audio research REF 150

Does anyone have a audioresearch service manual?

01-03-15: Adg243
I bought ref150 2 weeks ago and at 38 tube hours could not be happier. And many people are saying it will get better at 600 hours ! Boy oh boy

Congratulations! I have 330 hours on my Ref250 and it sounds excellent.

What color is the capacitors in your Ref150? In mine, 4 of the 6 small ones are gold and big ones are all white.

I bought ref150 2 weeks ago and at 38 tube hours could not be happier. And many people are saying it will get better at 600 hours ! Boy oh boy

The Ref 5 SE preamp and Ref 150 amp were bought at same time replacing McIntosh C48 and MC302. System has now much better definition across all frequencies. I think "High Definition" moniker on the faceplate was actually delivered with flying colors. Very wide soundstage, a lot of 3D, very detailed highs, enjoyable decay on guitar strings and cymbals. Can hear bass drum at the background of group of musicians. Amazing.

MCD500/Mac Mini > Meitner MA-1 > Ref 5 SE > Ref 150 > Sonus Faber Amati Futura. All cabling, power distribution uses Nordost/Valhalla version 1.

Ollies ... I assume by your reference to "this power amp" that are referring to the Ref 150. If so, I am puzzled by your question because KT-120s come standard with the Ref 150.

Although there may be other companies that manufacture the KT-120 ... the ARC standard issue *IS* Tung Sol, a redo by the Reflektor company in Russia. The 6550 does NOT come standard with the Ref 150.

Perhaps I do not understand your post. If not, please explain.

has anybody tried the tung-sol kt 120 or 6550 in this power amp I have 1500 hrs may need to change soon

Good evening .

I have been having a little "FuN" switching the output taps on a REF-150 driving Martin Logan CLX's and find myself concurring with a post made by another member , sfischer1, earlier in this thread ~

"11-21-11: Sfischer1
Just spent a couple full days using a demo 150 with my Martin Logan CLX full range electrostatics. Even though the MLs have a tough impedance that drops to an ohm at high frequencies, the best sounding tap by a large margin was the 16 ohm connection"

Considering the CLX's nominal 6 Ohms impedance dipping down to 0.7 Ohms @ 20K would not our subjective findings contradict the recommendation made by John Atkinson contained within the Stereophile review ~

" All taps behaved similarly when it came to the maximum output power. Into a load twice the nominal tap value, the Ref150 clipped (defined as 1% THD) at 90W (19.6dBW, fig.4). Into the nominal tap value, it clipped at the specified 150W (21.75dBW, fig.5), but with a higher level of distortion. Into half the tap value, the amplifier clipped at 80W (13dBW, fig.6), but with even higher distortion at lower powers. It is important, therefore, to use the transformer tap that best matches your preferred loudspeaker."

" with the caveat that it performs at its best with loudspeakers that have impedances equal to or higher than the nominal output-tap impedance.—John Atkinson "

Where is that 'confused' emoticon when one needs one !

Ref 150 post -- Thought it was worthwhile to share one more quick reaction.

Was listening to Von Karajan conducting the Berlin Philharmonic performing Brahms 2nd and 3rd Symphonies (DG redbook CD). Let's just say that Brahms must have been feeing real good when he composed these works because when well performed the incredible dynamic range and mix of instruments could easily overwhelm any system. I was extremely impressed by the poise and control that my rig had over the music.

Not sure if the Ref 150 gets all the kudos or ARC system synergy deserves some too. I suspect the amp deserves the lion's share of the credit though.

Btw, I'm running a little experiment with the "redbook" CD side of the house. I order Gold and HD XRS (?? thinks that's the designation) quality "redbook" CDs from Acoustic Sounds (one each). These designations are supposed to show that the CDs were mastered and produced with lots of TLC and are supposed to sound better. I should receive the CDs in a few days. I'll post my comments here and on one the digital quality threads.

Ref 150 update: still loving the amp.

I continue to be impressed by the amp's ability to negotiate (if that's proper audio-speak) complex musical passages and effortlessly handle transients. The dynamic headroom is just fantastic -- I guess that speaks to the upgraded 1000 joule power supply. Double the Ref 110's.

Even though bass slam and low end extension is somewhat better off of the 4 ohm taps (probably because it's the lowest output impedance tap), as I've posted elsewhere, so far, I think my speakers sound their overall best when plugged into the 8 ohm taps.

3-D imaging and soundstage are eerie. My speakers are just about invisible. Imaging seems to be about 2 or 3 feet behind the speaker fronts and I can almost discern where voices and instruments are located. Overall acoustic presentation is excellent.

If you're in the market for a tube amp, I highly recommend this amp. Just a caveat. As I have also commented elsewhere, electrical compatibility with your speakers is key. Do your research and try to audition a like combo if possible. There are many threads running about this issue.

Cheers,

Bruce

Ref 150 Update: Been listening to a variety of music from both CD and LP sources. Currently listening to von Karajan conducting Berlin Philharmonic, performing Schubert's 8th and 9th Symphonies (DG) on my CD player. I will dispense with the usual audiophile superlatives and simply say WOW. Outstanding!! That's it.

At first I felt guilty for dropping the cash for the Ref 150 for all the obvious reasons, especially since I always thought the ARC VS-115 did a great job. Why improve great?? Well ... there's great and then there's GREAT.

Also, let's face it. How long are any of us going to be around I rhetorically ask? If audio is my worst sin, but it makes me happy, why not splurge a little? It's not like I bought a Stingray when I already own 3 other top end sport cars parked on the street.

Well, the Jewish High Holidays are rolling in next week. Might be an opportune time to confess buying the Ref 150 along with my other 613 sins and hope I'm granted atonement. For all I know, when I knock on Heaven's door, an Angel might tell me to come back. The Heavenly Court is taking a music break, listening to its new Ref 150 pounding out Schubert's 8th and 9th. LOL!

Happy New Year to my fellow MOTs and my best to everyone else.

Cheers

I went to a local dealer recently and had the chance to compare the new VSI75 integrated, Reference 75 and reference 110 with KT120 valves. I was hoping to get away with an integrated instead of the Reference 75, as the former is said to have similar circuitry to the ref 75.

All were played through Wilson Duete speakers. There was a very clear difference in sound quality, with marked improvements at each point.

The VSI 75 was clearly inferior to the others, in detail, soundstage, it was grainy and muddy compared with the others.

Next was the 110 with KT120 valves and much closer to it was the Reference 75, which was a clear though not night and day improvement, over the older, but more expensive model. I have the Ref 75 on order.

Congrats Bruce.
Good luck with the Ref 150-----a real keeper.

Randy

Finally took the leap. Picked up a preowned Ref 150 a few days ago. I'll spare the Forum with the usual audiophile-babble in describing the Ref 150. Suffice to say that IMO the comment in ARC's sales literature that the Ref 150 "dominates" one's speakers is credible. As good as my VS-115 is, and it IS a fine amp, the Ref 150 IS in another league. As Tony the Tiger used to say, "it's great!!!"

Bruce

P.S. Spoke to Kal about a Ref 150 tech issue yesterday. During the call we touched on how the Ref 150 compared to the VS-115. I commented that while the Ref 150 is a great amp, the VS-115 is also a fine amp at its price point. Kal agreed and mentioned that ARC crammed as much technology and high grade parts as the VS-115 chassis could hold. That's an fyi for anyone looking to break into trying a high-end tube amp at a relatively affordable price. bif

@Cmalak - interesting point. In some ways, ARC seems a company that is clinging to its mom-and-pop identity even though its an international company.

Whatever, though. They make beautiful products that know how to make music be as lifelike as possible

I'm with Cmalak. Pinkus must have an ax to grind as his comment contributed nothing to the op's question. Furthermore, the improvements in the last few iterations of ARC ref amps and preamps have been quite significant and all for the better.

@Pinkus -- is your reference (pun) to the Ref 180 a tongue in cheek quip, or is there a Ref 180 prototype out there? If true, I can't wait for it to come out for all the reasons Taters says.

Pinkus is touting the much believed (but I believe undeserved) criticsm of Audio Research of churning product much quicker than the competition and that the company is marketing driven rather than customer-driven. If one analyzes objectively the product cycles at ARC, you will see new product intros in 3-5 year cycles (with an average of 4 years in between models). I do not think this is much different than most of the competition. Furthermore, having been an ARC owner now for some 7 years or so, I believe that each move up within the product line and from an older model to a newer model has yielded performance improvements consistent with the price differentials. But there will always be haters and that's fine, just not very useful in terms of their contributions to threads such as this where folks are trying to make informed purchase decisions.

As a long-time owner of the Ref 110, powering Maggie 3.6R's, the 150 should be plenty of power for just about anything. I loved the 110 - it was solid, bloomy, no-nonsense, and built like a tank. A beautiful piece of audio work.

@Pinkus -- is your reference (pun) to the Ref 180 a tongue in cheek quip, or is there a Ref 180 prototype out there? If true, I can't wait for it to come out for all the reasons Taters says.

I hope they do come out with a new amp soon. That way I can buy a ref150 at 50% off. As soon as the Ref150 came out you could buy a Ref110 for 50% off.

I don't know how it sounds compared to the Ref 110, but I can assure you that the Ref 180 betters the Ref 150 in all ways, and it should be available in a few years. You might want to wait.

Very much I believe. I had listened to the Ref 210 with about 787 joules years back and can say without qualification that the Ref 150 sounds, feels and was in all areas of perception much more powerful than the Ref 210. It drives the Sashas very well. Overcomes the low impedance and punishing phase angle such that I don't detect it as an issue. I heard the D'agostino stereo amp in my system in a head on contest against the Ref 150 for a few days and listened carefully to the differences all around but especially around 80-100k. The Ref 150 held its own with only minimal tube-induced slack in this area. But that was attributable more to the sound of tubes vs solid state than any lack of power. BTW, I loved the Dag and intend to eventually purchase it as a solid state alternative to the Ref 150. But it will not supplant the Ref 150 which remains my fav amp under 30k that I have ever heard. The Ref 110 was not in the top 5 in that category even though I appreciated its synergy in an all ARC system.
Just do it.

Thanks Gpgr... Seems like many owner comments are lining up very positively. I would still be grateful for any more comments, especially about whether the REF 150 will have the muscle to handle torturous low frequency capacitive phase angles and roller coaster impedance curves. Is the 1000 joule power supply a relevant consideration?

Thanks again,

Bruce

Birwynne
As one who had the Ref110 for a few years in 6550 form and then in KT120 form and then the Ref 150 since its initial launch, my opinion is that the 110 was a very good amp but a little too diaphanous--not very strong in the midbass and lacking a bit in "flesh on the bones" imaging. The Ref 150 is a significant and important upgrade in many respects. But most of all, it banishes the above weaknesses of the 110. The difference is more than a matter of degree. The Ref 150 is a great amp and I believe will go down as a classic in the ARC line. The Ref 250 gives a little better grip on the bottom and slightly better dimensionality, but the differences between the 150 and 110 are much greater than the differences between the 150 and 250. A trade up from the VS-115 is an easy call and one that you would never regret.

@ David - thanks for your detailed report. I'm currently driving a pair of Paradigm Sig 8s (v3) with the VS-115 (w/ KT-120 power tubes). As mentioned, my pre is the Ref 5 SE, but it's still in its break in phase. Chris Osanna, the ARC tech manager, said it will take about 300 hours for upgraded Ref 5s to break in and I have a ways to go.

However, early reactions on the SE version are positive, but as Mitch said, I'm hanging in there. I'll come back later with a more detailed review after full break in. All I'll say at this point is there is a noticeable difference - more transparent, better imaging and definitely better low end timing and transient response. But, I'll be back in another 250 hours with more reactions.

As far as the Ref 150 is concerned, I appreciate member feedback especialy since the Ref 150 has been on the market for some time now and folks should be able to express more reliable impressions. So as I said above, I would be grateful to read more feedback.

The Ref 75 is obviously less expensive than the Ref 150. However, if and when I upgrade, I think I'll probably opt for the Ref 150. The S8s have some pretty rough capacitive phase angles and impedance curves in the low end. So I think the 1000 joule power supply in the Ref 150 may come in handy.

Of course, if the EE techie members think I'm mixing and matching apples and oranges with respect to power supply headroom stats and low end phase angles and impedance curves, clarification would be welcome. As an fyi, I supplement the super low end (50 Hz and below) with a sub woofer, so my impression is that I'm rockin' ok.

Thanks again guys.

In the Reference 150 Video taken at Seattle's Definitive Audio, ARC sales Rep. Dave Gordon remarks, "We don't introduce new products that often."

You're kidding, right?

"we use Wilson (speakers) throughout the factory." a very enlightening statement for me.

I went to a small UK show, run by one company 2 weeks ago and it was one of the best I have been to. It even had Dan D'Agostini talking about his momentum monoblocks.

To get to the point, 2 of the 4 rooms had ARC amps, both the reference 150 and 75, on different speakers, but next door to each other. The first room had Wilson Sophias I think, initially with a Krell amp, ouch. Harsh, edgy sound. Then a reference 150 was put in instead, a collective Aaah..., from the audience. Just a lovely detailed but smooth sound, big soundstage. No loss of detail compared with the Krell, but a really musical, not etched "HiFi" sound.

Moving on to the Ref 75's, with Vertere speakers I think, a very similar sound, all the charectaristics I like. The store owner, Trevor, who I know quite well, said he has a number of customers changing from Ref 110 to Ref 75's, if that helps with the question of Ref 150 against ref110's.

My impression, for what it is worth, if your speakers are sensitive enough, the Ref 75's may be the sweetspot in the range. A review by a long time ARC fan in HiFi News a UK mag, suggested just that. He opined that for Tube amps, an output of about 75watts was optimal, with so many great amps, including ARC ones, at that level. I am sorely tempted by the 75's, when I can get the cash together.

Finally the room with the Momentum amps was in a different league, with larger Wilson speakers, I can't forget the model I'm afraid. With the new Momentum Pre, I don't think I have heard a better sound, ever. Mind you they are in a different price league too.

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Bif, give it time and hang in there until it fully breaks in. I'm sure the upgrade is going to separate itself from the standard Ref5 and your upgrade investment will be well worth the money spent.
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I would appreciate kick starting this OP again. Looking for more current comments. Just upgraded my Ref 5 to the SE. Initial impressions are quite positive, but the upgrade still needs more time to complete break-in. That's why I'm asking about the Ref 150. Wondering how much improvement I'll realize going from the VS-115 to the Ref 150. Kinda thinking that the law of diminishing returns will be kicking in.

Can you display your graphics on clxs with ref150? We tried the clxs in 16ohm taps and works excellent !!!
But this will make less power from the 150

Has anyone compared the REF150 to REF250?

In my brother's set-up driving the Sasha with full ARC (CD8, REF5), the REF150 sounded great. Buying the whole system at one go during the 110>150 transitional period, the local importer agreed to first lent him a demo REF110 (6550), and subsequently replaced it with the later KT120s equipped unit while awaiting arrival of his then to be released REF150--hence the observation in my first post above.

Curious as to whether the REF250--despite similarities--is significantly better, or close enough a call with just power difference. There were 3 sets recently at the dealer but were pre-ordered units and were sent off immediately to their respective owners so no chance as yet to audition one.

Also, if any experience on how these new generation ARCs compare to the like of LAMMs, VTLs and VACs--impressions preferably from owners or first hand experience in home/store demos. Thanks.

You can turn the fans down. There is a 4 way fan speed switch inside. Factory setting is maximum speed, but if you do not plan to put your amp in a cabinet of some kind, you can safely turn it down to minimum speed, or disconnect it altogether (that is how I used to run my Ref110).

Comparing the Ref110 vs Ref150, the new amp has double the energy starage (24x 470uf/450v caps in Ref150 vs 12 x 470uf/450v caps in Ref110), different coupling caps (may be the same as those used in Ref 40 - but not sure) and KT120 tubes.

I haven't had a chance to hear the Ref110 vs Ref150 side by side, since my Ref110 is long gone, but I think that the Ref150 has better bass (although still not state of the art in solid state terms), more clarity and resolution on top. It is increadibly dynamic, and retains one tf the Ref110 halmarks - excellent PRaT and midrange texture.

Overall, I still prefered my Dart, but the sound quality difference was nowhere near as big as the price difference may sugggest ($30.000 vs $12.000). If I hadn't had the dart, I might have bought the Ref 150.

Just spent a couple full days using a demo 150 with my Martin Logan CLX full range electrostatics. Even though the MLs have a tough impedance that drops to an ohm at high frequencies, the best sounding tap by a large margin was the 16 ohm connection. The sound was very good and reasonably smooth.

Using a computer based RTA, i noticed that the response tilted downward as I moved the taps to the lower connections and sounded progressively better on the highest tap value. (not so good on the lower values)

Very rich and dynamic sounding. The fans are quiet but are audible when anywhere near the amplifier. The dynamics were very good and the amp was quiet even compared to a rock solid Class A Accuphase.

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Flex2: I to have owned all of the AR Reference preamps except the Ref5 and anniversary model. Each one was excellent. But to my ears, each new incarnation was better. Pretty much, it comes down to a matter of preference.
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Does anyone have a REF150 ?
Can some owners comment on the sonic attributes of this amp and also what other amp did it replace in your system. REF110, VTM200, VT200, VS115, or others.....

Considering replacing my Classic 120's with a REF150.

Any feedback appreciated.

Oregonpapa:
New ARC products are always announced as a more or less big revolution in sound quality compared to the replaced model.
The truth is that many still prefer earlier models.
Personally I have used all Reference preamps except Ref5 and the 40 anniversary top model.
Still prefer Ref One...

Ref 150 might be extremely good, but value a ARC employee opinion for what it is. A coloured opinion.

I called arc on an unrelated topic and spoke with one of the techs and he said that the
Ref 150 driving the new Maggie 3.7s is simply amazing.
The REF 150 is on my Xmas list if business improves by then. :)

I have some of those coupling caps in the 1 mfd range if anyone is interested. They are ahem...quite large. Let me know.

I may have missed this if it was already posted, but the REF 150 also incorporates the same type of capacitors used in the REF Anniversary preamp. The transformers are upgraded, the caps, and the KT120's are, I believe the major differences. My understanding is that it has about the same energy storage, about 1,000 joules, as a single 610T. I should mention that I'm a dealer but I haven't heard one yet. I'm also a passionate music listener and I'm anxious to hear one.

The REF 250 introduced at CAS. The best tubed amp on earth?????

Considering replacing my beloved GNSC modded Classic 120's with the REF 150.

the ref 150 sounds better than about any ARC amp they have ever made, considering it has enough power for you. It is NOT just a tweaked ref110. go listen to it if you can, I was very impressed , I own Rogue m180s by the way.....

Anybody else compare the Ref 110 (both with 6550 and KT120 tubes) with the new Ref 150? If yes, can you comment on sonic differences and whether the extra $s to upgrade from the Ref 110 is worth it? Thx

Very well designed amp. Well behaved. Put out about 148W across 8 ohms. Single channel driven.

I went to my local salon to hear two amp's I'm been fixating over when low and behold , there was the ARC Ref150 plunked between them in the sound room . I don't no how those three amps would sound at home or over longer periods , but that day with that equipment , ( ARC CD8 , ARC REF 5 pre , Mag 3.7's ) the 150 breathed more like music than the other two more pricy amps . It effortlessly bounced the usually hard to drive panel's around the room . I'm sure system synergy played a large part the good guys at this salon are very capable .

"I have one in for service..Will keep you posted. Looks nice, huge coupling caps. This one is silver silver. Pretty. When it's finished I will report the power output and -3dB points"
Looking forward to your comments

I have one in for service..Will keep you posted. Looks nice, huge coupling caps. This one is silver silver. Pretty. When it's finished I will report the power output and -3dB points

"It looks like it's about time for all of the reference series amps from ARC to be replaced by a new model if they keep to their 5-6 year new model intro as they have in the past"
New 250s and 750s will be released soon.

LOL I can't keep track of all the ARC Amps. I'm sure the Ref150 will use KT-120's. Check with the factory on the KT-120 Ref 110 issue just to make sure it will work. I'm sure it will just a good idea to check with the factory first. Kalvin should know. If your in L.A. I can set it up and test it for you etc.

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It looks like it's about time for all of the reference series amps from ARC to be replaced by a new model if they keep to their 5-6 year new model intro as they have in the past.
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If i understand this, the REF150 is the REF110 replacement and the 110 will be discontinued correct?

I wonder if the REF 150 has enough power for the Maggie 3.7 or if the coming REF 250s are needed, what are your thoughts?

$12.995
Ref150 video