ARC Ref 75 vs. Ref 75 SE


Has anyone had the opportunity to compare the ARC Ref 75 with the new Ref 75 SE?
hkaye
Do you ever get the feeling that ARC deliberately leaves out the circuit refinements that they end up offering for each of their models a year or two or three after each new model is introduced? As a cynical way to create business in between truly new models?
I can speak about the Ref 150 SE as compared to the "old" Ref 150. I upgraded my Ref 150 in March.

IMO, I think the SE upgrade effected an across the board improvement. I'd say half came from the KT-150 tubes and the other half came from the circuit changes. Bass is better defined. Better imaging and soundstage. Mids and treble sweeter and more open.

ARC charged me $5K for the upgrade. Pricey ... but I suppose it was worth it.

Hkaye ... take a look at Oregonpapa's posts about his Ref 75 SE. He's in 7th heaven.
HKaye-

these ARC upgrades are worth your money, only if, you plan on keeping the gear for many years. I have had the listening pleasure of auditioning the Ref3 SE, Ref5 SE, and Ref75 SE models. All offer an outstanding value and is better defined across the board. Keep me posted & Happy Listening!
IMO, If a product is upgraded to "SE" or whatever within the warranty period of the original, the company should upgrade the original for the difference in price.
Thanks very much for your response and for pointing me in the right direction (Oregonpapa's posts). I'm hoping to replace my VT 100 mk. II with a used 75 and then upgrade to the SE
I wondered why there were always so many ARC power amps on the trade-in shelves at Brooks Berdan Ltd. Sure, he was a VTL, Jadis, and Mac dealer, so there would be trade-ins, but why so many ARC? Brooks' tech Tom told me he was constantly repairing ARC power amps because when a tube blows in one of them it often takes with it some of the circuit board parts. The tubes aren't fused---ARC uses resistors and capacitors in that role!

Brooks preferred to sell the Music Reference RM200 as his $5k amp, with hand-wound transformers (the heart of any tube power amp), wound by Roger if you pay him extra! 100w/ch from a pair of KT88/6150/KT120 tubes per, power increasing with diminishing impedance, the opposite of a normal tube amp. It sounded very good to Brooks, and Fremer likes it enough to put it in Class A. And with it, no costly, frequent update/upgrades (or, as I like to call them, corrections ;-). Roger works on his designs for years before putting them into production.

Even if you really want a REF75, think about trying to hear the RM200. I love mine.
My REF-75 SE now has 375 hours on it. As soon as it hit 300 hours, it really opened up. My early impressions here on AG were for an amp that wasn't broken in. Take my comments I made before and add 30% to my enthusiasm for this amp. What more of a recommendation can one make other than to say that a product far surpasses one's expectations? In the many years of enjoying this hobby, I've had a lot of amps, both solid state and tube. They've ranged from modified Dynaco amps MKIII's and ST-70's (in the early days) to Van Alstine, to
Counterpoint, to Atmosphere and various ARC amps including the Classic 60, a REF-75, and now the REF-75 SE. Nothing so far comes close in my experience to the New ARC SE's.
Bdp24 ... you wrote "why so many ARC? Brooks' tech Tom told me he was constantly repairing ARC power amps because when a tube blows in one of them it often takes with it some of the circuit board parts. The tubes aren't fused---ARC uses resistors and capacitors in that role!"

Nonsense!! I have owned 3 and half ARC amps over the last "n" years: VS-110, VS-115, Ref 150 and currently, the Ref 150 SE.

Have tubes arced and taken out bias resisters?? Yes!! But how often?? Maybe once or twice a year. And since I've been using KT-120 and KT-150 power tubes, tube arcing has been a very rare occurrence.

Cost of repair is about $100. There's an ARC authorized tech who lives near me and who makes house calls.

Have other A'gon members reported very serious problems with the ARC amps? Yes, on rare occasion. But I don't recall the last reported occurrence.

Look ... if you want tubes, this is the cost of admission. Oh ... some might say other tube amp manufacturers use circuit breakers to protect the amp if there's a tube arc. True.

But ARC told me they prefer not to use circuit breakers because they believe it's an artifact they would prefer not to add to the circuit. Is that credible?? Haven't a clue. And frankly I don't care.

Cheers,

Bruce
And we can clearly hear the degradation whenever something unnecessary is put into the circuit. Just turning off the display lights on the ARC SE gear improves the sound. It becomes more relaxed and three dimensional. Who knows what switches intended to save a resistor in the event a tube blows would do to the sound. I guess if one hasn't experienced this phenomenon, its as though it doesn't exist. Go figure.

By the way ... There's 375 hours on my amp now ... and it really opened up at about 300 hours. Phenomenal amp.
Bifwynne, having an ARC repair tech nearby does make ownership of their power amps more reasonable. Imagine having to ship a heavy power amp to Minnesota every time a tube blows! In his writings on amp design and building-in reliability, Roger Modjeski made an analogy something like this: What if a car maker designed and made his vehicles such that when a tire blew (which is likely to happen) the suspension was sacrificed? And that this design choice was made because to prevent damage to the suspension in the event of a tire blowing, the suspension's performance was deemed to have to be slightly compromised. A fair and reasonable trade-off? That's for consumers to decide. Roger claims (of course) that his design protects the amp from damage by tubes without compromising it's sound quality. He states that the idea of using the circuit parts themselves to protect the rest of the amp from damage by it's tubes is just plain, bad engineering. Inelegant, at least!

Tom pointed out something else in the ARC amps---the burn marks on the circuit board, around the tube sockets. Mounting power amp output tube sockets on a circuit board = a very bad idea. In the mid-80's I went to hear Bill Johnson talk when he came to a local dealer. He mentioned that the ARC products were built with a projected lifespan of twenty years. At the time that seemed like an eternity---it doesn't now.

Of course, if you own ARC power amps and haven't had any problems, non of this matters. My history with ARC began in '72 with me turning on my brand new SP-3 pre-amp, fresh out of it's shipping carton. It immediately made a POP! sound, and I had my first smell of a fried resistor. Welcome to ARC ownership!
Bifwayne wrote....Have tubes arced and taken out bias resisters?? Yes!! But how often?? Maybe once or twice a year. And since I've been using KT-120 and KT-150 power tubes, tube arcing has been a very rare occurrence.

Once or twice a year?? You call that not too often. I call it unacceptable. Audio Research are not exactly new to the game.
Brf ... tubes arc. It's what they do. The problem isn't with the amp ... it's about the nature of tubes. The only fair push back point is that ARC doesn't use circuit breakers. I can't answer that question because I'm not an electrical engineer. All I can do is pass along what ARC told me. Take it FWIW.
Bdp24 ... I respectfully disagree with your views about modern ARC amps. I think your car analogy is ridiculous and simply not fair.

As to the mysterious Mr. Tom's comment, I don't recall ever seeing burn marks on the circuit boards of any of my ARC amps. Nor do I understand Mr. Tom's comment that mounting power tubes on the circuit board is a bad idea. Where else should they be mounted? Btw, is Mr. Tom an electrical engineer. Does he design and manufacture Class A electronics??

Just an fyi, ARC has been in business for over 40 years. That stands for something to me.

Your mid-1980s Bill Johnson story is not relevant. ARC gear has come a long way since 1985. And your anecdotal comments about the SP-3 are similarly not relevant nor persuasive. The SP-3 was first introduced in 1972 and was later modified several times in the 1970s.

Nowhere do you mention that you actually listened to modern ARC gear. So I'll ask you now. Have you ever seriously auditioned a current ARC Reference amp such as the Ref 75 or Ref 150, or the Ref 5 SE linestage?

Finally, I will conclude by saying that at some point, our hobby comes down to very subjective tastes. If you seriously listened to modern ARC gear and walked away underwhelmed, I would respect your opinion. However, bashing ARC for its design choices concerning bias resisters is just a bit over the top for me.

Cheers,

BIF

Bifwynne, Do you check the bias of your tubes regularly and replace them after about 2500 hours or so? The reason I ask is that seems awfully frequent to have problems.

I have owned ARC gear since the late 1980s. Everything from a D70 to my current Ref 110. In that time I have had a tube take out a resistor twice. And then once in the early 1990s I had to send my Sp9 to ARC because it would not come out of mute. That is it, no other problems. But I check my bias about once a month or so to make sure everything is fine. Tubes can drift, especially when the tubes are new.

Having a problem twice a year seems way to frequent.
Lostbears ... I may have overstated the arcing frequency. It really doesn't occur all that often.

Yeah ... I'll check the tube bias about once a month, especially with new tubes for the reason you said. Sometimes if I'm bugged about something, I'll check the bias just to take my mind off other stuff.

As far as tube replacement goes, I follow ARC's recommended guidelines. In the case of 6550s and KT-120s, ARC said 2000 hours. Maybe I'll went out to 2200 hours, but I started to get nervous that a tube might arc.

Kal told me that the KT-150s should run longer, maybe 3000+ hours. I need to recheck KT-150 tube life again with Kal. Frankly, I forgot.

Oh ... one practical point about biasing tubes, which I'm sure you already know. Tube bias readings can vary based on AC line voltage, which in turn can vary by region of the country and the time of day.

So after all these years of owning tube gear, I don't obsess about bias adjustments. I try to get the set tube adjusted to 65 mV, but I'll take 64+ mV as long as the slave tube is within spec (57 to 73 mV). If the amp sounds differently because of small bias voltage differences, I can't detect it.

Last point about repairs. I would be very circumspect about sending any of my gear back to ARC unless there was a compelling reason, e.g., a massive component failure or an important factory upgrade such as the SE upgrade. For small stuff like burned bias resisters, I call an ARC authorized service tech who makes house calls. The gear is simply too heavy to schlepp around.

If and when my tech retires, I would not be overly troubled to call another qualified tech who knows how to use a soldering iron. Bias resisters are not a high tech fix.

Other stuff, dunno. I'd call Kal and ask his advice. After reading about UPS and FedEx shipping horror stories, I'd really prefer to avoid the hassles.

Best,

BIF
There's nothing mysterious about Tom. He's been the tech at Brooks Berdan Ltd. for ages. He's in the shop on Wednesdays and Saturdays. The rest of the week he's employed at one of the TV studios in L.A.---yes, he's a professional engineer. Does he design and manufacture Class A electronics? Why---is that a requirement to point out what he feels are poor engineering choices? Of course, in his profession, reliability is taken very seriously. In consumer-grade electronics, he is very complimentary to Jadis and Music Reference, to name just a couple of companies.

Where should power tubes be mounted? On the chassis, as they are in those Jadis and MR amps, as well as Atma-Sphere's and others. Heck, even budget amps from the 60's had that! If you haven't seen burn marks around the tube sockets in ARC amps, perhaps it's because ARC owners seem to be constantly "upgrading" to new, improved models before the boards get singed from the heat---ARC tends to run their tubes relatively hard. The one's I looked at in the shop clearly had burned circuit boards. Which is bad enough, but what of the parts thereupon mounted? Heat can shorten their lifespan drastically.

The car tire/suspension was an analogy, not to be taken literally. Still, it's not that much of a stretch, IMO!

Yes, I've heard modern ARC products (and owned a couple until a few months ago. I still have the LS-1 I bought from Randy at Optimal Enchantment almost twenty-five years ago!). And yes, they sound great, but that's not the issue. There are many great sounding amps and pre-amps now, no need to settle for failure-prone ones. Are ARC power amps more likely to fail than other tube amps? Seems like it to me, just anecdotally. And though you may feel the bias resistor design in ARC power amps is acceptable, I consider it a ridiculous way to build an amplifier, I don't care how good it sounds. No, I don't design and manufacture Class A electronics.

But it's the constant, frequent, expensive, never-ending "improved" versions of each and every ARC model that disgusts me. ARC pulls the same stunt on every new model, leaving out the improvements that could have been incorporated into the original version (always increasing the power supply capacity, right? How many times can ARC "rediscover" that concept?), so as to generate new revenue from the same customer of the same model a year or two or three down the road (oops, another car analogy ;-), without having to sell him a new piece of gear. I'll bet THAT has played a significant role in keeping ARC in business for forty years. But ARC is doing fine without me---they have a loyal customer base, one whose members don't seem to mind being manipulated. Do I need to design and manufacture Class A electronics to have that opinion?

Sheesh, I didn't intend to ARC bash (though when pushed I obviously have no problem doing so), just to offer the tip above about a great alternative tube power amp, one that I prefer to own over any ARC. No, I haven't heard most of them (remember, it's not their sound I question), and couldn't afford them anyway. The Music Reference RM200 is available, by the way, with transformers (the heart of every tube power amp) hand-wound personally by Roger Modjeski, something I don't believe anyone at ARC is capable of doing. They don't offer that option, at any rate, no matter how much you pay for one of their amps. The sacrificial bias resistors, however, are mandatory, though free of charge. Until, that is, they need to be replaced.
I just now remembered another tactic ARC has employed that I find most objectionable---last one, I promise!

When the LS-2Mk.2 was being discontinued, ARC shipped their remaining inventory to select dealers at a discount, who then also sold them discounted. The ARC dealer in Orange County, California advertised the pre-amp and it's price, and included in the ad the fact that the remaining available LS-2MK.2's were ARC reconditioned pieces. Fine, all above reproach. The original price of the pre-amp had been $2995 (I've always loved the blank blank ninety-five pricing structure of ARC---very classy!), the close-out price $1995.

However, once all the reconditioned LS-2MK.2's were sold through, what did ARC then do? Why, they offered their remaining stock of non-reconditioned LS-2 MK2's at the same $1995 price! I don't know how you would feel, but I felt violated!! If they were honorable, ARC would have offered the remaining stock of both reconditioned and non-reconditioned LS-2Mk.2's at different price points (say, $1495 and $1995, respectively). Don't you agree? I vowed then to never again buy a "new" ARC piece, which I haven't. Who needs to?---there are so many used one's around!
ARC debuts gear implementing Tung-sol's new audio tube KT150. Customers clamor for retrofitting tube to previous generation but still current gear, ARC complies. Customers are happy with SE versions audio improvement...sounds reasonable. I can't comment about their past policies re upgrade path.
Model updates to facilitate use with a new tube is, of course, an entirely different matter, and most welcome.
Bdp24, you might not like the way ARC does business but from a marketing viewpoint it doesn't get any better. Sell the customer the latest and greatness and then 2 years later offer an upgrade for 2k to 5k. They have a loyal customer base which will fall for this most of the time.
Bifwynne says:

"Have tubes arced and taken out bias resisters?? Yes!! But how often?? Maybe once or twice a year. And since I've been using KT-120 and KT-150 power tubes, tube arcing has been a very rare occurrence."

That says it all!

I owned a D125 and a tube shorted. The amp went into flames shooting up six inches from the bias PCB. The dealer said that happened to 4 other customers. And they only sold 10 D125's in the era.

ARC sounds good, but the owners do not care about reliability! Most all other tube brands have better reliability.

I want failure free as the norm! Over the amps complete life!

Moved to Pass Labs Class A - better sound - no problems!
Don c55 ... No question about it ... Pass Labs gear has a great reputation. And I am glad that you are enjoying your Pass Labs amp.

But let's put your comments into a little perspective. The D125 was introduced in 1988 and discontinued in 1991. My goodness, it's been almost 25 years since the amp was discontinued!! There's been a lot of water under the bridge since the D125 was on the scene.

As I already mentioned, I've owned 3 and a half ARC amps in the last 10 years or so: VS-110, VS-115; Ref 150; and Ref 150 with SE factory upgrade. NEVER had a flame out. Burned bias resisters ... yes. Massive circuit failures ... never.

Btw, I also own other ARC gear: Ref 5 SE (linestage); CD-8 (CD player);and PH-8 (phono pre). Never had a burned tube problem, flame out or any other problem for that matter.

I think most of the crabbing in this thread goes to the inherent nature of tubes ... they arc from time to time. No getting around that. Of course, the other point is that ARC does not use bias circuit breakers. If it did, it would be a simple matter to push a button and you're back in business. Voila.

I surmise that cost cutting is not the issue here. Jeez, the Ref 150 SE lists for $14K. How much could little circuit breakers cost?? Either Kal or Len of ARC told me many years ago that the reason ARC use bias resisters was to minimize artifacts in the signal path. I'm not a EE, so I can't speak to the pros or cons of that choice.

Heck, if I knew my way around solder and a soldering iron, I'd replace the darn resisters myself. Just afraid of messing up my amp.

As I posted above, if after auditioning amps, one chooses another brand because it sounds better, then what can I say?? Or, if having to replace tubes or, on the rare occasional, having to hire a tech to fix a burned bias resister is too much hassle, then an ARC tube amp is not the amp of choice. Personally, I'm ok with ARC amps and other tube gear.
Bifwynne

ARC's service center is a profit center.

I have been to the factory, and the service team is large for a company of 80 employees.

The D125, although built around 1989, was touted as a reliability breakthrough, due to the addition of an LED on each tube, indicating a weak one, for replacement before failure. That was the only ARC amp ever made with that feature. Tubes can short at any time, especially near the end of life, with no warning. They later added timers to prevent owners from running tubes to failure.

I repeat: What other tube manufacturer has parts failure when tubes fail? It is poor design, and a lot of ARC customer do not care. Many give up on ARC in the long run. The internet forums are full of those stories!
Bifwynne: Why are you in every ARC post?

You are like Stringbean and VPI!

WE know you are a ARC cheerleader!
Don ... as I said in my posts, I've gone through a lot of ARC gear (linestages/pre; amps; CDPs; phone pre's) over the last 10+ years ...always moving up the line. From a consumer's perspective, I think I'm on solid ground about what I post because I have been there and done it with a lot of ARC gear.

Don, you may also notice that I do not shoot off my mouth about stuff that I have no hands on experience. I don't recall ever pissing on gear that I have never owned or auditioned.

If I catch an ARC thread and have something to add, I do. Likewise, if I catch an ARC thread that makes unfair, irrelevant, nonsensical, and exaggerated comments, I will also speak up ... just like I did here. IMO, ARC gear is worth auditioning. Underserved pejorative comments damage the reputation of a good company.

Sorry if I irritated you. And btw, Stan (Stringreen) knows a lot about VPI products. Folks in the market for a TT who are thinking about VPI would do well to read Stan's posts.

Have a great day.

BIF
Bifwynne

I have owned, and heard, ARC equipment for 40 years.

In the last 10 years ARC has changed the sound, since Johnson passed.

The older ARC gear has fans that do not like the current, over over the "Golden Oldies".

ARC now uses caps that take an absurd time to "form", and sound lean, and SS, compared to their older gear, IMO.

Have a good day!
07-14-15: Bdp24
Do you ever get the feeling that ARC deliberately leaves out the circuit refinements that they end up offering for each of their models a year or two or three after each new model is introduced?
I get the same feeling with Porsche 911 evolving 50+ years. Why can't they just build a 2016 911 back in 1950's and close shop?

I propose a new law companies only allow to build ONE model version and close shop. There are no innovation ... just ripping off customers.

As a cynical way to create business in between truly new models?
IMO, a company is offering what the consumer wants is smart business. An audio company not only produces excellent products but is operated to stay in business. The fact ARC has been in business for a long time speaks for itself.

The Music Reference RM200 is available, by the way, with transformers (the heart of every tube power amp) hand-wound personally by Roger Modjeski, something I don't believe anyone at ARC is capable of doing. They don't offer that option, at any rate, no matter how much you pay for one of their amps.
So Roger is the only person on earth that's skilled enough to wound a transformer to spec and he wants to charge additional $1000 for it? What does this say about his amps with transformer not wound by him? I guess he never had an issue with self image.

Why does ARC needs to offer a bogus option to rip off customers when stock transformer sounds fine? Are you serious?

07-18-15: Don_c55
Bifwynne

ARC's service center is a profit center.

I have been to the factory, and the service team is large for a company of 80 employees.
I've own many components and have learned reliability is as good as the service. Everything eventually breaks. ARC has one of the best service.

I argue most companies need to expand their service team so repairs don't take forever.

07-19-15: Don_c55
Bifwynne: Why are you in every ARC post?
Same reason you in most ARC post.

WE know you are a ARC cheerleader!
WE know you are a ARC hater!
OKAY ... full disclosure .. I am an "ARC cheerleader" and proud of it.

On the reliability issue ... I've had an SP6. An SP-14. a Classic 60, a REF-75 and now the REF-75se. I've had all of their phono stages from the PH-3 through to my present PH-8. I've had their CD players from the CD-3 through to my present CD-7se. I used the SP-14 until I upgraded to my present REF-3. I ALWAYS go for the upgrades ... and have never been disappointed with them as the improvements are always significant enough to justify the price of the upgrade.

In all of these years, and with all of this equipment, I've had only one resistor taken out by a failing tube and that was a KT120 in my REF-75. I took it to a fairly local tech who does ARC warrantee work. No problem other than it took a while getting it back.

In the meantime, I had my regular tech go through the Classic 60 and give it a good going over. He replaced the power switch (damaged in the '92 earthquake). He replaced the large capacitors because their measurements were way down. He said that this is normal in old amps. I've owned the CL-60 since the early 80's .. and never a problem what so ever, and the damned thing plays MUSIC! The CL-60 rests under a table in my listening room to be used as a spare. As old as it is, I can't bear to sell it. It just sounds too good.


Other than that one resistor, I have NEVER had a reliability issue with ARC equipment. All I've ever done is replace the tubes when they age. No burn marks on any of my circuit boards either.

I have a reliable source at ARC ... and he told me that they tested the KT-150's for over 5000 hours, on 24/7, with no failures prior to approving them for a replacement in the REF amps that were using KT-120's.

It always amuses me when some guys in these forums knock ARC products. I'm sure they are being very sincere in their assessments. But, here's a question for them ... Should ARC just stop improving their products and call it a day? Or ... should they continue with their R&D and offer upgrades to their customers who are willing to pay for them? Personally, I see nothing nefarious at work here on ARC's part.
I have ARC gear so I am not a hater. I was speaking to a local well known tech a couple of weeks ago and I told him what I had. I told him I had a current ARC preamp but I have been thinking about upgrading my older amp. He told me he feels the older ARC gear is built better than the new gear and also sounds better. I found that an Interesting statement from an authorized service tech that works on a lot of different well known product.
What I see is that typically, manufacturers come out with "new, better" products every two years or so. This to me is to keep their name in the papers and especially the magazines that review products. This is true for solid state and tube manufactures. Pass labs, Jeff Rowland, etc. Just because AR provides an "upgrade" to their products doesn't make this any different. I prefer the upgrade than a wholesale issuance of a "brand new and better" product.

The new and better product is really not, just new and different tubes, different capacitors, upgrades in the power supply, etc. But basically the same circuit design.

Also, the resale value of upgradeable products is higher than the resale value of completely discontinued products.

To me (in my humble opinion), it would appear wayyyy more disingenuous if a company came out with some new and better product and discontinued the other product after a year or so.

You have to get products out of the door eventually. To keep doing R&D forever would just be stupid in a business sense. So, some bright Engineer finds a better capacitor or better tube a year or so later. But the basic circuit design is very good. I would upgrade the existing product, instead of coming out with a new product that is basically the same.

In my opinion, the AR REF250 is hands down the best amp I have ever heard. I imagine the circuit design is the same for the REF75 and REF150. Why come out with entirely new amps? Add the simple upgrades, offer them to existing customers also, and move on.

I choose to not believe that AR would intentionally come out with a "subpar" product with the final intention of offering an upgrade later. What is the point of that? They could have just as easily come out with an "entirely" new product (that was basically the upgrade) and called it something else.

It is a great company, that puts many people to work and in direct comparisons with other "great" products, they are equal to or better. So, they are doing a great job.
The exception to the simple upgrade theory is the Mark Levinson 23.5. That was a wholesale upgrade that incorporated major changes. Yet Mark Levinson still considered it an upgrade and actually offered this upgrade to owners of 23 units. That too me was really cool.

Expensive, but cool.

enjoy
BIF---It's great to hear that your newish ARC power amps have been trouble free. Everyone (except Tim Paravicini!) seems to feel the tubes being made now are pretty darn good, with lower rates of arcing and shorting than in the past, which is especially good news for ARC power amp owners. Keith Herron even advises against tube rolling in his products, saying that while old tubes will change the sound, the new tubes (for instance the Sovtek 12AX7 he uses) provide lower distortion in his circuits. And I really like the look of the ARC natural faceplate with silver handles---very elegant and tasteful. They rid ARC's of the laboratory/industrial look black handles give them.

Bill Johnson had his Winter home only a few miles from me, in Indian Wells, the Bel-Air/Brentwood of the California Desert. He had Brooks out to his place to set-up his turntable, and Brooks, the dirty rat, didn't take me with him! Bill and his Audio Research Corp. created not only great sounding products starting in the very early 70's, thereby turning around the whole decline in sound quality that Hi-Fi was going through at the time (early solid state), but also created the market for high performance music systems. We all owe him an enormous debt.

And though HP and his TAS is often credited with introducing ARC to audiophiles, it was actually J. Gordon Holt who did so in Stereophile, reviewing the SP-2 and Dual 50 in 1971, the SP-3 and D-51 & D-75 the following year. High End shops starting popping up all over the country to sell the new gear, Walter Johnson (who now makes the Last record care products) starting his Audio Arts store near me in Livermore California. I'm still trying to recapture the magic of my first big system that I bought from Walt---Tympani's bi-amped with ARC power amps!
Knghifi- The Music Reference stock transformer is just fine. Excellent, actually, being an original Roger Modjeski design he has manufactured to his specs. But the art of transformer design, and hand winding them especially, is a dying art. Roger has made a lifetime study of transformers, and by hand winding his design he is able to extend it's bandwidth to a high frequency impossible in a machine-wound transformer---his, ARC's, or anyone else's. I have no idea how much difference it makes in the sound of an amp, and my system is too modest to warrant the extra cost. But it takes Roger about a week to make one, I believe, and a week of Roger's time, or that of any designer/engineer, is, I'm sure we all agree, worth a grand.
To me, the real crux of the ARC update/improvement matter is this: Let's say about ten years ago you had ten grand to spend on a pre-amp (must be nice!). Amongst your choices were the EAR-Yoshino 912 (designed by Tim Paravicini, a man very much like Roger Modjeski) and the ARC Reference whatever. The Ref, like all ARC products, has been updated/improved numerous times in the ensuing years, while the 912 remains unchanged. And the 912 STILL sounds better! How much has the owner of a Ref pre-amp spent to keep his pre-amp competitive? About the same as it's original cost? Hey, I'm just asking.

Now, look inside a Ref pre-amp, then inside a 912. The Ref chassis is stuffed with parts, lots and lots of them. Some may find this simple-minded, but to me it seems like the ARC designers have lost their way, and are just throwing everything but the kitchen sink into their electronics. Turntable critics feel the same about Harry Weisfeld's VPI designs. First one design, then another, then a third, each time claiming the new design is the best way to make a turntable. Every time ARC announces an update to a product, it is touted as being a drastic/huge/etc. improvement over the previous incarnation. You'd think with all the radical improvements, reproduced music would by now sound better than live!
Well, the flip side and potential benefit of the ARC upgrades to the folks particularly on this site is that you can probably buy the SE versions used and get a significant discount on both the unit and the improvements. Much like buying a McCormack Rev. Whatever amp -- much better amp at a relatively small premium to what a used original unit would cost. And like Oregonpapa said, nobody's forcing you to do the upgrades and the original unit would've cost substantially more if they offered it off the bat. Choose your poison, but I think giving consumers a choice in how much they want to pay for whatever performance is perfectly fine.
07-20-15: Bdp24
Knghifi- The Music Reference stock transformer is just fine. Excellent, actually, being an original Roger Modjeski design he has manufactured to his specs. But the art of transformer design, and hand winding them especially, is a dying art. Roger has made a lifetime study of transformers, and by hand winding his design he is able to extend it's bandwidth to a high frequency impossible in a machine-wound transformer---his, ARC's, or anyone else's ...
If the transformer is superior to anything on the market, why all the reported humming problems with RM200?

To me, the real crux of the ARC update/improvement matter is this: Let's say about ten years ago you had ten grand to spend on a pre-amp (must be nice!). Amongst your choices were the EAR-Yoshino 912 (designed by Tim Paravicini, a man very much like Roger Modjeski) and the ARC Reference whatever...
Then buy an EAR? Why are you so hung up on ARC? Who is forcing you to buy ARC? Where do you live? IRAN? Is there a new Obama / Robert mandate I should know?
An audiophile acquaintance has only recently completed his home trial period with an ARC REF 5SE / REF 75 combo, and has part Ex'd his previous incumbent EAR 912, much preferring the REF5SE, whilst giving serious consideration to moving on his, and In his words,

"Far less musical" 509's , the ARC combo are staying with him!
An audiophile acquaintance has only recently completed his home trial period with an ARC REF 5SE / REF 75 combo, and has part Ex'd his previous incumbent EAR 912, much preferring the REF5SE, whilst giving serious consideration to moving on his, and In his words,

"Far less musical" 509's , the ARC combo are staying with him!
I have a friend that has all EAR gear and he claims it's the best stuff out there. The problem is he never heard the reference gear from ARC or VAC.
I personally think he doesn't want to for the fear of liking it and getting rid of his equipment. And also if that happened he could not claim EAR as being the best.
07-15-15: Bifwynne

Have tubes arced and taken out bias resisters?? Yes!! But how often?? Maybe once or twice a year. And since I've been using KT-120 and KT-150 power tubes, tube arcing has been a very rare occurrence.

Cost of repair is about $100. There's an ARC authorized tech who lives near me and who makes house calls.
Bifwynne, do you keep track source of tubes that arc? Results will justisfy whether one should pay premium for ARC tubes.
Knghifi ... not really. The last couple of re-tubes came from ARC because the bias spread on power tubes sourced from a reputable tube vendor drifted too much. Btw, I may have overstated the times tube arcing has taken out bias resisters. I was being conservative and may have overstated the issue.

The main point is that power tubes may arc on occasion. The result cold be a blown bias resister. Also, at least with ARC amps, bias needs to be manually checked and adjusted on a periodic basis. This type of care and feeding may make ARC tube amps a non-starter for some. And that is a rational reason to consider another tube amp brand or a solid state amp.

In my case, it's not a big deal. I like the other pluses that ARC brings to the table.

Just saying.
07-26-15: Bifwynne
Knghifi ... not really. The last couple of re-tubes came from ARC because the bias spread on power tubes sourced from a reputable tube vendor drifted too much. Btw, I may have overstated the times tube arcing has taken out bias resisters. I was being conservative and may have overstated the issue.
I have 850 hours on orig KT120s in my REF250 so trying to decide where to buy the KT150s. $1600 from Upscale or $3200 from ARC. Hmm!

I already have NOS TS 6550s, Winged C and 6H30-DR so only need KT150s.

The main point is that power tubes may arc on occasion. The result cold be a blown bias resister. Also, at least with ARC amps, bias needs to be manually checked and adjusted on a periodic basis. This type of care and feeding may make ARC tube amps a non-starter for some. And that is a rational reason to consider another tube amp brand or a solid state amp.

In my case, it's not a big deal. I like the other pluses that ARC brings to the table.

Just saying.
Well, some people appreciate the precision of Ferraris, Porsches ... that requires additional maintenance and some only concern is getting from point A to B. :-)

I've had many different tube amps and they're all PITA compare to SS.
Knghifi ... that's a lot of scratch for tubes ... be it Upscale or ARC. Ironically, Upscale charges about $50+ for a KT-120.

If I have a "next time," I might check out a Pass or Ayre solid state rig. Both have earned high grades. In the meantime, I'm all ARC.
07-27-15: Bifwynne
Knghifi ... that's a lot of scratch for tubes ... be it Upscale or ARC. Ironically, Upscale charges about $50+ for a KT-120.
When time to retube, was planning SE upgrade but my mono already got some SE parts so will just buy the tubes. I'm leaning buying from ARC.

If I have a "next time," I might check out a Pass or Ayre solid state rig. Both have earned high grades. In the meantime, I'm all ARC.
Not sure how you listen but I've always had both. I usually leave my system on and when a great tune catches my attention, I'll go listen.

You should buy a SS amp. I like my Hegel H30. Checkout Luxman M-900U, Constellation ... The new PS Audio BHK is interesting. It's designed by Bascom King who also designed the Constellation Hercules. If SQ anything close to Constellation, it's a steal for the price.
Thanks Knghifi ... but my wallet is closed for now. I don't have the time, patience or interest to do an audio re-do. What I AM thinking about is signing up for Tidal and stream hi-quality digital in my DEQX PreMATE. Getting too lazy for the CDP and TT. Just want to relax in my cave and listen to my favorite tunes from the past. I like rock and roll music from the 50s, 60s and 70s that comes with harmony, a snappy beat and yes ... words.