My Long List of Amplifiers and My Personal Review of Each!


So I have been in a long journey looking to find the best amplifiers for my martin logan montis. As you know, the match between an amplifier and speakers has to be a good "marriage" and needs to be blend exquisitely. Right now, I think I might have found the best sounding amplifier for martin logan. I have gone through approximately 34-36 amplifiers in the past 12 months. Some of these are:

Bryston ST, SST, SST2 series
NAD M25
PARASOUND HALO
PARASOUND CLASSIC
KRELL TAS
KRELL KAV 500
KRELL CHORUS
ROTEL RMB 1095
CLASSE CT 5300
CLASSE CA 2200
CLASSE CA 5200
MCINTOSH MC 205
CARY AUDIO CINEMA 7
OUTLAW AUDIO 755
LEXICON RX7
PASS LABS XA 30.8
BUTLER AUDIO 5150
ATI SIGNATURE SERIES 6005

With all that said, the amplifiers I mentioned above are the ones that in my opinion are worth mentioning. To make a long story short, there is NO 5 CHANNEL POWER AMP that sounds as good as a 3ch and 2ch amplifier combination. i have done both experiments and the truth is that YOU DO lose details and more channel separation,etc when you select a 5 channel power amplifier of any manufacturer.
My recollection of what each amp sounded like is as follows:

ATI SIGNATURE SERIES 6005 (great power and amazing soundstage. Very low noise floor, BUT this amplifiers NEEDS TO BE cranked up in order to fully enjoy it. If you like listening at low volume levels or somewhat moderate, you are wasting your time here. This amp won’t sound any different than many other brands out there at this volume. The bass is great, good highs although they are a bit bright for my taste)

NAD M25 (very smooth, powerful, but somewhat thin sounding as far as bass goes)
Bryston sst2(detailed, good soundstage, good power, but can be a little forward with certain speakers which could make them ear fatiguing at loud volumes)

Krell (fast sounding, nice bass attack, nice highs, but some detail does get lost with certain speakers)

rotel (good amp for the money, but too bright in my opinion)

cary audio (good sound overall, very musical, but it didn’t have enough oomph)

parasound halo (good detail, great bass, but it still holds back some background detail that i can hear in others)

lexicon (very laid back and smooth. huge power, but if you like more detail or crisper highs, this amp will disappoint you)

McIntosh mc205 (probably the worst multichannel amp given its price point. it was too thin sounding, had detail but lacked bass.

butler audio (good amplifier. very warm and smooth sweet sounding. i think for the money, this is a better amp than the parasound a51)

pass labs (very VERY musical with excellent bass control. You can listen to this for hours and hours without getting ear fatigue. however, it DOES NOT do well in home theater applications if all you have is a 2 channel set up for movies. The midrange gets somewhat "muddy" or very weak sounding that you find yourself trying to turn it up.

classe audio (best amplifier for multi channel applications. i simply COULDNT FIND a better multi channel amplifier PERIOD. IT has amazing smoothness, amazing power and good bass control although i would say krell has much better bass control)

Update: The reviews above were done in January 2015. Below is my newest update as of October 2016:



PS AUDIO BHK 300 MONOBLOCKS: Amazing amps. Tons of detail and really amazing midrange. the bass is amazing too, but the one thing i will say is that those of you with speakers efficiency of 87db and below you will not have all the "loudness" that you may want from time to time. These amps go into protection mode when using a speaker such as the Salon, but only at very loud levels. Maybe 97db and above. If you don’t listen to extreme crazy levels, these amps will please you in every way.
Plinius Odeon 7 channel amp: This is THE BEST multichannel amp i have ever owned. Far , but FAR SUPERIOR to any other multichannel amp i have owned. In my opinion it destroyed all of the multichannel amps i mentioned above and below. The Odeon is an amp that is in a different tier group and it is in a league of its own. Amazing bass, treble and it made my center channel sound more articulate than ever before. The voices where never scrambled with the action scenes. It just separated everything very nicely.
Theta Dreadnaught D: Good detailed amp. Looks very elegant, has a pleasant sound, but i found it a tad too bright for my taste. I thought it was also somewhat "thin" sounding lacking body to the music. could be that it is because it is class d?
Krell Duo 300: Good amp. Nice and detailed with enough power to handle most speakers out there. I found that it does have a very nice "3d" sound through my electrostatics. Nothing to fault here on this amp.
Mark Levinson 532H: Great 2 channel amp. Lots of detail, amazing midrange which is what Mark Levinson is known for. It sounds very holographic and will please those of you looking for more detail and a better midrange. As far as bass, it is there, but it is not going to give you the slam of a pass labs 350.5 or JC1s for example. It is great for those that appreciate classical music, instrumental, etc, but not those of you who love tons of deep bass. It is articulate sounding too
Krell 7200: Plenty of detail and enough power for most people. i found that my rear speakers contained more information after installed this amp. One thing that i hated is that you must use xlr cables with this amp or else you lose most of its sound performance when using RCA’s.
Krell 402e: Great amp. Very powerful and will handle any speaker you wish. Power is incredible and with great detail. That said, i didn’t get all the bass that most reviewers mentioned. I thought it was "ok" in regards to bass. It was there, but it didn’t slam me to my listening chair.
Bryston 4B3: Good amp with a complete sound. I think this amp is more laid back than the SST2 version. I think those of you who found the SST2 version of this amp a little too forward with your speakers will definitely benefit from this amp’s warmth. Bryston has gone towards the "warm" side in my opinion with their new SST3 series. As always, they are built like tanks. I wouldn’t call this amp tube-like, but rather closer to what the classe audio delta 2 series sound like which is on the warm side of things.
Parasound JC1s: Good powerful amps. Amazing low end punch (far superior bass than the 402e). This amp is the amp that i consider complete from top to bottom in regards to sound. Nothing is lacking other than perhaps a nicer chassis. Parasound needs to rework their external appearance when they introduce new amps. This amp would sell much more if it had a revised external appearance because the sound is a great bang for the money. It made my 800 Nautilus scream and slam. Again, amazing low end punch.
Simaudio W7: Good detailed amp. This amp reminds me a lot of the Mark Levinson 532h. Great detail and very articulate. I think this amp will go well with bookshelves that are ported in order to compensate for what it lacks when it comes to the bass. That doesn’t mean it has no bass, but when it is no Parasound JC1 either.
Pass labs 350.5: Wow, where do i begin? maybe my first time around with the xa30.8 wasn’t as special as it was with this monster 350.5. It is just SPECTACULAR sounding with my electrostatics. The bass was THE BEST BASS i have ever heard from ANY amp period. The only amp that comes close would be the jC1s. It made me check my settings to make sure the bass was not boosted and kept making my jaw drop each time i heard it. It totally destroyed the krell 402e in every regard. The krell sounded too "flat" when compared to this amp. This amp had amazing mirange with great detail up top. In my opinion, this amp is the best bang for the money. i loved this amp so much that i ended up buying the amp that follows below.
Pass labs 250.8: What can i say here. This is THE BEST STEREO AMP i have ever heard. This amp destroys all the amps i have listed above today to include the pass labs 350.5. It is a refined 350.5 amp. It has more 3d sound which is something the 350.5 lacked. It has a level of detail that i really have never experienced before and the bass was amazing as well. I really thought it was the most complete power amplifier i have ever heard HANDS DOWN. To me, this is a benchmark of an amplifier. This is the amp that others should be judged by. NOTHING is lacking and right now it is the #1 amplifier that i have ever owned.
My current amps are Mcintosh MC601s: i decided to give these 601s a try and they don’t disappoint. They have great detail, HUGE soundstage, MASSIVE power and great midrange/highs. The bass is great, but it is no pass labs 250.8 or 350.5. As far as looks, these are the best looking amps i have ever owned. No contest there. i gotta be honest with you all, i never bought mcintosh monos before because i wasn’t really "wowed" by the mc452, but it could have been also because at that time i was using a processor as a preamp which i no longer do. Today, i own the Mcintosh C1100 2 chassis tube preamp which sounds unbelievable. All the amps i just described above have been amps that i auditioned with the C1100 as a preamp. The MC601s sound great without a doubt, but i will say that if you are looking for THE BEST sound for the money, these would not be it. However, Mcintosh remains UNMATCHED when it comes to looks and also resale value. Every other amp above depreciates much faster than Mcintosh.

That said, my future purchase (when i can find a steal of a deal) will be the Pass labs 350.8. I am tempted to make a preliminary statement which is that i feel this amp could be THE BEST stereo amp under 30k dollars. Again, i will be able to say more and confirm once i own it. I hope this update can help you all in your buying decisions!


whitecamaross

Showing 50 responses by whitecamaross

So I am saying reviewers get paid to say certain things which makes the review biased. I am not really leaning one way or the other. I bought the dac to try it and see what it does for me and it seems like it may have elevated things just a little bit. I don’t think it’s worth the extra $ from what I had but what I had may not be what others had. In that case then yes the Dave would me a huge upgrade. 

The outlaw is not at the level of a krell amp but if it’s home theater what you’re doing then it’s more than enough. If you’re also doing music then your better off with something else. 
Hi, yes the Arcam is incredible. I actually just bought it because I planned on using it in my future dedicated room and it turns out I didn’t expect it to sound as amazing as it does. I can’t believe how great this thing is. I would say that yes it can be used for both. Is it going to best a Yamaha processor with matching Yamaha amp? That would be an amazing exercise I’d love to take on but I don’t have a home theater set up so I can only give an opinion based on its 2 channel performance. The Arcam 850 really surprised me. I didn’t expect that from a receiver. Far better than anything I heard from anthem recently.
on my way to get the wireworld platinum usb cable.... let's see if this will make the chord deve sound any better or not..
McIntosh 207 doesn't touch the Odeon. Odeon is the best multi channel amp there is. Period 
Ok men and women... the Jeff Rowland’s 925s are unpacked, set up, and powered on using my luxman 900u preamp.
Preliminary update: from a dead cold start, after traveling for over a week, they are THE BEST SOUNDING AMPLIFIER IVE OWNED. I’m shocked how clean, clear, accurate, detailed, smooth, and with a huge amount of detail and detail ive never heard before.... this is incredible.... I’m in shock to say be least. Well done Jeff Rowland. Incredible is an understatement.
Pass labs, simaudio, Bryston, audio research, McIntosh, Hegel, ati, theta digital, Classe audio, krell, luxman, boulder, nad, Cary audio, Plinius, Parasound, bhk ps audio, Mark Levinson, Belcanto: YOU ALL NEED TO PAY JEFF ROWLAND A VISIT AND TAKE A FEW COURSES FROM HIS BOOK. You all have been SMOKED.
You all know by now I’m the harshest critic here but I’ll be the first to say when I’m impressed and these amps have beyond impressed me. 
I should close this thread now...
307am and i am just going to bed... couldn’t get off the couch. I have a lot to share tomorrow when I get up. Outstanding set of amps. I was going to bring a pair of 160.8s with the xs preamp and I honestly don’t think it will beat the luxman/Rowland combo.
Hi guys,
i have not connected the platinum usb, or the wireworld silver 7 speaker cables or even using upgraded power cords and yet it’s intoxicating how good they sound. 
I want to enjoy it as what they are now and then bring cardas clear audio speaker cables since it’s what matches very good with Rowland, then use the platinum 7 usb cable, then the luxman d08u arrives next week and then the Rowland Capri s2 preamp the week after that. 
A lot of more tweaks I have in mind for this. I just want to enjoy it as it is right this second. 
Lastly, I had a bit of bass boominess with the Wilsons and Hegel, simaudio and with the Rowland’s that has now vanished. Sounds as if I ran room correction and fixed the bass. Very incredible. 
The rest of my solid state amps sound like a music video from the 80s sounds on YouTube... the Rowland’s 925s are like listening in 4k and the other amps a good 1080p signal.
I left them playing music while I’m out all day today and will return tonight with cardas clear audio speaker cables.
I’ve yet to use the ref10 but the luxman seems to have tremendous synergy with the Rowland amps. I also don’t really think it’s smart for me to use a tube pre when the amps sound like tubes already. I want to slowly enjoy this time around. I don’t want to rush through my music even though I listened to 5 hours of music last night. I keep digging old music just to see what things I’ve missed before in all of the music I thought I knew. I will say to you that the Rowland’s make you hear your music in a way that you haven’t before which is with more detail, space and oh the instrument separation is just crazy...
they are like the luxman set up on steroids... very similar with tremendous finesse 
Limiscate: the Hegel should be left on... it does not consume a ton of power just left on unlike pass labs amps. It also does not run hot at all. I hope you like it’s muscular presentation. 
The only thing I need to figure out is the setting on the back of the amps for the phase. Not sure what luxman pre is for xlr so that I can match it to the Rowland. 
Yes and the Hegel is far superior via balanced. Don’t mess with rca. 

Ron: why is this a big league for you man? You have outstanding amplification as well. Keep following it this 
Thanks pokey. Appreciate your comments. 
Maybe I should open a store dedicated to selling only power amps ? Haha 
Just connected the cardas clear audio cables and things got warmer with more bottom end. I’ll have them listen more tomorrow. 
W100i: funny that you say that but I tried what you said and I felt the chord Dave sounded damn good as a preamp in my system. I’d be happy using it as a preamp. 
Maybe the cardas cable will open up over time. Right now I felt that the cheaper cable I was using gave the amps more air and detail. I have not tried my silver 7 wireworld yet. 
You need to forget rca through Hegel. I told you this before. Hegel sounds best through balanced inputs. I got hiss which is normal. 

Update: I bought the bluesound vault 2 and connected it via optical to my chord Dave dac. I also have the chord Dave dac connected to my laptop via usb and I’m now using the platinum usb cable. I don’t really hear much of a difference between the bluesound playing tidal and feeding it to the dac or the laptop feeding it to the dac via usb using that expensive usb cable. 
If there’s any difference then I’d have to find a song that shows me that because I’ve tried 30 or more songs and I can’t hear anything difference between using usb with an expensive usb cable or a cheap monster optical cable coming from the bluesound vault 2. Hmm. This is quite shocking. 
I suspect the Rowland amps do about 60% of the magic here. Everything seems to sound very good through them. Eve a crappy source like pandora sounds like I’ve never heard it. Yes im using pandora to break in the equipment when I’m away. 
Limniscate: i got hiss as well, but my ps audio p20 helped to lessen that hissing. That said, the hissing you are referring to is apparent only if i have my ear close to the tweeter. It is not like i can hear it from my listening position so we are somewhat nit picking here.
The transformer hum again is pretty normal because this amp uses big transformers. Both of my hegels had a little hum, but again you have to kneel down and put your ear close to the amp. Transformer hum is not abnormal unless you are hearing it from your listening position.
As far as your veritas being dead quite, yes they are because they are class d and it is a different design. I also do not get any hiss from my former class d amps. Class d in general is quieter than class ab.
At least you are not getting humming though the hegels. I had humming through the speakers at one point, but i found out what it was.

ricred:. The chord dave is great, don’t get me wrong. The truth is that the vast majority of the people who read this would probably be floored by it if they brought it home. What many of you have to remember is that my experience is vast and right now i am playing with ultra high end amps so in my situation the chord dave is good and not OMG ITS THE BEST THING I HAVE HEARD. However, some of you with less expensive sources, speakers, amps, preamps, etc might be floored by what it can do. I actually feel like unpacking the ps audio direct stream and do a shoot out against the chord dave. Lastly, i will be getting the rowland capri s2 preamp next week and will be trying to see if it can beat my luxman 900u preamp. If it does then i am keeping it and the luxman will be sold. Right now, i am on the Jeff Rowland bandwagon.
Oh, and i wanted to add one thing.. i have an arcam avr850 receiver which i unpacked and used with my chord dave dac and man that receiver sounds amazing. I drove my wilson’s hard and that receiver did not break a sweat. i am very impressed by that receiver and it had been YEARS since i had listened to one. It actually made me question the rest of my set up. Very good piece indeed.
Yes i owned it. Good amp but runs too hot and they tend to go back to krell to get recapped because overtime the capacitors begin to leak due to the heat. 


The big update i have is that as many of you know, I find the weak link in my set up to be my preamp. I tried the c2500, classe cp800 and McIntosh mx122. So far, I feel I can get more out of the mc2301s. With that said, I have ordered the reference mark Levinson no52 preamplifier. This would be the most expensive component that I have ever owned at $30,000. Reviews are speaking as if this is the last preamp to own. I can't wait to hear this machine. 
Also, I will be taking a stab at the bel canto m600 monoblocks. These are class d amps and according to a good friend of money who owns far superior gear to what I own, he claims the bel canto will kill my mc2301s. I don't personally believe it but coming from his mouth is certainly enough to make me want to try them out. I don't personally like class d amps because I find them too fatiguing but I have not tried these and they are supposed to be amazing and smooth so here I go again. If these bel canto which retail at 6,000 per pair can take out the $24,000 mc2301s, this will be the biggest upset to my audiophile ears. I simply don't think this will be the case but if they do, I will have to completely redo my set up. 
Stay tuned, things are just about to start getting interesting. :)
Thanks guys. I am also very curious to hear all these. The mark Levinson no52 has certainly grabbed all of my attention and I can't wait to hear what it can do with these 2301s. I may also have a chance to try the no536 Levinson monos
which are even more money than the 2301s. 
Hi,
yes, multiple amps are always better than one single amp but you need to have a good power plant like a furman or a ps audio p10 which I really believe is the best power plant available. 
The brightness that you refer to is because emotiva and anthem sound indeed like that together with your speakers. If you need to warm things up a little then use an anthem amp or classe. I don't like any anthem amplifier that is not their statement amps. Stick to their statement stuff. 
i have always said, the c1100 is a great preamp and possesses a bunch of sound layers with great depth and width. It is also gorgeous looking. That said, there is something about audio research reference pieces that catch you off guard. I would go the audio research reference 6 route. I just feel it is an amazing preamp. 


quick update:

i unpacked the luxman 900u combo last night and i was not impressed at all.. I don't know if it was because these pieces were not being used for the past 3 months and it needs major warm up sessions or what, but the Mark Levinson 585 has the edge right now. 
I am in shock at how amazing this 585 sounds. I am not done with the luxman and need to keep it on for a day or so to see if it wakes up. Right now, my initial impressions are that it sounds way too laid back with my clx panels. I still need to use the wire world speakers cables with it and do another few tweaks before i come to my final assessment. 
The Hegel h30 is still in the box and will most likely be taken out tonight to see if the massive current it has will change things drastically or not. 
Quite a shock, but the no585 is SUPERB and does not get affected by crappy speaker cables. It just turns on and GETS THE JOB DONE RIGHT. 
I agree with rob. The audio research reference 6 or 10 are outstanding. I feel like McIntosh knows this and they are ok with it. They don’t want to top what audio research is doing. 

Anyhow, unpacked the Hegel H30 and I can already hear the extra horsepower. So far it sounds ver my controlled and work great depth. I left my house about 5 hours  ago and left music playing. I hope kings have changed a little when I get home. 
Rowland 925s: a bubble of sound that wraps behind your head and listening chair. The closest sound I’ve heard was the luxman 900u. Very similar but Rowland is a luxman 900u combo on steroids. That said, maybe what I’m hearing is the luxman 900u preamp through my 925s so maybe that is why I find it similar. Maybe once I get the Rowland preamp I’ll be able to differentiate better. 
I have zero desire to hear anything else. All My amps are dead weight at this point. 
The 925s are indeed marvelous. They have been playing music since last Friday and they will keep going until the end of the month. I don’t plan on turning them off. 
I plan on giving the cardas cables about 100 hours to settle since they are demos. I will then switch them out for the wireworld silver 7 and see what happens to the sound. I suspect I will prefer the silver 7s... just a gut feeling. 
Looking into a great opportunity for another set of speakers that came to me just now... stay tuned :) 
Tonight’s shootout:

Hegel h30/C900u Preamp: great slam and dynamics. Really good full sound with plenty of body. Mids are satisfying and highs are smooth.

Luxman C900u/M900u: More bass than hegel h30/c900u combo which is surprising since this amp is half the power of the Hegel.
The mids of this combo outshine the hegel’s h30. The highs are very very close but the extra ounce of silkiness goes to the luxman.

Overall i really like the Hegel h30. i will say that this amp has really surprised me. I really like what this amp is all about and the great horsepower and overhead makes it an excellent amp for those of you with monster speakers such as rockports, magicos, etc.
I can honestly say that the HEGEL H30 is the top contender to the pass labs x350.8. I wished i still had my x350.8 amp so i can compare. What a battle that would be. I have to say that the hegel h30 and pass 350.8 are neck to neck. If i am going to go on the performance per dollar route, the hegel is the clear winner hands down. 


I just took  the cardas out and put back the wireworld world 7 speaker cables and it gave more life to the Rowland components. I suspect cardas cables are no good with Wilson audio. Just too warm sounding and laid back.
Sorry guys- I discovered a bad panel on my clx speakers. I will have to re-evaluate things again once they are 100%. For now, take my feedback above as partially correct until I get everything sorted out.  I will report once my clx are back up and running. 
@avcr79 : hahah man you’re not supposed to paste things. I’m wanting to keep this thread more objective and less cluttered from how I first was doing things. 
So yes, the Rowland is just incredible. I actually want to listen to everything and anything through them. I also found out that the 925s May have only about 100 hours of total use from the previous owner ? This would mean they are still breaking in...
Quick update:
jeff Rowland Capri s2 just got connected and has been playing for about 20 min. Great synergy with the 925s but the luxman 900u preamp has it beat. Far more detail with the luxman 900u preamp. More things seem to show up in the music when uSing luxman 900u preamp. Will continue to listen. 
Sounds good. Right now the preamp added the “digital” flavor to things while the luxman kept the system sounding like tubes. Very smooth and detailed. It may have been that I was listening to my luxman preamp through the Rowland’s this entire time. I don’t dare to plug in my ref10 because I suspect it will make my jaw drop and I don’t want to keep both me 925s and the ref10.
Found out the Capri s2 is new. Never used. So far like I said, the luxman 900u sounds INSANE with the 925s. You’d swear it’s tubes. The Capri will have to massively change its tone and soundstage, Smothness etc in order to close the gap. That is a tall task to accomplish by any preamp. I just don’t see it happening but maybe the direction in which it shifts its tonality is better ? Not sure but I can say the luxman just oh man... it is just crazy amazing with the 925s.
as far as the wireworld platinum usb cable, it did NOTHING in my system. I could have bought a cable from radio shack for 99 cents and it would have sounded the same.
the only way I can justify this cable expense is because I’m getting the luxman d08u sacd/dac on Saturday and it will hopefully do a better job there. If it doesn’t then I’ll just close my eyes and think that I bought because I needed an expensive cable just because the rest of my system isn’t cheap but it won’t be because it does anything with my set up. 
Ok guys, I’ve asked several people about the following 2 set ups. Choose which set up you feel would sound better:

Rowland’s 925s
luxman 900u pre
luxman d08u dac/sacd player 

OR

rowland 925s
ps audio direct stream dac
audio research ref 10

where would you put your $???
Yes I agree with you techno dude... however, a friend of mine said he thinks the ref10 is just a monster and its tube magic and design will make up for the ps audios performance. He fees the gap in performance between preamps is larger than the gap beteeen the ps audio
dac and the luxman. 
Ok so I just plugged in the Ref10 and turned it on after not using it for about 2 weeks. I find the luxman pre STILL winning this race.... hmmmm. Is that shocking to anyone ? Granted, the Ref10 is still cold but i don’t find it better. The soundstage is bigger but it doesn’t have the midrange of the luxman preamp. I’m liking that these Rowland amps make it so easy for me to tell the difference as I change out components.
The Ref10 sounds more far back and the Luxman more closer to you. 
Of course Charles. I agree. But let’s be honest about something, how many of you go into a store and have patience to listen to a set up for weeks ? Most people walk in, listen for 15-20 min max and then go to another room and do the same and then You supposedly know what sounds best? How is what I do any different?
See the thing is most of us go to a store to listen to a speaker and come away with an opinion as to how it sounds but did you stop to think if the components were broken in ? Fully warmed up? Is there synergy with What you are hearing? Did they use the right cables? Too many variables as well to come home and know what sounds best. Do you know how many times I’ve listened to a speaker for 10 minutes and I felt that it was no good but then as I sat down and listened longer I realized it’s actually amazing? 

So the last update I want to give everyone is that the Capri opened up after I unplugged it from the p20 and plugged it into the wall outlet and used a silver 7 wireworld powercord. Not sure but it seems to have gained an extra ounce of detail and finesse. Will keep listening tomorrow.
Listening to the ref10 Again just now and yes the soundstage is bigger than the luxman or Capri s2. The luxman is narrower but it’s sweeter. At this level nothing is bad to be honest. It’s a matter of preference and flavor. Right now I feel like the luxman preamp is just better a better more engaging piece. The Capri is good but sounds a bit “muffled” or with a curtain in front of it. That said, I wouldn’t know this if I didn’t have the luxman or the ref10 right here. It’s an amazing preamp when you consider its price point. 
The luxman is just incredible. Yea I wish it did have the soundstage of the ref10 but the amazing sweetness and smoothness just makes me not even care. 
Well well well... I’m doing a shoot out between the chord Dave and the luxman d08u internal dac... hmmm you alll need to stay tuned for this one...
Mcintosh 2301 are indeed at the bottom. That’s the least appealing amp for me after hearing the audio research gs150, it killed my 2301s. Not even close and the 2301s have sloppy bass which the gs150 does not. 
Rowland 925s are great but it’s a chore to break them in. Some say 1,000 to 2,000 hours to break them in and well for me that’s a lifetime. I heard those with the Rowland preamp and it sounded good but not worth all the money they are asking for. 
I think their preamps are decent but nothing like your audio research 10. 
The best preamps I’ve heard are the audio research reference 6, Luxman 900u and then pass labs xp30. To me, these are the best preamps without having to spend crazy money. 
Yes but it depends on the rest of your components. Class a tends to sound clearer and more detailed. 
update:
i tried all 3 preamps with the Rowland’s and chord Dave and here is what my results are in terms of the best preamp with my jeff rowland amps:
1. Luxman 900u: amazing synergy. Incredible smoothness, liquidity, detail, outrageous mids. 

2. Ref 10: huge wall to wall soundstage. Good detail, good mids, but gets a bit bright sounding if cranked up too hard. The best overall soundstage but loses to the luxman in terms of sweetness. 

3. Rowland Capri s2: good synergy, detail, bass is awesome, amazing volume response. It gives you a good idea of the potential of the 925s but fails to fully deliver it. It also sounds as if there’s a curtain in front of music at times. For the money, this is one hell of a preamp. 

Overall, you can see that the luxman steals this show. Why ? Well it’s got much more synergy with my speakers and amps. If I still had my salon 2s, I wouldn’t be shocked if I’d still choose the ref10 but it’s a matter of system synergy. If I go back to Martin Logan Renaissance then maybe the ref10 goes up to the top. Who knows. 

As far as sources, the luxman d08u is just as detailed, clear and amazing sounding as the chord Dave plus it adds a world class sacd player. Its sound quality is more analog which adds warmth to the music that sometimes is needed. If you want a clear, analog like source with a reference sacd player then the luxman d08u is it. 
I select the chord Dave for me for 2 reasons:
1. It can be used as a preamp in I ever wanted to use it. 
2. Because it can be used as a preamp, it has far more volume than any other source I’ve owned. 
3. My Wilson speakers are a tad warm sounding so the added “brightness” the chord Dave has actually works for me. That said, if I had forward sounding speakers like focals, paradigm personas, klipsch horns etc then the luxman is what you need. 

HEGEL H30/ ARC REF 6 COMBO: I loved everything about this combination. Insane dynamics, smoothness, detail, clarity & resolution, big soundstage. I can now understand why the hegel h30 went up in retail value from 15k to 17k this year. 
I am really loving the synergy between these 2. What an immense wall of sound. What i find interesting is that the hegel h30 runs cooler than the arc ref 6 preamp. Yes, it runs amazingly cool and does not break a sweat. 

Luxman 900u amp/ arc ref 6 combo: the best midrange i have EVER HEARD IN MY LIFE has been presented by these 2 components regardless of any amp i have ever owned before. The luxman 900u with its spectacular midrange and the tubes from the preamp present a midrange that sounds better than if you heard a person speak in front of you. It almost feel like you can hear the saliva in the mouth of the performer. The highs are world class by all accounts and lack absolutely NOTHING. If you are a person who enjoys music purity, finesse, detail, high resolution and the last ounce of silkiness without any fatigue, this combo will make your jaw drop to the ground. This IS YOUR TICKET. 
It won't come cheap though because the amplifier does not show up often and when it does, it is gone in hours for over $10k. Far superior amplifier than simaudio 860a, plinius 103, pass labs 250.8 and possibly besting the 350.8 in resolution, clarity, but not attack since the 350.8 has more power. Getting a luxman 900u is like getting a ferrari without trying a mercedes amg, bmw m series, audio r8 etc. You completely leap over a ton of amplifiers.