McGary Audio SA2 Power Amplifier | REVIEW

When I first set eyes on the attractive McGary Audio SA2 vacuum tube amplifier, the first thought that entered my head was “stingray.” Anyone who has observed this sea creature will know immediately what I mean: just one look at that front panel tells the story. Anyway, I can’t use that moniker, as it’s been assigned already to Manley Laboratories’ iconic product of the same name.

When I was a kid, I greatly enjoyed watching a particular type of ray termed the cownose ray for the obvious protuberance on its front portion. These rays frequented the waters around the house where I grew up and were great fun to watch, chase, and attempt to capture. Of course, we were never successful at the latter.

Popping off the diamond-shaped thingy (really a cover) on the front panel of the SA2 exposes a pair of RCA jacks for single-ended input of signal. There! I had it… now the front panel looked much like the profile of my favorite cownose ray! Even better, the McGary Audio SA2 takes on the appearance of a friendly ray, complete with winking eyes in the form of magic eye tubes positioned on each “wing.” More about these later.

OK then. If I get cheeky, “cownose ray” it is.

Back story…

The $7985 McGary SA2 is actually the second product from audio entrepreneur Mike McGary that I have reviewed. Regular readers might remember my assessment here at PTA of an earlier McGary design, the SA1. That model got a rave from me, and plenty of other reviewers have commented favorably on it too, particularly in show reports. Well, Mike McGary is back, and this time with a bigger, better, and more expensive design, the aforementioned SA2. While the SA1 was more of a budget-minded and straightforward design, the SA2 is all about powerful versatility.

First, about that power. The original SA1 is good for 30 watts per side, whereas the SA2 more than doubles that output at 80 watts per channel. This power output is accomplished using high-output KT-88, KT-90, or KT-120 power tubes as opposed to the EL-34 tubes used by its littler (but older) brother. I’m sure the far heftier transformers utilized by the SA2 help as well.

I’d also mentioned versatility, and this may well be the best aspect of the SA2 for many music lovers. First, the user has choice of inputs via both RCA (unbalanced) on the front panel and XLR (balanced) on the rear. A switch on the amp’s top panel allows quick selection between the inputs. Another nice feature is on-the-fly choice between triode and ultralinear modes, again switch-selectable. Want more? There’s even user-adjustable global negative feedback which can be dialed in using a cool-looking retro knob mounted up top. Topping it all off, one has control over the brightness of the magic-eye tubes and choice of 4, 8 and 16-ohm taps from the output transformer.

Back to those nifty magic-eye tubes. From a visual standpoint, these things are super cool, with one per channel, winking away at me from the front panel. As expected, these devices give the listener a real-time visual representation of the amp’s output: as the “pupil” gets smaller, the power output gets larger. If the “pupil” collapses into itself and disappears, the amp is clipping. For the record, I never got anywhere near clipping with the SA2 driving my ATC SCM 100 monitor speakers, even at ridiculous volume levels (for me…). If you do need more power, rest assured that the SA2 can be bridged for mono output; buy two and you’re in business.

Oh, and like the SA1, the tubes on the SA2 are all self-biasing. I”m sure some audio geeks enjoy the process of tube biasing (actually, I don’t mind it…), but for most of us, it’s one less thing to have to worry about.

Fit, finish, and overall build quality are impeccable, as I would expect from a product hand-built by a talented engineer such as Mike McGary, and the SA2 comes with that wonderful McGary Audio lifetime warrantee. You buy one of these things, and you are in good hands, folks.


The majority of my evaluation of the McGary SA2 was done using a very simple, straightforward system. All digital, the bits were transported from my Mac Mini via USB to my Bricasti M1 SE DAC. From there, the analog output was fed directly into the balanced inputs of the McGary amp, which in turn drove my rather large ATC SCM 100 passive studio monitors. Volume control was achieved directly using the attenuator on the Bricasti DAC.

Listening Impressions

I love flaunting general audio perceptions. It’s part of what my editor calls “geeking out” with my gear. Maybe it’s the scientist in me–never leave unexplored any possible options, even if consensus among audio experts says they probably shouldn’t work. Or, put a bit differently, you never know what might happen (barring, of course, something exploding or burning to a cinder) until you try.

One such perception I love to test is the “general knowledge” that ATC speakers need a lot of power to open up and sound good. I have found that listening at the sound pressure levels which I enjoy, my big ATCs do just fine with amps such as the ten-watt-per-channel LTA ZOTL 10 and any of Nelson Pass’s First Watt creations that I’ve tried. OK, if you aim to fill a concert hall with an excess of 100 dB of clean and undistorted sound, your mileage may vary.

Another axiom regarding ATC speakers is that they need solid-state power to really rock. Indeed, this is what most folks use, including myself. I’ve read accounts of audiophiles getting good results coupling vacuum tube power with ATC passive monitors, and I’ve been game for a while now to get a big tube amp behind my SCM 100s. If I recall correctly, the McGary SA1 was no slouch with these speakers.

How, then, would the twice-as-gutsy SA2 account for itself driving these same monitors? Chomping at the bit, I wanted nothing more than to find out for myself. My ATC SCM 100s are studio monitors. As such, these speakers are linear, dynamic, and extremely accurate. They are truthful, and I often find them to be pleasant listening companions. However, one term I wouldn’t use to describe them is “euphonic.” The ATCs are very good at letting me hear what is happening upstream component-wise, which also makes them very good reviewing tools.

However, like many serious listeners, I want to sometimes be wowed and lulled; sonically pampered, if you will. We often hedonistically enjoy hearing our music presented with lushness, bloom, and added dimensionality. While these attributes might be present via the ATCs when amplified by good solid-state, I’d say that they aren’t exactly emphasized. Dang it, sometimes I just want some emphasis!

Enter the McGary Audio SA2.

Generally speaking, the SA2 takes my old reliable ATC monitors to new and unending heights of musical enjoyment! They breathe life into the ATCs. There’s new presence and dimensionality added to an already on-point sonic footprint, and that’s sometimes a good thing.

Specific Impressions

With the ATC monitors propelled by their normal engine, the Pass Labs X250.8 amp, I get plenty of headroom, boom, and sizzle. I also get a good dose of refinement. Cruising with the Pass amp is like having a well-tuned supercharged V8 under the hood; you just get that feeling of unlimited but refined power at your fingertips. That’s what 250 watts per channel courtesy of Nelson Pass and associates gets you.

I was a bit concerned that 80 watts per channel of good vacuum tube power might not be enough to achieve the mountain peak. No worries: it turned out to be plenty. I recall Mike McGary beseeching me to push the SA1, which I did. The SA2, however, never really had to breathe hard. Those cat-eye tubes on the front panel just never did the full pupillary eclipse, no matter how hard I tried.

Now, on to the good stuff.

I never had any idea the SCM 100 monitors could sound this lush. I’m not talking about in a wading through syrup sort of way, but rather, the portrayal of tonal body to the musical note, be it from voice or instrument. I’ve been listening a lot lately to keyboardist Glenn Zaleski’s new album The Question (streamed via Qobuz, 24/96 flac). This guy has a real touch at the piano; his playing is expressive, yet precise. Via the McGary Audio SA2 and the ATC speakers, my system picks up every nuance, every inflection. In short, anything and everything worth hearing. Never is the sound overly etched or analytical, but rather what one should expect to hear from a well-mic’d piano at the hands of a jazz virtuoso.

Decay of notes in the ballad work is not only sublime in its ever-fading palpability, but also toothsome in its presence. Oh, and Zaleski’s side-men are pretty good too. Check out the artful trumpet on cuts such as Dave Brubeck’s “Strange Meadow Lark” and Zaleski’s own composition “Smoke and Mirrors.” On the latter, the instrument shifts from mournful to howling as it weaves its way in and out of competition with others in the band. The McGary amp helped keep me engaged and fascinated by the tonal texture of the musical genius happening here.

Another fun album of late is Italian jazz vocal interpreter Maria Pia DeVito’s Dreamers (streamed via Qobuz, 16/44.1 flac). Alternating between whimsical and beautiful, this compendium of standards features DeVito’s interpretations of jazz and pop standards. This is a beautiful recording that captures the lush elegance of Ms. DeVito’s floating voice. The tonal colors of the vocal inflections are captured superbly by the McGary/ATC combination. Vocal and instrumental pace and timing (which are both imperative to make a recording like this one work) are nailed here; this comes as no surprise with the ATC studio monitors (they are British, right?), but the effect only seems intensified with the aid of the McGary SA2 providing the power. Listen to the interaction between DeVito’s complex vocal inflections and the deft drum accompaniment on Bob Dylan’s “Simple Twist of Fate,” and you’ll see what I mean about getting the timing right. Let’s just say it works.

Modes of Play

I spent a fair bit of time comparing playback via ultralinear and triode modes on the McGary Audio SA2. An album like Dreamers is an excellent place to highlight some of the differences I heard. As expected, ultralinear provided me with a more powerful and gutsy presentation, with more emphasis on leading-edge attack and dynamics. Swinging back around to triode mode left me with a softer, “bloomier,” and Zen-like presentation of the music. As the power output is effectively halved, I noted also a considerable decrease in gain, so I had to adjust the volume upwards to compensate.

I also noted more activity from those magic eye tubes. I’m more of a detail guy, so I have to say that my personal preference with the ATC SCM 100 speakers was for the gutsier, more forward ultralinear choice. Your results may well vary, depending on personal preference, choice of ancillary gear, and program material.

Speaking of “bloomier,” if you want more of that, you can dial in some feedback. Again, really not my thing, but it’s nice that Mike McGary gives you option, and in a totally continuous fashion for those of you fine-tuning tweakers out there. Dialing in an extra dose of second-order harmonic distortion can do some cool things, or so they say.


I recently picked up a totally re-built set of Quad ESL-63 panels (thanks Scot!). I’ve never really been a “panel guy,” but with the heaps of praise rained down on the Quads, in whatever version, throughout the years, I figured it was time to give them a try. I’ve had a lot of fun messing around with these classic speakers, and I can indeed now appreciate what all of the fuss is about.

The biggest challenge has been finding a good amplifier to interface with these. I tried low power favorites (like the First Watt amps) and came away with the feeling that more power might be beneficial. The best fit I’ve had so far is the Rogue Audio Magnum integrated (thanks again, Scot!). The combination of tubes and around 100 watts per channel of power seems to really make those ESL-63s sing like they ought.

All of that got me to thinking that perhaps the McGary Audio SA2 might just be the perfect power source for my Quads. Power plus refinement–what’s not to like? Out went the ATCs and in went the Quads.

Of all the amps I’ve tried with the ESL63 speakers, the McGary Audio SA2 best highlighted the Quads’ ability to spotlight that all-important midrange magic coupled with sufficient power and dynamic touch. Female vocals were more forwardly and brilliantly presented than with the ATC speakers, and with even greater resolution. If anything, I heard almost too much of a good thing, finding that I preferred Maria Pia DeVito’s voice “tamed” a bit by listening in triode mode. With eyes closed in a dark room, the spatial characteristics of the Quad/McGary combo were almost eerily scary in its “reach out and touch the performers” illusion. All in all, a matchup well worth remembering.

Summing Up

Editors Choice AwardMy experiences with the cownose ray (the animal) have shown it to be a docile and beautiful creature, but one that must be respected also, as it can pack a nasty punch with that sting. While there’s nothing nasty at all going on with Mike McGary’s version of the “cownose,” it does remind me of the animal, and not just in appearances.

The McGary Audio SA2 is a beautiful creature too, both in its visual presentation and sonic demeanor. And it packs a big punch when the music calls for it. For anyone in the market for a more powerful vacuum tube amp, it’s a must-hear and a no-brainer.

I’m a big value guy, and it’s hard for me to say that anything costing $8000 is a good value. I loved the McGary SA1 at half the price; can I assign comparable value here? Mike McGary tells me that the thinks the SA2, even at twice the cost, represents an even better value than the SA1. After thinking on it, I have to say that I agree. Factoring in the extra power, bigger everything, and all that extra user versatility, the McGary Audio SA2 hits it out of the park. Oh, and don’t forget about that lifetime warranty.

For anyone shopping in the sub-$10,000 window for an amplifier, the McGary Audio SA2 is a must-audition product. OK, let’s make that sub $20,000. Highly recommended indeed.


  1. Hey John, I enjoyed this review tremendously. I didn’t quite get the sense if you preferred the X250.8 or the SA2 with your ATC’s. Is the SA2 able to control those monitors with authority and similar dynamics? Or do you give up some bass control and dynamics in exchange for that lush sound you described?

    I was also hoping you were able to post your impressions of the SA2 vs the 250.8 paired with the Fritz Carrera or the ATC SCM19 v2’s. I own the Fritz, which per you review sound similar to the SCM19’s so your impressions would be very helpful. Which amp do you feel would pair better with the Fritz? I hope you didn’t sell the SCM19 V2’s! Or did you? 🙂

  2. Mike is a very conscient and very clever Engineer ! He even has an acute listening ability !

  3. What a superbly informative review! The SA2 was one of the highlight of my visit to CAF last year, driving a huge pair of beautiful Tekton speakers.

    I have a somewhat off-topic question though for my system ( the wonderful ModWright KWH 225i driving custom Studio Electric M5 speakers similar to your ATCs): do you use any elastomeric material between the ATCs and the stands or between the stands and your floor? I have abandoned using any in my similar speaker setup and am curious.

    • Actually I don’t. There may be a very thin layer of rubberized material at the interface between the speaker and stand, but nothing at floor level. In fact, I don’t spike the stands, as I need to move the speakers often for review purposes, and they can slide easily over my wooden floor that way.

Comments are closed.