Audio Research Amp Shootout

Over Labor Day weekend a few friends gathered to do something we have discussed for quite some time—do a comparison of several Audio Research amplifiers. This was partly inspired by prior upgrades where two of the amps were compared and partly by rivalry (tube vs. solid state, switching vs. analogue, older vs. newer, etc.) Ultimately, we compared the 150.2 (Tripath switching amp), 100.2 (solid state 100wpc), SD135 (solid state 130wpc) and VS110 (110wpc tube). Since we wanted to have some fun with it we didn’t adhere to a rigid formula, we simply picked out specific tracks from 5 CD’s of various genres (rock, jazz, classical) and then rotated the amps into the system, comparing one against another until we all felt that we got a good sense of each amps unique properties. At the end of the day we were, surprisingly, pretty much in agreement on how each amp sounded and, to a lesser degree, how we would rank the amps in terms of preference. What follows is my own assessment of each of these products and, where necessary, observations of others who did not share my perspective. BTW, I have at some point owned all three of these solid-state amps but never a tube amp from ARC or anyone else.

I guess the first thing to point out is that, to a large degree, ARC has managed to craft a “house sound” that is pretty consistent among it’s varying designs. There were not enormous differences between these amps. I suspect that rotating in an amp from Krell or a low power tube amp would have produced a much greater contrast. The other thing worth mentioning, perhaps, is the associated equipment and room, which can be seen on my system profile if you care to look. Since the amp-speaker interface is crucial in determining how each amp will perform, it is probably worth noting that the Daedalus DA-1.1’s are 97db efficient with a fairly stable impedance of 6ohms. With this said, on to the comparison….

We all generally concurred that the 150.2, while a very capable and practical, was not up to the sonic standards of any of the other amps. The bass was somewhat rounded by comparison (only the VS110 was similar in this regard, though more tuneful and lifelike than the 150.2) and, more importantly, the sound was less three dimensional and organic. In addition, the midrange had a slight hardness or glare, particularly when pressed, that made this amp less natural sounding than the others and least like what you would expect from ARC through this frequency range. I owned the 150.2 for quite a while (it replaced a 100.2) and liked the amp when paired with my Harbeth Compact 7’s. But with a larger and more revealing speaker, I don’t feel this is the best choice in the ARC lineup. It does run very cool and uses almost no power so I would give it great marks for being “green” and it will probably last a lifetime as well.

Most of us were eager to hear the venerable 100.2 against the new SD135. Here the comparison was much closer, with the SD135 offering slightly better inner detail, warmth, refinement and slam. The 100.2 was a little more brightly lit on top, with greater sparkle to the highs. The SD135 is ever so slightly darker hued than the 100.2. For wine lovers an apt comparison would be the 100.2 representing a good, young California cabernet while the SD135 and excellent French Bordeaux. The 100.2 was a little less sophisticated and brash, the SD135 more subtle and nuanced. All but one of us preferred the SD135, some by a large margin, myself less so. The SD135 is also a bit more user friendly and appears better built. The on-off switch is more substantial and the on sequence reliably comforting. It is also more substantially constructed under the hood. Overall, both of these are very fine solid state performers and it became clear through this comparison that the 100.2 deserves much of it’s cult like status among ARC amplifiers. But the SD135 was, for all but one of us (the owner dare I say?) the better product overall. It sounded more realistic, dynamic, dimensional and authoritative and was sounded better than the other amps in the shootout on all types of music.

Equally intriguing was the comparison of the tubed VS110 with the other solid state amps. The VS110 possessed greater dimensionality and was more engaging through the midband—realistic textures and more subtle inflections and variations of voice and instruments could be heard. But it did not have the speed, dynamics or ability to project sound as well as either the 100.2 or SD135. The VS110 was a joy to listen to—it spent more time in the system at the end of the day—and captured a bit more of the emotional content of each recording, though the SD135 was very close in this regard.

Again, these are mostly my impressions based on my room and system. Your mileage may of course vary. But it was a really interesting exercise that I thought may be of some benefit to those looking at any of these amps for their system. I know this posting is short on details—I’ve been trying to find time to finish this write-up for weeks—so if you have any questions please feel free to post them and I’ll try to respond to specific areas of interest. Happy listening!

Thanks for the excellent review! I'm sure you guys had a blast listening to all the ARC amps. I concure with your findings on the SD135. I have listened to this amp as well as the VS110.

I have also had the pleasure of listening to the ARC HD220...WOW! You really need to hear this amp. One of the best amps I have ever heard. It combines the power and muscle and control of the SD135 with the seduction of the VS110. Best of both worlds...
First of all lets look at the problem I see with your amp shootout to start with: you're comparing different amps in design as well as price. Should it be an epiphany to you that the SD-135($5000) and the VS-110($4500) would sound better than the 150.2 ($3000)? (after that what's to compare?) ARC would be foolish at best to sell a $3000 amp that sounded as good or better than their $4500 & $5000 amps! Not to mention that one is a digital design, the other a tube design and finally the others analog solidstate designs.
The designs alone would produce minimally a different sound whether it be better or worse.(preference would come in somewhere I think) So...
Never mind the nay sayers this is a great exercise,makes for good reading and should happen more often with those fortunate enough to be able to do a shoot out.Kinda like a wine tasting.
Audio Research gear is one of my all time favorites. Not just excellent sounding components but built to military specs and is definately eye candy! It isn't too often that you can read a comparison review of all the above components in one post, found it interesting & informative and we thankyou sir! The one piece I have not heard is the 150.2 but never felt the urge to try it because of its Tripath design. I'm sure there are very good sounding switching amps but have always prefered the more conventional designs.
Great report. It is always fun to do such comparisons and identify the various strengths/weaknesses and maybe find one heck of a good value in the group.

As for comparing amps of various prices, the higher price models do not guarantee a higher listener "score". Prices often reflect marketing "strategies" and have little to do with cost of manufacturing, sophistication of design, nor resulting performance. I had a VT130 that was far far superior to the Classic 150s that I also owned. And the CL150s were nearly double the price.
Great review and test. I enjoyed the scenario and evaluation. Hopefully, others will do similar test. No scientific evaluation changing cables for each amp and such. A straight amp vs amp comparison. This is more real. When I was considering upgrading? from my AR SP11 to another pre-amp with remote control. (I felt lazy one day and considered this). I evaluated an SP 16, which was not even in the ball park. An SP17, not close and a REF 3. The REF 3 was first compared with the top of the line Boulder pre-amp and was actually very close. Taken home against my SP 11 the differences were not drastic. Especially after replacing my SP11 tubes with new. However, I found myself listening for longer periods of time to the REF 3 and really enjoying myself. No swaping of cables, just swap the pre-amp and play the music. I love good music and I found that many of my older CDs actually were recorded poorly and the REF 3 revealed that although the music was good, many recordings suck.

First of all, there is "no problem" at all with your amp shootout. For ARC fans this is exactly the kind of comparisons we are interested in. I own a 100.2 and have been curious about the other models (tubed and SS) that have come along in the ARC lineup over the past few years. It is unlikely many of us will have the opportunity collect and listen to these amps side by side. I appreciate your willingness to share your observations with us.
Oh man.. loved the shootout! This is great stuff..the kind of thread that can evolve. I have owned two ARC 100.2's. The first time I let it go I was chasing my own tail trying to "get back home" to that beautiful midrange rendering--a touch of velvety texture, but uncanny 'tubelike' transparency that this amp is capable of (bass, treble all there, all great too). I have had, also 2X, ARC Vt100MKII's and 1x Pass X250.5, and a Plinius SA102. All played, over time through dyn s3.4s. Various cd players, dacs, preamps, cables...etc. Long story-- the 100.2 and S3.4 are with me today. There is something to me 'just right' with the sound when this amp is running the show. I would like to hear the 135 though and if the future is good enough to me, perhaps the hd220 will be in it. To me, the 100.2 gets it so right in the midband, I can live with whatever shortcomings at the other ends (very slight btw-- I would say the Pass X250.5 had a top end that was superior in its clarity and extension, it sounded so vivid on top the you could hear the burnished tone of high hats and the like). The 100.2 comes very close. To my ears the mids come across as more real with the 100.2 and the bass performance seems a bit bigger, perhaps rounder but not as accurate as the X250.5. I remain amazed at how cleanly and loudly the 100.2 can drive the current hungry s3.4s, as well as develop a biG soundstage. The Plinius Sa102, to my ears, was actually kind of a dissapointment. After the Pass (full bodied cali big red, perhaps a bit on the dry side) and the Arc (hmm perhaps a '98 Amarone della Valpolicella), the sa102 just seemed uninvolving and a bit too polite (a merlot, pick one I don't like them). I know others have had great success with this amp and I wanted to love it (looks alone it is sick--in a good way) but it just did not do it for me. The vt100 mkii's-- incredible life like midrange, easy as warm apple pie to listen to, but not enough steam for my tastes (draining bottle too fast, but o the taste!), and the downtime and constant tweaking (i'm an EE too and total electronics geek) sent these guys packing (i bet with 8 ohm speakers like Spendor's one could get close to musical nirvana). Sorry for the long winded tangents, but I love a good Audio Research discussion--and a good red.

Dodgealum...thx for sharing your impressions on the ARC amp comparison. I own the Ref 110 and love it (it's in an all ARC setup driving Thiel 2.4s) and concur with your description of the general ARC sound. I started another thread on a new SS integrated coming from ARC at the $6K price point ( While it is still being demoed at ARC's dealers (so it is not officially launched as of yet), I am intrigued by this new 200w/ch SS integrated (that can also be used as a power amp only). Keep a look out for this new ARC entry. I am sure it will prove to be another winner from the folks at ARC. Thanks again for a great comparison.
Glad to see some folks are interested in the results of our comparison. At first I wasn't sure if all the swapping in and out was going to be worth all the time and effort involved, but as the day wore on we really got into it--I think mostly because you tend to find a lot of speculation on the web rather than head to head comparisons like this one, which, though not without its flaws, is at least a bit more scientific than choosing equipment by reading reviews or following the web chatter. Many times we end up trying to piece together how something will sound in our system based on a variety of inputs--a review here, someone trading up there, a show report or blog, etc. It is rare, I think, to have a chance to do a straight ahead comparison of several products without anything else in the signal chain (let alone the room) being altered. Anyway, it was a long day but really enlightening as well. I understand the concern about the retail price differences between these amps and had thought to put those figures in the review but forgot in my haste to get the review posted. Though I suspect that most people reading the thread will know or quickly be able to find out what each amp sold for when new. Besides, I agree with Jafox, sometimes leaving price aside allows you to assess products completely on their merits and often times you can be surprised by a budget performer that can play with higher priced gear. One other thing I forgot to mention was the inclusion of a McCormack DNA-500 in the mix. This amp came over late in the day after we had run through the entire ARC lineup and we did not have time to go back and compare the DNA-500 to all the other amps lying about--only the SD135 was put head to head. It was universally agreed that the DNA-500 sounded quite good in the system--very authoritative yet smooth and refined. The SD135 was very, very close in performance, giving up a some slam in the bass and extension in the highs. Nearly all of us agreed that the SD135 was more refined and realistic through the midband, allowing more detail to emerge in a more layered three dimensional space. The DNA-500 sounded like the 100.2 on steriods--a bit bolder and more colorful than the SD135 but not as subtle in its presentation. I think if your speakers require gobs of power the DNA-500 would be the better amp. In my system, with highly efficient speakers and a fairly stable load, the SD135 was the better amp--all but one of us concurred in this view. It was just a bit more lucid in through the mids and that really brought out the essential musicality in every recording in a way the DNA-500 did not.
How-bout a 90's Threshold T-200 against one of those nice ARC amps -like the 100.2 maybe?... or what ever?
Will the SD 135 be reviewed by any of the hi-fi magazines?

I dunno---it seems to have fallen into the same black hole as the 100.2 which, to my knowledge, was never reviewed in the mainstream press. This is one of the reasons we decided to do a shootout and spent so much time that day comparing the 100.2 with the SD135. At least the post gives you some idea of how each amp performs.

Have you had any experiences with the VS115 or BAT? I'm considering going back to tubes for my Vandersteen 2 Ce Sig II and ran across your review and will now put the SD135 on my list as well.
Would you recommend the VS110 for Vandersteen 2 CE Sig II? thinking on bidding on one here on Audiogon.
I see why Eee3 had negative comments about this write up, he owns a 150.2 which did not fair well in the shoot out.
Sorry guys, I haven't heard the VS115 or anything from BAT. Also cannot comment on the VS110 with the Vandy Sigs. I will say that based on my experience with the Vandy 2's and 3's I suspect the SD135 would be a better match than the VS110. The Vandy's lean to the warm side and could use some control on the bottom end. If I had the Quattros I might prefer the VS110 instead, since the built in sub and tunable bass would free you up to go for more texture and dimensionality in the mids and highs.
Ajackson1, me having a 150.2 has nothing to do with my comments about the shootout. If you read my comments carefully, you would have understood what I was trying to convey ie; again, the comparison was done with amps of different designs and different price ranges from the same manufacturer!! That is not a shootout! A shootout is comparing amps in the same price range of similar design and from different manufacturers. That's how you gain a broad perspective of components.
Again, how is it a revelation to anyone that a $5000 amp sounded better than a $3000 amp from the same company!
Would it make good business sense for a company to do that?
I think not. Companies sell a range of components in different price ranges that follow an upgrade path.
ARC does it very well, their components sound progressively better as you move up in the line, as it should be.
Also, just for your information, I'm very happy with my 150.2!! I know what it it capable of an I don't expect it to do anything past that!
Finally, you obviously have seen that I have an all ARC system, duh! So, obviously I like ARC equipment!!!! In fact I've been using ARC equipment for 25yrs. I know the product very well, probably better than most folks who responded to this so called shootout. So, don't try to imply that I somehow have something against the product other than what I've articulated.

Thanks for the advice, I'll have to line up an audition soon!
Eee3...your points are valid but I think you may be reading a little bit too much into the term "shootout." I also run an all ARC system and I found this comparison very useful because it just reinforces that there is an ARC 'house' sound that ties most of their products, with a slight difference in voicing among those products or a clear difference in intended application. As you clearly state there are different price points that ARC is building to across the SS and tube design paths and those price points increase as power and intended functionality increases. But what is useful in this "comparison" for those who might not be familiar with ARC products or for those who are shopping for one is the description of the common sound across the products and where the "flavor" or "nuance" varies across them. For that, I commend Dodgealum and his friends for sitting through this exercise and sharing their thoughts with the Agon community. I, at least, did not read anything more into this comparative study than what it was. Your points are certainly valid but this exercise was useful nonetheless. My 2cents worth.
I don't think you have a copyright on the definition of the term "shootout". I have often wished that I could conduct a side by side listening comparison of all the amps he included. Regardless of price, as an ARC owner and fan these are all amps I have or would consider purchasing and I found his observations interesting and helpful. I cannot think of a term that would, with complete and total accuracy, describe the listening event/comparison he did. Until a better term comes along, shootout seems just fine.
I also have the 100.2. it is a wonderful amp.
I could not help noticing that in this thread, the 100.2 fans happen to own lean-sounding speakers: Triangle, Dynaudio and Merlin TSM with no BAM module.
Amps base on Tripath technology must implement a 12 db/octave treble cut filter at the output, to filter the internally-generated ultrasonic noise. The filter is at 100 KHz, so it rotates treble phase (slows down high-frequency response) down to 10 KHz (one decade below the filter frequency), smack in the middle of the human hearing range.
Maybe our fellow poster's preferences are justified by sinergy: slightly lean/bright speakers with a slightly veiled/filtered amplifier.
No criticism, I like ARC amps, have owned a couple and currently use mellow-sounding tube comment is just food for thought.
Enjoy the music
I think it was a good comparison and Dodgealum was lucky to able to "compare" different models of ARC amps. Not many get that opportunity have buddies that live close by and to be able to do this. Good post :)
Casouza, The 100.2 is not a Tripath amp. The 150.2 is a Tripath amp and it does sound much different then the 100.2. The 100.2 is the best I've heard anywhere near it price. It's a real sleeper of an amp. I was shocked when I heard it.

Not a fan of the 150.2 at all.
I appreciate the time and effort you spent to run these amps and provide your impressions. I'm not sure I necessarily agree with Eee3 that going up the price point ladder means better sound, it does generally mean more power and with speakers that need that power, they will perform better, but in my experience the lower powered versions of a company's basic design generally sound better than the higher powered version if it is enough power to drive the speakers. I'm not an engineer, but it seems that lower power versions are less complex and that leads to better sound. I also don't see what the argument is that comparing different circuit desing approaches with the ARC line is somehow not a "shootout" - I found that aspect of the comparisons extremely interesting, especially if I want an ARC piece and was a bit confused by the difference in design. I would like to see more comparison like this. 4-5 pieces as the only variable, and some comments from the group on their observations and preferences. The system context, room, etc are critical elements too, I can tell you that if the speaker were the Merlin VSM, the VS110 would likely have come out on top here. Thanks for your efforts.
Actually, I use my mc275 with the Merlins. I used the 100.2 with B&W Matrix 805's. I just got the Merlins.
Yup, some speakers need SS to sound their best, and some simply work better with tubes. The Ars Sonum intregrated would be a great match with your Merlins if you are ever looking to try a different combination. I'm not sure why, but the EL34 tube just seems to work ideally with the Merlins, maybe because it is such an easy speaker to drive that it doesn't need the extra grunt of 6550/KT88s, or the current and damping provided by SS. But, this is probably best for another thread. It would be ggod to have a section for shootouts, I love that type of discussion and comparison.

What will I gain in terms of sound quality and performance by switching from Belles 150A Ref amp and Belles 21A tube pre to ARC SD 135 and LS17?

I would be surprised if anyone has actually ever done that comparison, especially with your speakers. That Belles combo sounds like a pretty good one. I would be surprised if it was a major, clear cut improvement - your gear is pretty good.
Enjoyed reading about your shootout between models. Sounds like you and your friends had a great weekend. If you can get your hands on a Ref 3 and a Ref 110 I think you'll be mighty impressed. You'll love the synergy with the Esoteric and the VPI, especially if you upgrade to the Dynavector XX2.

Great write up! Sounds like you and your buds had a great weekend. If you ever get the opportunity to do something like that again, try the ARC Ref 3 or 5 / REF 110 combo., I think you'll be very impressed. When I bought my gear, I also listened to the ARC HD 220 solid state...very impressive, with plenty of slam,but, the Ref 110 also has plenty of slam, is very neutral for a tube amp, revealed amazing detail, texture, bloom, soundstage etc.... The Ref. 3 was the icing on the cake. It really made a huge difference in my system. In your quest for a great sound, they're worth auditioning and would definitely sound outstanding with your Esoteric and VPI / Whest combo.
I actually like the sound of the MC275 and the Merlins together. I am in no hurry to change anything. it is very easy to enjoy. The 100.2 sounds very good with them also.
I've had the ARC SS amps on my short list of amps I would like to try in my system in that I have been most pleased with the sp16 pre-amp, so this was very interesting to me. Thanks!
the 100.2 is amazing!!!

Looks like the ARC 100.2 greats the door prize.  If it is 100 RMS, that may not be enough power for my upgrade plans.  However, I will have to check out a few reviews, and see if is still worth the money for its sound quality.  I am unaware how old it is.  Though, I am familiar with ARC reputation, buying any vintage amp over 15 years old is a potential invitation for buyer's remorse.  I can deal with that at my age. Odyssey's Khartago Plus might be superior to this ARC vintage unit, or even the much touted Parasound A-21 which has double the power of 100.2. Many people lover the Parasound amp, and less people dislike it  However, this type of ration is not a vindication of its superior performance or sound quality

I realize this thread has been dormant for 6 years, but it mentioned about the 150.2   which I less inclined to  buy because of some of the comments of its detractors

Very interesting comparison, but just a suggestion Dodgealum, as a Daedalus user, if you can get a listen to the ARC Ref 75SE, it is a really special Power amp. I actually preferred it to the Ref 110 and Ref 150. The 75 watts is more than enough for Daedalus speakers, I use the DA-RMas myself. I know it is twice the cost of the amps you compared, but it's worth it.

 I have never been so keen on the ARC Pre's, as the Power amps and I found the Modwright 36.5 was a great match with the Ref 75.