Then there were 2


OK I have 3 amps on my short list but one is not available due to supply chain issues.They are ARC Ref75SE, Rogue Stereo 100, (and not available is Quicksilver Mono KT/120)
Question sin it is down to the Rogue and ARC are the comparable (or as they say a coin flip?) or is one considerably better than the other.
I like the fact that the ARC use KT150 and the bias is accessible on front panel.
jimbones
I'm not familiar with Rogue but if it were my money, I go with ARC. The Resale value is better and I know it has great sound quality.   ARC has a sound quality reputation that has spanned decades - they aren't going to ship second hand sound.
Rogue makes good stuff.  I had the M-180 monoblocks for a long time and they were great.  I own a couple of ARC pieces, but haven't heard the amp you're looking at.  If buying blind, I'd lean towards the ARC.  I would expect it to be just a bit more refined and as mentioned, it's going to have better resale value.
of the two, I would choose ARC

however, I much prefer the Quicksilver Mono 120's, and think this:

Pair of Quicksilver's, with KT150's is under $5,000. 

ARC is $10,000.

I would wait forever for the Quicksilvers, and use something else in the meantime. However long you wait, it is but a speck of time.

Two mono amps can be moved by one person, more placement flexibility, different cable lengths, ....

You could buy a used pair of mono blocks now, use them, sell them when the Quicksilver finally materializes.
elliot that was my preference as well, however they are hard to find used. QS has discontinued them. I agree with your points. The Ref75SE is not too heavy at 47 lbs.
@jimbones What loudspeakers are you planning to use and how big is your room?
I checked, I also saw no used quicksilvers, that tells you something!

My job designing corporate office space, projects typically 18 months start to finish: I told my employees part of their job was to keep me from compromising under pressure. It's always a war against the forces of compromise.

Not that ARC is a compromise as much as: In 3 years, what do you want to wake up and see/hear in your system?

I meant buy anything interesting used or new that you are confident you can re-sell when the Quicksilvers FINALLY arrive. 

For the difference in price too many options exist,

pounds is usually transformers, heavy oversized parts. two quicksilvers at 82 lbs or 1 ARC at 47 lbs?

Personally I like the look of the quicksilvers more, and, think thru the use and related costs of existing or new cables: the different lengths involved if monos or stereo.

it's a fun problem to have, best of luck deciding.
My reaction is exactly the same as @atmasphere . What are the speakers will you be pairing?
Do not underestimate the Rogue Stereo 100.  It is extremely "clean" with a low noise floor, very good detail and articulation.  Although it is a tube amp, it is not overly warm and is definitely not "diffuse".  I had one paired with Sonus Faber Amati tradition speakers and it was extremely good.  I traded it for the Rogue Apollo Dark Monos which are truly spectacular.  (Primary reason for trade was I felt I needed the extra power and wanted to make the next step in terms of articulation, lower still noise floor, etc.) Rogue is a quiet company. Mark Obrien is a genius in design and is nearly always available by phone to answer questions, discuss the components, etc. Fantastic support.
@craig I own an RP7 so I know how accessible Mark and Nick are. Very good company to deal with. I find their stuff a little to much like solid state, i am getting used to it. I did demo the QS and a VTL in my system and it was very good.

@elliot I am using my own 2 way speakers two MW16P and TW29R Satori drivers. Room is 14x22x7
rogue might be quite good but for my dollar i would go arc if the cost is not a deterrent
One thing to note if using the RP7 as a pre, (from Stereophile's measurements):

" As a result of the increased output impedance at low frequencies, the RP-7's response drastically rolled off below 400Hz into 600 ohms, reaching –3dB at 200Hz (fig.1, cyan and magenta traces). The RP-7 should not be used with power amplifiers having an input impedance much below 30k ohms. Into 100k ohms, however, the RP-7 offers a flat, wide-bandwidth response with an upper –3dB frequency of 170kHz"

Keep in mind the input impedence of the power amp you will be using with it.  I have an RP7 and a Stereo100 and the match is lovely, as it should be with the same brand.
Go with the ARC, better sounding, higher resale value, etc.  The Rogue is for value consumers, the ARC is for music lovers.
my own 2 way speakers two MW16P and TW29R Satori drivers.
Is that between 2 cabinets or just in 1?

Do you have any idea of the efficiency and impedance of the speakers?
In a room that size 100-130 watts will work if the speakers are 92dB although you'll be able to run the amps out of gas if you really push it. If the speakers are 4 Ohms you might need more power.
@yogiboy yep spoke to mike, he has a new model called KT mono but he cant deliver due to parts shortages. V4 also toast.
@atmasphere i estimate the efficiency at 90db-92db. There are 2 woofer in each cabinet. The woofers themselves are 90db. but with 2 in parallel it is higher but I dont have exact measurements of efficiency. speakers are 4 ohm.
@yogiboy Are you sure the M120 is not available? Did Mike tell you that? http://quicksilveraudio.com/products/mono-120/

90 days ago he was backordered with a backlog of customers. Not sure now, someone would need to ask him again for an update. I’ve had five different people unsolicited reach out asking me if I’d consider selling mine. Demand seems to be greater than supply at this time. They are worth the wait if you can.
a pair of mono 120 sold in 56 minutes the other day once posted on Audiogon. It was posted at 9:52pm and I got home at 10:50 and it was sold.
this is wierd my post did not "post"
lets try this again: Input Impedance
ARC 300K balancedRogue 200K (not specified)QS 100K single ended
ARC should be fine
There are 2 woofer in each cabinet. The woofers themselves are 90db. but with 2 in parallel it is higher but I dont have exact measurements of efficiency. speakers are 4 ohm.
@jimbones Tube amps do not double power as impedance is cut in half. That is why efficiency is a more useful spec than sensitivity when tube amps are involved. In this case, while sensitivity does increase, the efficiency remains the same. Since the total wattage of most any tube amp is lower into 4 ohms, I think you will find that you simply need more power.

I would also consider putting the woofers in series rather than parallel. They will act the same in the enclosure although you'll have to change your crossover a bit. But a tube amp will thank you as it will make more power, have wider bandwidth (particularly in the bass) and make less distortion.

@atmasphere good point, will do. Or maybe just make it a 8 inch 2 way 8 ohm speaker.
@jimbones Well then its 8 ohms, but the efficiency in all cases remains the same. I think you're better off with the dual woofers, because you have more surface area for making bass and less excursion. Putting them in series works great for tubes.
Ref 75 SE over QS 120mono over the Rogue 
I started with Rogue  when I upgraded it was between Ref75 and Aesthetix Atlas went with Aesthetix 

Enjoy the Music 
Tom
QuickSilver V4’s over the ARC, I have first hand experience with both brands and value QS is a no brainer but also a very good sound and super reliable.  My GS150 was short lived and quality with the new ARC is questionable along with customer service.  I have friends that are dealers for both and QS is their pick to own.
Audio Research in my opinion is unquestionable the superior choice. Incredible sound, build quality over decades. Exceptional valuable over time. Also, I had recommended Rogue to a friend a long tine ago, the amp blew up during the warranty period and the owner would not repair it. I will never get over the humiliation of that recommendation.
I've had ARC pre & power amps for years and have found them to be reliable and very musical.  I've also not experienced any service issues with them.  The Ref 75 is a fine piece of kit, but I'd look at going up a step to the Ref 80s.  There is a used one for sale here on Audiogon.  The audiobias is nice and the look is a bit more modern.  
ARC.

In addition to what everyone else has said, they’re service is great.

All the best.

JD
ARC

Why settle if you don't have to?

Hope you are auditioning Magnepan speakers IN YOUR ROOM before you make a final speaker decision with your ARC amp and, hopefully, matching ARC pre-amp.

Prepare to be amazed!

Cheers!
@richopp who said i have Maggies? I do not consider ARC settling (other than power output.)
@ghdprentice , I hate it when that happens.

Wire the woofers in series, adjust the crossover and get the ARC. Next think about subwoofers. You can make them yourself for smart money.
@ jimbones: interesting audiogon user handle name.  I know there is more than one person named Jim Bones out there in the world..... but by any remote chance are you  'Jim Bones' the large format nature & wilderness photographer?  

probably not.. but had to ask.  That would be way cool.

sailboat
@sailboat, no I am not. I got the nick name Bones from a lot of physical injuries doing advanced skiing, downhill ,mountain biking and playing ice hockey goaltender for over 50 years. I like to think of myself as Humpty Dumpty Lol
ARC is point to point vs Rogue circuit board?  I could be wrong but I have owned a Cronus Magnum II and a VT-60.  Sure miss the VT-60 but the Cronus not so much.
@mijostyn will it really make that much of a difference going from parallel 4 ohm to series 16 ohm? What would expect the difference to be when listening?
Hello,
I was wondering if the Rogue DragoN would work. It’s 300 watts. You will still have the RP7 to produce that awesome sound you like. Also, you might want to try the RP9. It is on another level compared to the RP7. Add the DragoN to that and your done. I am not sure if you are near the Chicagoland area but this dealer is close to me. https://holmaudio.com/This store lets you demo in your home. 
@hshifi You had already suggested the Rogue preamp, I purposely decided on the RP7 as it lets me tailor the sound a bit via tube rolling.
I dislike Class D, never heard one I liked. I don't want SS as I already have one I am keeping (for the time being) This is purely a tube play.
 I am totally in the ARC groove...have seven of their pieces. It's a long strange journey but (not for nothing as they say) I have had my mid-range amp used to power a mastering system playback and it stood up remarkable well against custom Levinson amps.  That's my take on it.
Regards,
barts
Post removed 
I have the REF 75SE, formerly had the REF 150 nonSE and Classic 120s.  This is the best amp I have had including several solid state before getting into ARC.  My only Rogue experience was the Ares Magnum phonostage.  I was very disappointed in comparison to ARC's phono stages and that would make me expect ARCs amps to better theirs as well.  My speakers are the Wilson Audio Sophia and it drives them very well.  Outside of a poor speaker match I cannot imagine you being disappointed in the 75SE.  Good luck!
The VT80SE seems similar to the Ref75se so I would expect that to be a good alternative 
ARC is point to point vs Rogue circuit board?
Huh? That's news- I've never heard of a hand-wired ARC product. All that I've ever seen have employed circuit boards.

i think point 2 point vs. a PCB is the absolute last thing to worry about…..


@tomic601 I agree. I have been told the KT150's make a big difference. I'll be patient I have a number of choices that I have whittled down to QS and ARC. I would only buy the Rouge if I can demo it.
@jimbones 

thanks for responding.  appreciate it.  if you get a chance you should check out the other 'Jim bones' work.  he is an amazing photographer.  you might enjoy it.

sailboat