the Ayre, i.e. top-of-the-line Accuphase vs. entry-level Ayre, but nonetheless... With my speakers, i.e. Micro Utopia Be, the Accuphase was better than the Ayer, but the Ayre sounded very very good too. I could have live with it.)

Regarding prices, as Nagoya pointed out earlier in this thread, Accuphase prices are crazy outsize Asia. However, you should be able to get a healthy discount from the retail price, I'm thinking 20-25%. (I am saying this because in the Netherlands quite a few Accuphase dealers offer very good discounts, e.g. 30% off, around Christmas and Ester). Maybe that is also the case with the Luxman components which seems to be more earthly priced and consequently seem to be a better bang for the buck.


Some of your comments above are simply incorrect. At least that is my experience. Any Accuphase integrated can drive without problems the B&W 803 speakers (not that anybody here asked this). Also, the E-408/450/460 models will make the 802D B&W speakers cry like babies. So did my E-550 integrated (30 class A watts into 8 ohms), which was in full control of the woofers, but just as you have mentioned not the best choice for dynamic music, e.g. big bands or orchestra music with large dynamic variations. Of course, you are right that the Accuphase do not come out of the box with a phono section. You have to buy one of the available option boards which again cost a ton.

Paul: As recommended above, I listened to the Luxman L-550ax integrated using my Sonus Faber Auditor M speakers and my Ayre CX-7eMP CD player. My immediate response was that the Luxman amp sounded much better than my Ayre AX-7e Integrated amp. I was very surprised and shocked since I was not expecting to hear this much difference. I heard more detail, the voices were clearer and it sounded great. We played voices, classical and jazz from six CD's. After listening for a while, we switched out the Luxman for my Ayre AX-7e integrated amp. Wow, what a difference. I immediately noticed that with the Ayre the music was not as clear, not as open and it sounded dull. We then switched back to the Luxman. We again listened to the same CD's and the same tracks to ensure I was hearing the same musical source. It is hard for me to describe sound but the music sounded much better with the Luxman then my Ayre. Everyone hears different things but I heard a clarity, musical detail and openness that I did not hear with my Ayre amp.

My retailer did not have a Luxman L-590ax amp in stock so we talked about it instead of the L-550ax. Of course, he said it would be much better than the L-550ax but it costs $10,500 and that is too expensive for me. I am sure the L-590ax would be another level of sound improvement but it is out of my price range.

I guess the question is what am I going to do. I was very impressed with the Luxman L-550ax integrated amp. I was concerned about its 20 wpc rating but the retailer said to forget the wattage rating. During listening, I increased the sound volume and we never entered the red zone on the amp. It was loud (very) and still sounded very good. I am going to think about it for while and then make a decision. My gut reaction suggests I am going to buy the Luxman L-550ax amp.
Hi Hgeifman,

I am glad to hear (though a bit surprised) that the Luxman was that much
better than your Ayre (maybe I have listen to a different Ayre integrated).

In the Netherlands the L-550AX is 5800 euros while the L-590AX is 9350
euros. They certainly ain't cheap, the prices being comparable with Accuphase
prices. Unfortunately, that is about the only thing I can say about these two
amps as I have never listened at length any Luxman. When I bought my
Accuphase combo the dealer told me not to bother with Luxman. I have no
idea why he said that as he carries both brands. Probably, he makes more
money when selling Accuphase units. :)

It is hard to say whether or not it is worth while make an effort and buying the
L-590 AX. If, usually, you keep your electronics for 4-5 years or more it is
definitively worth it. Otherwise, probably not. Try to compare the two.

Regarding the wattage, I can tell you that the 30 class A watts (into 8 ohms) of
my Accuphase can go a very long way. However, if you listen to large
orchestras or big bands, i.e. music with large dynamic variation, than 20-30
class A watts will most often not be enough unless you use horns. In the
dealer's room, the power indicators of my E-550 went into the red zone a few
times for a fraction of a second, but this never happens at home.

As mentioned before, don't hurry and do not pay full retail price for the
Luxman. If you bought the Ayre form the dealer that sells the Luxman, he
should offer you 20% discount for the L-550AX and even more, say, 25% for
the L-590Ax. It might also be a good idea to listen the Accuphase E-560
and/or E-550. Here in Europe the E-550 goes for 4000-4500 euros, i.e. less
than a new L-550 AX. Both Accuphase units have a remote control (I read
somewhere that Luxman class A integrated do not have one) and can drive
loads up to 1 ohm (the Luxmans might too do that, though the Luxman site
mentioned power figures only for 4 and 8 ohm load).

Keep us posted!

Best wishes,

Before you make a decision you might want to audition the Luxman L-509U or Luxman L-507U with your speakers.
The Luxman units sells lot more in Japan than Accupahse.
I use to own a Luxman L-507U. I have audition Luxman L-509U Also Accuphase E-450 and McIntosh MA7000. I prefer Luxman and McIntosh.
Hgeifman, if you found the Luxman 550 to be a great match with your speakers and CDP, no need to second guess yourself. Unless one has hard to drive speakers, 20 watts is more than enough. Furthermore, the Luxman integrated amps are excellent amps.

Here are some thoughts from a review of the 590ax from audiorom:

The market price of the L-590AX extends to €8,500. I do not think it is too much as a future owner will get a state of the art integrated amplifier with no reason to change it in next few years. He or she will have no choice anyway as there are no serious contenders. Adding extra €2,000 will buy you the Accuphase E-560, however, apart from its slightly deeper bottom end, you will not get much more. I should also add that the L-590AX includes a very good MM/MC phono preamplifier so one can save substantial money having such a all-in-one solution. If you still want to boost your listening experience you would have to invest into separate Class-A components (a preamplifier and a power amp) – indeed, it is a way, but not in this price segment.
Any comparisons between accuphase and lfd?
I changed my mind. After I ordered the Luxman L-550ax, I kept thinking about the Luxman L-590ax. I reviewed various comments on the Internet and kept thinking about the L-590ax. It makes no sense to buy the L-550ax and want to buy the L-590ax.

After thinking about it for several days, I cancelled my order for the Luxman L-550ax and ordered the Luxman L-590ax. This should be my last amp for a while.

I am hoping to get delivery sometime next week. I will keep you posted.
I picked up my Luxman L-590ax integrated amplifier yesterday from Music Lovers Audio (Retailer). This amp is very heavy and the box is huge (doubled boxed). My neighbor helped me move it from my car to my shelf. The hook up was easy and Music Lovers Audio helped me with some setup questions that they easily answered on the phone.

As I expected, the first several hours, it sounded like it needed more burn in time. It is sounding much better now and I am sure it still needs more burn in time. And, yes, it does get warm to touch.

It is hard for me to describe how it sounds. It seems the music is fuller, with more detail and with better bass control. It seems I am hearing more things than I did with the Ayre AX-7e amp The mid range is outstanding. Okay, I know it still needs more burn in time. I do not understand but it seems classical music sounds better on the Luxman than the Ayre. The music is clearer, more airy and easier to listen to. Overall, the new amplifier sounds very good in my system (more break in time is required). I plan on doing more listening today.

My source is the Ayre CX-7e MP CD player running balanced (Harmonic Technology Magic Link Two interconnect XLR cable) into the Luxman amp connected (Synergistic Research TESLA Quad Speaker Cable) to the Sonus Faber Audio M Speakers on Sonus Faber stands.
The original question was for information on Luxman vs. Accuphase. I received the information below from the US Luxman distributor, On Higher Note, about the company, Luxman.

"Luxman is located in Yokohama, Japan - where they design all the products. They have four factories where they assemble the gear. All of the resistors in the audio chain are custom made especially for Luxman to their exact specifications. Sales & Engineering is approximately 40 employees. In the L-590ax amplifier, all of the parts are Japan sourced. Luxman is owned by IAG out of Taiwan, but they pretty much leave Luxman to sort everything out themselves. They do not tell Luxman what to make, nor how to make it. The domestic market is still 90% of Luxman's business".
Hi Hgeifman,

Congratulation for the new amp!

IMO it was definitively a good move to order the L-590ax especially since you plan to keep it for a long while.

Best wishes,
I own Luxman 590 AX since august 2011. It is a terrific amp., it is worth every penny I paid for it, but I have to say that
burning in process was, in my case, very painful. It took
almost 1000 hours before it opened entirely.
Also I got spectacular additional improvement when I replaced 8 original Luxman fuses with Hifi Tuning Supreme ones.
I hope it is my last amp in life.
I'm curious as well. Thanks to those that have done the shoot outs. If anyone has done any recently, please let us know...thanks.
I'm getting ready to audition Luxman with no comparison to Accuphase but instead Ayre. Hopefully Ayre releases the AX5 this fall.
Luxman is much better than accuphase in term of sound quality and real price-value-for-money!
I've heard several accuphase setups and none of them impressed me at all. I owned luxman l550a2, a terrific class a amp. And now i own luxman pre c7i signature and pow 7i signature. Another terrific products from luxman. You'll never get disappointed w/ lux; but i really get disappointed w/accuphase.
Thanks for the info Iluxman. Cant wait to audition the Lux. Hopefully in a week or two. My wife said if I hang the new bathroom mirror I can get one (I feel like a little kid when I say that. My mom says I can have a twinkie if I clean my room).
It's been a year.... Anyone have any new thoughts to ad to this debate???

I am thinking of replacing my Ayon Triton II, tube int, with the luxman L-590ax or the Accuphase E-560 (?)...
I have a Luxman 590ax in house for a demo right now. It goes back tomorrow... I like what it does, so naturally I am very curious about what one might gain or loose with Accuphase.

What are the real world differences between these two brands (in this case specificly the 590ax vs. the E-560 but all comparisons welcome and useful)?
I dont know if I will be able to demo the Accuphase E-560. I have done plenty of reading about the two but no real world explanations of the differences.

Can anyone put it into audio terms... i.e. Acc has better bass, Lux has smoother highs. soundstage for X is..... etc... ???

Hopefully someone that has spoken on this comparison before can take the time to break it down a little.

Much needed
I have a Luxman 590ax in house for a demo right now. It goes back tomorrow... I like what it does, so naturally I am very curious about what one might gain or loose with Accuphase.
...chasing your tail. If you "like what the Luxman does" in your system then go for it.

I have not heard the Accuphase, so I am just trying to gather a little more information, if possible.
If an answer intrigues me enough to pursue a demo, I will. There might be an aspect or two that my system could benefit further with the Acc... There is a small thing or two I am hoping to hear. We'll see...
But there are two camps here splitting hairs and very few that have actually heard both anyway. So maybe there is nothing more that can be said.
Here is the problem jriggy, you are asking for opinions from people online, which is fine in of itself, that is part of the purpose of these forums, but you have heard the Luxman in your system and state you like it. Is it possible you may like the Accuphase better, sure, but it is a gamble based on some comments. On the other hand you have a sure thing. Another sure thing, there is always something better.
Hi Jriggy,

A few years back a dealer in The Netherlands ( AudioLife ) has organised an Accuphase vs. Luxmann show. Unfortunately, I could not go. You might want to call them. They are very friendly and if you explain them the situation they might be willing to share with you a thing or two (English is not a problem for them).

Also, have you seen the review below?

Luxmann L-590ax

I am an Accuphase guy, however, the few times I have listen Luxman electronics I have liked them very much. IMO both companies make very very good products and neither can be considered as being totally superior. Accuphase is more expensive and IMO has a more classier look and it is a bit more flexible (e.g. you can add a DAC to it and it also has a numeric indicator for the volume control). The Luxman looks a bit funny IMO, it has eyes, ears and teeth. :) However, overall, the Luxman probably offers a better bang for the buck as it is significantly cheaper.

Buying the Accuphase without being able to try it in your system might be a mistake as you might end up paying more for something that will give you less. At this level system synergy and personal preference are very important.

Also, be aware that Accuphase has introduce the E-600 class A integrated, i.e. the evolution of E-560 (which will be discontinued). Thus, you should be able to get a significant discount for the E-560.

Finally, be warn that these Japanese boxes are very addictive. Once you have one in your system you will want more! :)

Keep us posted.
Hi Paul, when will the E-600 be released? At CES? Also, have you heard anything about the A-65 being replaced by a new model?
I got a statement from an audiophile friend in AU... Says the Luxman has a warmer tone and the Accuphase is purer and sweeter.

Could it be agreed with that the Lux is warmer sounding than the Acc?

He also says the Acc is better to his ear but of course that is subjective --and stated as so. But the other part of the statement seems to be a real world/tangible/observable difference that should be able to be corroborated.
One Japanese Audio Award, maybe biased, interesting to see nonetheless.
Dave, I have answered your question in a PM.

Bvdiman, it is funny to see how some products receive awards the moment they are released...

Jriggy, the few times I have listen to Luxman electronics they give me the impression they do not sound as full as Accuphase. Some may like that while other may not. Also, it could have been the speakers and/or room that gave me that impression - I have never compared the two in the same room with the same speakers.
Hi Paul,

I have replied to your PM. Thanks.

I own the Luxman 590ax integrated amp and like it very much. I was not able to compare it to Accuphase since my local dealer had no demo models for me to hear.

I really like the warmth of the class A Luxman using my Sonus Faber Monitor M speakers. The Luxman drives the speakers with no problems in my large listening area. Of course, you have to listen to both models but I encourage you to listen to the Luxman Class A models (550ax and 590ax).
Hi Hgeifman,
what is the burn in time? I own Luxman L505ux, it is 4 months old.
and what IC and PC is being used.
Murgeshj: My Luxman 590ax sounded good when I first started playing it. However, it really sounded great after about a month of daily playing time.

I am using the Apple MAC Book Pro Computer, a LaCie external hard drive, the Ayre QB-9 DSD DAC and the Sonus Faber Olympica II Speakers. This Luxman Class A amplifier drives the SF Olympic II speakers to loud levels in my living room. The Luxman L-590ax is fully balanced and I am using Harmonic Technology Magic Link Two Interconnect Cable balanced cables from the Ayre QB-9 DSD DAC to the Luxman. My local retailer has suggested I replace my Harmonic Technology IC with another cable so I am thinking about it.

The Luxman amplifier is very heavy and the box is huge (doubled boxed). And, yes, it does get warm to touch but the heat is not a problem. It does need plenty of open air around it.

It is hard for me to describe how it sounds. For me, the music is fuller, with more detail and better bass control. It seems I am hearing more things than I did with my Ayre AX-7e amplifier. The mid range is outstanding. I do not understand but it seems classical music sounds much better on the Luxman than the Ayre. The music is clearer, more airy and easier to listen to. Overall, the new amplifier sounds excellent in my system. I listen to classical, jazz, blues, country and new age.

I have owned the Luxman since May 2012 and I like it very much. I have stopped looking at other integrated amplifiers since the Luxman 590ax sounds excellent. As you know, the Luxman is a class A amplifier and I really like class A sound. In summary, I highly recommend the Luxman 590ax amp.

I encourage you to listen to the amplifier and see what you think. If possible, you should try it in your own system.

Do you have any more questions?
I previously owned an Ayre AX7E and replaced it with a Luxman 505ux and I'm very happy. The Luxman simply sounds better to my ears. It does have decent phono input but not nearly as good as the Graham Slee Reflex C that I'm using. I also like the loudness option for low-level listening (my home office is also my music room!). I'm using the Luxman with Harbeth SHL5 speakers and it's a great match.
So Before I purchased my Luxman L550AX from Music Direct, I had a chance to keep both 550AX and 590AX and compare them side by side for two weeks.
The source was Ayre CX7eMP cd player connected via Balanced Cardas Clear Reflection to both amps. 
Speakers - Reference 3A Veena connected to amps via bi-wired Cardas Clear Reflection speaker cable.
Room - acoustically treated 11 X 13' 
Both amps got 120 hours initial burn in time and both were used with Cardas Clear power cable.

In my room, with my music taste, matching equipment  - I was NOT able to hear ANY diffrence bewteen 550 and 590. The later is FULLY balanced design while 550 uses buffer after balanced input making it single ended.

I purchased the cheaper option - L550AX and will not look back!! Make sure you always listen to the equipment that you want to buy at home!

I have owned Luxman 590 integrated, M800a as monos, ARC Ref 250, Ayre MXR, Accuphase A70.  Both the Luxman to Accuphase are fairly supple and rich sounding as far as solid state goes.  In comparison to the Luxman, the Accuphase has better detail and micro-dynamics.   It has as much bass drive and dynamics as the M800a in monos.   Both have very high built quality.  The Ref250 has slightly better micro dynamics and a trace wider tonal palette than the Accuphase.   The Accuphase has more extended highs than both the ARC and the Luxman.  All these amps are very good.   Make sure you pay attention to phase if you use XLR.  Japanese configuration is different.  I also prefer the Accuphase to Xa100.8.    The XA has slightly better bass macrodynamic and channel separation but I prefer the A70 for micro dynamics, detail, wider tonal palate and a more supple top end.  

The Pass feels even more quiet and separation of individual instruments are very distinct.  I almost feel these qualities are artifactual as each individual instruments in an orchestra should not occupy so much space . The portrayal of strings has more  straight edges and violin sounds slightly stringent comparing to the A70 and the Ref250.   The accuphase better conveys how one note evolve to the next and this keeps it interesting for me.