Arc Ref 75se vs D'Agostino Momentum Stereo

    I have the opportunity to upgrade (?) to a D'Agostino Momentum Stereo for a good price. I was previously using a bought new  Ref 75 se which blew 2 tubes at the 30 hour mark. Despite being biased every 2 weeks. However, not only did the tubes blow ( due to the deterioration of the of the cathode coating of 2 tubes, I was told ) and the biasing resistor, it took a big chunk of the gold trace on the pcb and shortened the transformers as well.  This caused quite a stir between me, my dealer and Arc which took several months to resolve as I'm not based in the US. In the meantime, I was using a loaner ref 110 to tide me over. To make a long story short, just as my replacement 75 se (new ) arrives, I get an offer from my friend on the Momentums.  I have been traumatized by this experience so I was thinking of staying away from Arc power amps ( I've read some posts on similar problems ) hence willing to the try the Momentums.
     I am basically a tube guy so an SS amp even though the Momentums are suppose to be warm they don't have that tube bloom which I can't seem to live without.  I've been doing an A/B the last few days between the Ref 110(I know is' not the same without the kt 150's and all ) and the Momentum cause in case I get the Momentum's I can sell the Ref 75 SE sealed in the box as in "new".  I can seem to decide as both have their strengths and weaknesses. The rest of my system consists of

Ref 6 pre
Von Shweikert Audio Vr 44 Aktivs
Estoteric K07 sacd/cd player
VPI Prime with ADS and Benz Micro LPS-MR
IC's are all MIT - oracle and shotguns
PC's are all Shunyata alpha series.
Speaker Cables MIT Matrix 28
Room size 35 sq.m.

    Points I am considering, synergy among the same manufacturer's, the Vr 44's  are active so I don't really need a lot of power just enough for the tweeter and midrange. But those Momentums look gorgeous and the deal is quite good. From my recent A/B tests, IMHO I noticed that the ARC does better with vinyl while the Momentums does better on Cd and streaming from my macbook to the esoteric. Help me decide, your inputs are welcome. This offer expires in a few days so I have to decide quick. Thanx.
Do it.

You may swap back to ARC later, but will have had the experience of hearing a noted designer even if it is not ultimately to your taste.
So you received a *replacement* Ref 75SE and are going to sell it? Sounds like ARC went above and beyond normal expectations.

I have a Ref 75SE with no problems after several thousand hours. I would make sure the unit isn't enclosed in a rack or something which may cause overheating. My guess is you had a 1-off issue and you'll be fine.

You cannot go wrong either way.  In my view, ARC is the tube gear  closest in sound to ss and Dag is the ss gear closest to the sound of tubes. I mean this in a good way for both. Want transparency and grip?-Dag. Want bloom, dimensionality and a midrange to die for?-ARC. But neither is in any way deficient in any of the key characteristics mentioned above. I did an in house comparison a few years ago between a Ref 150 and Dag Momentum stereo with my Ref 40 pre. I came away all ARC but could just as easily come away with the ARC/ DAG combo. It all had to do with the type of music I favor that was overall more reliant on the characteristics at which the ARC excelled. Good luck. 
Appreciate all the comments.

           Truthfully, I wish I could keep both. But I can't afford to because of a few more minor upgrades I would still like to do. And the wife is watching me like a hawk.

          Yes, Arc did replace the Ref 75se to a new unit but took a while and if I'm not mistaken it was at my dealer's cost and not ARc's. I had my original 75se for 2 mo. The time it took to replace 6 months. Hence, the hesitation with further ARC gear. 


         I have reached the same conclusion as you have. It's like splitting hairs. As I mentioned to randy-11, I wish I could keep both.

I'd do it. Momentum on the REF 6 will be glorious, and it'll be all the tube goodness you'll need.

Besides, you'll be all set in case you ever want to upgrade from those Vandersteens...

This is getting more interesting as my friend is willing to take on my ref 75se plus $$ of course. But he doesn't mind if I open it and do a real A/B between the ref 75se and the Dags Momentum instead of the Ref 110.


           There is definitely tube goodness between a tube pre and ss power, but even more with an all tube pre-power. There lies the problem. In my case, I wonder if it's enough.
If it really is as close as "splitting hàirs" I’d choose the solid state amplifier. No tube maintenance or replacement of tubes to worry and you can leave the solid state amplifier on 24/7 if you want to.

The only advantage of the tube amplifier is if you believe it is better sounding and has sonic/musical qualities that the solid state amplifier is unable match.

I’ve recently done this type of tube and solid state amplifier comparison and although both were truly fine sounding across the board I ultimately preferred the tube ajp. It was more 3 dimensional , more tactile or palpable presence of the performers and superior tone,timbre, harmonic overtones and vibrancy (breath of life quality) Overall more emotionally engaging and "life like ".
This outcome may or may not be the case in your specific system and direct comparison. It appears that either way you’ll have an excellent amplifier in your home system. Choose the one that seems to pull you deeper into your music.
Attymbb 8-25-2017
I was previously using a bought new Ref 75 se which blew 2 tubes at the 30 hour mark. Despite being biased every 2 weeks. However, not only did the tubes blow ( due to the deterioration of the of the cathode coating of 2 tubes, I was told ) and the biasing resistor, it took a big chunk of the gold trace on the pcb and shortened the transformers as well.
I’m wondering if a possible contributor to the failure may have been the fact that your active speakers most likely present a very high impedance to the amp at deep bass frequencies. Which would mean that during notes having substantial deep bass content the amp would have been running essentially unloaded at those frequencies. And as you probably realize, as a general rule tube amps that have output transformers should not be run unloaded, especially when they are processing a signal. Otherwise damage to the output tubes and/or the output transformer can occur due to a phenomenon known as "inductive kickback."

I’m just speculating, of course, and I assume there are many audiophiles who use ARC Ref amps in conjunction with speakers of various kinds that have powered woofers. But it’s a possibility I wouldn’t rule out, and if you are looking for a tiebreaker in choosing between the two amps that might be a factor to consider.

Good luck. Regards,
-- Al

I own a Momentum Stereo s250 and would never trade for a tube amp. Tons of power with uber finesse and musicality. A modern work of art as well. I personally like my speakers to much to worry about a 'lightbulb' popping at high volume. Just my paranoia I suppose but when ARC described tubes as like light bulbs concerning failure that was it for me when ss is so very good now. 

          When I mean "it's like splitting hairs" , I don't refer to the sound they convey,more on the fact they both have their own strengths and weaknesses which makes the decision that more difficult.


          When my ref 75 se first blew up I had Harbeth SHL5+ then.

Well, of course, an all-tube chain will have more tube goodness, but to my ears, the benefits of all that extra power vs an increment in soundstage depth/width that the tube amp will provide is simply not worth the hassle of dealing with tubes in power amps.

As I said, you'll gain tons of flexibility and yours speakers (current and future) will thank you for it if you go with the Momentum!

I have heard both the D'Agostino stereo and mono momentum amps.  They are brilliant.  I love ARC gear but the D'Agostino was something special in sound (and a unique look too).  Music is supposed to be about enjoyment and you had a bad experience that will always be in the back of your mind.  Get rid of the worry and run the D'Agostino.

I'd jump on the D'Agostino myself if I had the means. 
Very good comments and perspective expressed here. My bottom line is follow your instincts and gut feeling. Choose the amplifier that seems to involve you more emotionally with your music. This is the one that will make you the happiest long term. You want the passion and emotion that music provides. 
Best of luck,

I also own a REF6 & 75SE - zero issues, sorry to read about yours - that sucks big time but in the end you have a New unit.

I've had solid state melt downs so anything is possible with any gear.

I have tried a few solid state including the DAG, very nice combo and I like tube pre and ss amp combo but once I put the 75se back in I find it just provides sonic's over all that no other combo does. The voices, instruments, holograph stage - more realistic base to me too where others can sound mechanical.

I no longer crave looking and just enjoy listening which in the end it's all about.

Obviously it's a personal call and there are so many factors that come into play including the rest of your set-up and your personal taste, I would like to add that I find I can play any type of music and enjoy where as with other combo's not so much.

I also have a Esoteric disc spinner - K-01 but mainly a vinyl listener. 

Have my 75SE placed upon a Sistrum platform, a great product and also allows endless air flow.

It's a never ending journey!

Tubes are more interesting, and I think they generally sound better than transistors (except for live pro sound reinforcement stuff, or I'm just lazy)…I recently stuck some extra tubes in a closed cel foam block so I could look at them instead of sticking 'em in a drawer (no, I'm not THAT obsessive…it was just a result of looking at a foam block and thinking, hmmm…). I like the sound of my single ended tube amp much more than any SS home audio amp I've owned (although I've used tube guitar amps since the 60s), and nobody, at least nobody I've heard of, casually rolls transistors in their SS amps ("Hey man, I just got some cool Texas Instruments MOSFETS I gotta try out."). However, If I could afford any SS amp out there, I'd get a Momentum because they look so cool…great design there Dan, and who doesn't like Bruguet watches?
I'd say get rid of them both. Since you prefer tubes go after them, just not tubes in ARC. Your hesitation reflects, I think, what I said - you don't want any of those for different reasons. Good deal or not is irrelevant, you have the means to buy great stuff to make you happy. So why not make oneself happy?
Additional thought is what doesn't sound great to your ears with analogue is worthless. I would suggest upgrading the turntable too, by the way.
Thank you all for your replies.  I really appreciate it. I've decided to keep the Ref 75se. As much as the deal was good, it became  more about the deal and the reliability issue of the ARC than the music which is also what inna pointed out. The Ref 75se was always my first choice, which is  why I bought it in the 1st place,  except when it blew up on me it got me  thinking twice about it's reliability.  No offence to Agostino owner's, it's a mighty fine amp, but I'm just really a tube guy and the synergy between the Ref 6 and Ref 75 is really good in my opinion especially for my taste in music .Either way I have to deal with ARC/my ARC dealer anyway since I also have the Ref 6. Now, if it blows up again I'll cross the bridge when I get there. Hopefully, it was just a one-off bad unit.  I rather the use the extra money for some planned upgrades like a long IC's from pre to power as I plan to move gear from up front to beside my listening position.

        A turntable is actually the 1st on my list  of next equipment upgrades ( most probably a clear audio innovation )  and maybe my phono stage ( I forgot to mention it above, it's a Simaudio 610 lp ) it's sounds great but the adjustment/dip switches at the bottom/under of the unit is driving me crazy. 
This is just the latest entry in the problem with ARC tube amps journal, from actual ARC owners. Then the "I have used ARC for years without one problem" owners chime in. As you know, not living near an authorized repair facility is somewhat problematic if you ever need to ship your unit back.
Yeah, I just suggested a more radical approach. At this level the service should be exemplary, without it it is even more overpriced stuff.
Source including phono stage must be very strong, cables and power cords too. Cables are components as well, some people just can't accept it.

jetter, your comments are misleading suggesting a problem with ARC.

One can have issues with any product, in the end it's how such gets handled and receiving a Brand New replacement is as good as one can get and why you deal with a dealer so they can deal with such. I would imagine there are allot of ARC pces sold - do you know how many comparing too % of ones which have issues. I do not read much if any issues - does yours differ because you make such comments suggesting so.

inna, do you not like ARC?, if not it's your own opinion and maybe best kept there as many others differ like myself. Have you ever had an issue with any pces you currently or past have owned and if so were they replaced with a Brand New pce - most likely not.

The Ref6 and 75SE is a amazing combo and this is coming from someone with allot of personal experience with different manufactures, one can read back dated posting of mine.

I agree OP can look at upgrading other components which will further enhance his listening pleasure. :) and yes many cables out there are the prices of components and then some - it's a never ending journey. 

Hi dev,

Honestly, I don't have a care one way or the other.  But as a reader of Agon posts, and only as a reader not a owner, I can say that I read about more problems with ARC amps (only the amps) than any other brand.  This is from what has been written from actual owners.  I don't necessarily agree that there are more ARC amps sold than other brands, just more than the uber expensive amps.  And I have read more complaints about how extravagant the cost to repair these amps are and ARC tubes than any other brand amps.  Believe me, I just don't care, if I wanted one I would buy one.  

Dev- do you prefer the ARC combo vs. SET on your AGs (presume you have Duo XDs now?). I've always enjoyed following your experiences from your Vac/MBL days...

jetter -  don't agree with your statement when you say:

"I can say that I read about more problems with ARC amps (only the amps) than any other brand."

That just isn't true.

keithr - thx - I just try to assist people coming from an actual owners perspective be it good or bad and I having owned said products or had in my system and not just sitting behind a screen pushing those keys away like so many do, I see some things just haven't changed.

I have an appreciation for numerous speaker designs and combo's and as you know I have owned numerous. This hobby is crazy in a sense because you will always be chasing your tail sorta speaking - it's a never ending journey, in the end what compromises are you willing to live with. What is important is too enjoy the music which can move you.

No I have not had any SET in house to compare but will eventually. Something about these two ARC pces and my AGs just work, currently there is nothing that bothers me - I'm just enjoying! The AG's offer allot of what I enjoyed about my MBL's but I really love the efficiency of AGs :)



You specified what the ARC pieces are (love ARC with Wilson); so what are AGs?

I also love Mbl. What Mbl have you had and paired with what?

Sorry to side track.

I have never heard a D'Ag but after being initially wowed by the bling factor you realize it looks like something your Italian grandmother would have had in her living room even if she weren't an audiophile.

And it's safe to say she probably wasn't.

Obviously art is in the eye of the beholder but I doubt that Agostino owners such as myself view the aesthetic design as anything other than a strong positive. Dan's just always has a strong sense of design from the inside out. As opposed to many companies audio, Agostino gives you the full package as well they should given the price. There are a lot of high dollar units available that have no visual appeal at all. Anyway just an owners opinion.