Anyone Compared ARC Ref 75SE and 75 With KT150


Appreciate any feedback if anyone compared 75SE and 75 with KT150s. I have purchased Ref 75 with KT150s and wondering if it makes sense to upgrade to SE.
Veerapaneni ... if Oregonpapa doesn't weigh in soon, PM him. He made the switch and is in love.

FWIW, I upgraded my Ref 150 to the SE. IMO, big time improvement.

I understand that the cost to upgrade the Ref 75 is about $2500 or thereabouts. That's about half the cost of the Ref 150 SE upgrade. Btw, the kit includes a complete retube.
I believe Oregonpapa bought a new 75SE but never upgraded his 75 with KT150s.
Veerapeneni ... before upgrading my Ref 150 to the SE version, I dropped in KT-150 tubes. There was a definite improvement in sound. Smoother, deeper and tighter bass, just better sounding all around. The SE upgrade effected another quantum level of improvement.

It's difficult to quantify such changes, but FWIW, Kal at ARC said that the KT-150s likely accounted for roughly half the improvements; the balance relating the SE circuitry changes. Who am I to quibble?
Veerapaneni ...

The KT150 upgrade was a definite improvement over the stock REF-75 in every respect. You wouldn't want to go back to the KT120's that were originally in the amp.

The SE upgrade is in another world altogether. Its simply an amazing amp. If you can afford to send your amp in to ARC for the SE upgrade, I would highly recommend it.

If I were you, I'd keep your current KT150's for spares and opt to have ARC install their own matched KT150 tubes. The tubes in my SE amp are more stable than were the aftermarket tubes I installed in my original REF-75.

Keep in mind that every piece of equipment, whether new, repaired or upgraded (as your's will be) is given a final listen-to by Warren Gehl at ARC ... and nothing leaves the factory until it passes Warren's muster. Your amp will be totally correct and perfect, including your new tubes before being shipped to you.

Let us know how you make out. You're in for a real shocker ... in a good way.

Hope this helps you out ...
Thanks oregonpapa. I will upgrade to 75se when time permits.
I have the 75 with KT150's at the moment. I will be taking it to my dealers in a couple of weeks, hopefully for an A/B comparison with his demo 75SE. I will report back when I have been.

In answer to Oregonpapa's post, I have had no problems with stability in the 150's I bought myself, no need for rebiasing to date. Incidentally, our local distributor is willing to make the SE upgrade without including the tubes, which he will keep for spares. It makes it a better deal.
Here's an excellent review on the REF-150se with a sidebar on the REF-75se.
Far from excellent I have to say, RG expending way too much article time blithering on about comparisons with a circa1980's D110, I feel that ARC would have been much better served enguaging the services of a reviewer more conversant with their recent Reference line amplification, most pertinently the Non SE Ref150!

Yet again we are not privy to the amount of burn in time on the clock, which as we are all too well aware may have significant impact upon performance at any given point, up to and beyond several hundreds of hours run time, thereby rendering RG's considerations on performance almost impossible to contextualise.
Happen to agree with Tsushima1.

I read RG's review. I quibble with Tsushima's use of the word "blithering" when describing RG's report. I would rather say blathering.

RG's comments that the internal cooling fans were "noisy'ish" is total hype. I cannot hear the fans from my listening position. IMO, a total non-issue.

And what really blew my mind was RG's comments about the aluminum cover adversely affecting the sound, e.g., increased tube microphonics and so forth ... total nonsense, ... bunk. I took my cover off and could not tell the difference. And btw, I do not screw it down because I check tube bias frequently. Too much of a PITA to get it off.

And finally, after all of RG's "to'ing and fro'ing" about this and that, he casually concludes (paraphrasing) that "yes, while the Ref 150 SE is a benchmark product, it's just one of many fine amps out there."

In his own words, RG writes "[t]hat uncanny combination of musical insight, substance and integrity is what makes the Reference 150 SE another genuine benchmark product. Don’t misunderstand that terminology. "Benchmark" doesn’t mean best. What it means is a product with the overall balance of musical capabilities that the competition needs to match or beat."

To his credit, Marc Mickelson ("MM") posted side bar comments in the RG review about the ARC Ref 75 SE. His bottom comments are consistent with what I think RG's review should have conveyed. MM said the following about the ARC Ref 75 SE, "[i]f you can live with its 75Wpc and balanced inputs (and you have a $10,000 budget), **I don't know of a better amp -- tube or solid state.**" (** = emphasis added.

I still recall reading the Stereophile review (with John Atkinson's bench test results ) of the Ref 150 (not SE). The review was stellar and read that way. FWIW, the Ref 150 (non SE) is still a Class A amp on Stereophile's List of Recommended Components. I imagine it's vaunted status will only be reconfirmed once Stereophile gets around to revisiting the Ref 150 SE.

Look ... some have accused me of being biased (pun) in favor of ARC gear. Ok, ... it's true. I admit to being a fan ... maybe even a groupie, but at the same time, I fully concede that there ARE many other great SS and tube amps on the market that folks should consider.

That said, I really thought RG's review left me with the blasé impression that the Ref 150 SE was "just another" ... ho-hum ... "great amp" on the market. IMO, it's much more than that. I believe that it is an audio classic that will be talked about like the ARC Ref 3 linestage, which I once owned and still think is a great sounding classic piece of kit. Is the Ref 5 SE better? Yes. Is it leagues and worlds and universes apart. No ... I do not think so.

Sorry for the long whiny post. For RG to even mention the old D115 in the same review of the Ref 150 SE was silly and a waste of print space.


P.S. -- I also agree with Tsushima's comment that it is unclear whether RG's amp was fully broken in. If not ... his review is totally useless.

P.S.S. Dennis Davis, a TAB editor just posted his review of the Sonus Faber Olympica III Loudspeakers. I note that his associated equipment includes the ARC Ref 150 amp.
"Warren Gehl listens to all the upgrades before it leaves the factory" for what they are charging that is the least they can do.
Well, I guess that one man's "excellent" is another man's "blither." No big deal really. What I liked about the piece was the sidebar info on the REF-75se. I thought the OP would find it interesting. Now ... I'm gonna go fix myself a martini ... and warm up my amp.

Happy listening guys ...
Here's another review:
Taters ...

Expensive? Yes. So are Mercedes Benz, fine cookware, Hickey Freeman suits, and beautiful women. Sometimes sacrifices have to be made. Me? I have fine cookware and ARC electronics. The rest, I couldn't care less about.

Happy listening.
I tried ref 75 with KT150 with my REF 250 with KT150. I did not like the sound of 75se with my high demanding Vandersteen 5a speakers..

I just got new GS150 and will be hooking up in couple of hours.
Veerapaneni ... your post is a bit cryptic.

Did you actually audition a broken-in Ref 75 SE? And you compared the Ref 75 (non SE w/KT150s) to the Ref 75 SE?? Not sure where the Ref 250 came into the picture.

Did you call Kal as I suggested to get his view on how the Ref 150 SE compares to the GS 150?

Your last post is not what I would have expected to read.

The circuitry in the GS 150 is very similar to the Ref 75 SE and Ref 150 SE. I am confused.

Frank ... you catchin' this??
I got an used REF 75 with KT150 tubes (not 75SE) which i compared with my REF 250 with KT150.

I also tried GS150 yesterday which sounds very good but i liked the sound of my 250s with KT150.

In both cases i liked my 250s . The only option for me to upgrade is to upgrade to 250SE now .

I noticed in your prior post from two days ago you said you just got a "NEW" GS 150,and today you posted you thought it was very good but not as good as your well broken in (I presume) ARC REF 250. All the ARC amps need 600 hundred hours on them to reach their full potential . Perhaps you might want to at least put a few hundred hours on the GS 150 and revaluate it . I know from prior conversations with several people at ARC, that they think the GS 150 is the best amp they have ever made. Of course once the REF 250 SE if finally released it probably will surpass the GS.
Why compare monoblocks with higher power (and cost)against stereo amplifiers with lower power (and cost) thinking it reflects on the absolute amplifier quality? The only thing that can be determined is which is a better match for the speakers being used.

And yes, the more powerful and more expensive amplifiers may be better by some definitions but that does not diminish the performance of the lower power/cost amplifiers when appropriately matched with speakers.
I thought waiting for 600 hours will not bring the quality I was getting from from 250s. I have asked my dealer to ship me 250SE and I should be receiving them tomorrow or Monday. Will post comparison of gs150 asp do 250se.
Veerapeneni ... as others have posted above, both amps must be fully broken in (600 hours) before doing serious critical listening.

Btw, did you ever speak with Kal. He is very familiar with ARC's products and can give a sense of what to expect.

Here's some Ref 150 SE comments. Last night I was listening to some old CDs of John Gardiner conducting the Orchestre Révolutionnaire (Canada) performances of Beethoven symphonies. IMO, the level of sound stage imaging, detail, tonality of sound was noticeably improved. Of course, my comparison is to my system pre SE upgrade/KT-150s and pre DEQX.

I attribute the improvements in large part to the KT-150/SE upgrade. That said, I can't ignore the possibility that my DEQX PreMATE also made a significant contribution as well.


Is that some sort of arousal stimulant you are on Bif ?
Regarding the break in time on the REF 75se ... I now have 530 hours on my amp. I haven't listened to CDs for the last half of this time. I've been enamored with the AT-ART9 and have been listening exclusively to analog. The other night I decided to go back to listening to CDs ... and I couldn't believe how much improved my digital (ARC CD-7se with the factory improved power supply) sounded. The first recording I threw on was a Harmonia Mundi sampler that I picked up at the CES in Las Vegas years ago. Its one of my reference CDs. To say that it sounded like a different CD is an understatement. They were in the room ... in the freakin' room!

This amp just continues to amaze.
When i am spending my money on new gear, the least i expect is that they perform better than my old ones from the get go. I am not saying GS150 is bad, they amazing but my 250s are driving my speakers better .

they might improve after breakin but i thought i needed more power for my speakers.
Veerapaneni ...

I've always considered that easy to drive speakers are the way to go. I'm presently using a pair of Legacy Signature III's ... 93db. The REF-75SE just coasts driving these speakers. In fact, the meters hardly move no matter what I'm playing. Also, I've found that many times, the lower powered amps in a product line can sound better than the higher powered spread. Not that I've always had easy to drive speakers. My old Accustat IV's come to mind. Great speaker, very musical ... but man 'O man what power hungry beasts they were.

I DO love the REF-250's, having heard them driving the Vandersteen 7's in the Optimal Enchantment room three years ago at the Newport show. All things considered, that was one of the very finest systems I've ever heard.

On expecting new gear to sound better than gear it replaces ... I remember when I first got my ARC REF-3. It replaced an ARC SP-14, a very nice preamp in its own right. I was a bit put off because while the REF-3 was better, it was just marginally better new out of the box. With the caps and tubes broken in ... the REF-3 just destroyed the SP-14. Same thing when going from my old, trusty, ARC-Classic 60 to the original REF-75. I love the Classic 60 ... now being used as a spare and soon to be sold ... but as the REF-75 began to break in, it was no contest. And then of course, the new SE versions are in another league all together.

Another benefit to the lower powered tube amps is the reduction in heat output. Southern California summers are HOT! Even today, this late in the year, our outside temps hit 100 degrees. The big amps would be out of the question in my room. I'm one who believes in turning off all electrical devises when listening to the system, and that includes the air conditioning.

Please don't take any of my comments as criticism in any way ... its just conversation between one ARC fan and another.

Take care ....
Oregonpapa---100 degrees? I miss those mild L.A. Summers ;-). I'm out in Palm Desert now, and we regularly get up to 115-117. My monthly electrical bill (which includes the operation of the house's air conditioner) this Summer has been $500! I sold my pair of mono power amps because each had eight output tubes each.

Good recommendation of the Harmonia Mundi sampler. What a great, great label, whose catalog contains fantastic music recorded in excellent sound. In the late 80's/early 90's they held Sunday parking lot sales at their Santa Monica office, where they were selling off the last of their American and French LP's, for $5 each!
Thanks Oregonpapa. I have no doubt both 75SE and GS150 are very nice Amps. The difference between Gs150 and REF250 was very marginal and if i had high sensitive amps i would have definitely got 75SE instead. But my speakers shine with more power.
Bdp24 ...

I had friends who used to live in Palm Desert. When visiting them in the summer it was a constant round trip... from the air conditioned house to the pool. Then from the pool to the air conditioned house. My friend was a lineman for Edison. Can you imagine climbing Edison poles all day in that heat to repair electrical lines? He said that one gets used to the heat once one's blood thins out. Jah ... right!

I remember those Harmonia Mundi parking lot sales in Santa Monica very well. My friend Warren and I used to score big there. Some of my favorites are the Kapsberger Lute sonatas with Paul O'Dette, the Handel Water Music ... and for fun, La folia.

I wish we could get those for 5 bucks again. I scored a bunch of used Harmonia Mundi CD's at a record store in Pasadena once for $2.98. I bought most of what the store had ... probably 25 or so. As I was scooping them up, I remember that I kept thinking ... who in their right mind would trade in their Harmonia Mundi collection? And of course, what store would be dumb enough sell them for $2.98?

Guys like us can really make out sometimes in used record stores that know nothing about classical and/or great old jazz. Sometimes the guy behind the counter pricing the new arrivals only knows rock, metal and rap .. and he/she looks at a Harmonia Mundi lute record, or an original Count Basie w/Sarah Vaughn record as crap. Hee, hee ... little do they know.

Harmonia Mundi was an interesting label. Like you said ... great sound and interesting music too. On many of their recordings, they used musicians who were expert at playing the ancient instruments, so what we heard was what Handel and Mozart heard. They recorded a lot in some of the old stone churches in Europe to get those great acoustics they had. You're a fan, so I know you're aware of how and where the label recorded, but for others reading this, give the Harmonia Mundi label a try. You won't be disappointed. The CDs are really, really good. The vinyl is great.
Right you are. HM has some of the best of the Period/Original Instrument/Historically Informed (choose your favorite term!) musicians, singers, and conductors in the field, Nicholas McGegan, Philippe Herreweghe, William Christie, and Rene Jacobs amongst them. A great label for Early and Baroque music. The Handel Water Music album is an excellent album to try first.
I took my 75 to have the SE upgrade, to my dealer today. I was able to compare a run in 75SE, with my 75, re tubed with KT150's, but otherwise unmodified. It was with a CD6 CD player, Ref 5SE and Wilson Sabrinas

I didn't have hours to make the comparison, but there was clearly a difference, which I would characterise as more of the same. The same deeper tighter base and better clarity and grip, just more of it. Ideally you would have had a REF 75 with KT120 tubes as well, but that is probably asking to much.

The Wilson Sabrina's really are very good indeed, by the way and I am not a Wilson fan. I have heard them with ARC and Constellation amps and they sounded great with both.
It sounds as though the demo session re-assured you in your decision to go with the SE upgrade David, Guilford Audio ?

For my part, My new REF250se's were last spotted in a Pedalo off the coast of Nova Scotia heading East!
I received my 250SE Amps today. Will hookup in the morning.
Yes it did and yes it was Guilford Audio. I was speaking to Trevor yesterday and he was very impressed by the 250SE. He thought you couldn't tell it from a large SS amp, in terms of grip and base control. It goes without saying it should best a SS amp for sound quality.
An Interesting comment there David, Trevor knows his ARC stuff, a most excellent dealer IMHO.