Welborne Labs 2A3 Moondog Monoblocks

Below you will find reviews of the Moondogs, all of which were carried out with the MagneQuest DS-025 output transformers besides the Positive Feedback review. Of particular interest to 2A3 lovers is the Joe Roberts article in Sound Practices. Joe does a great review of the Moondogs but also talks of 2A3 amps in general. Regardless, I think Joe Robert's is always a good read.

Listener Magazine
Peter Breuninger
(The Moondog 2A3 amps were one of nine amplifiers surveyed)

Welborne Labs Moondog

This is a 2A3 amp, available pre-assembled from a company that’s otherwise known for its selection of parts, plans, and kits (You can also build your own, for a nice savings). For the price, it comes with the new KR Enterprise 2A3 output tubes. These specially made 2A3s offer more current drive and power output than either Chinese or NOS tubes. In fact, by the end of the review, I had no doubt that the KR-tubed Moondog is the most potent 2A3 amp I’ve auditioned.

It also taught me to never trust first impressions! I was under the impression that this amplifier had been broken in, so I was somewhat disappointed at first, compared to the other amps in the group. But as I listened over the first weekend, the Moondog opened up, and the dark hollow sound that was my initial impression eased significantly. I admit, I expected a lot from this amp, since Welborne’s 300B Laurel was one of the best in my last survey—and the least expensive, to boot!

Heard through the Moondog, the explosive percussion at the beginning of Cnomus all but knocked me back. The cymbal crash and timpani slam was startlingly real. I felt the true power of the orchestra with this amplifier; awesome!

Although big and bold, the Moondog was astonishingly delicate on all the recordings I tried. Inner detail was not glazed over or softened (as with the EAR), though it could do a little better in terms of reproducing ambient space. Its big, explosive sound simply enveloped my room. It didn’t do the soundstaging thing any better than the others, per se—it just seemed to fill the room with more sound. Go figure.

The Moondog’s overall character leans ever so slightly to the dark side of life. It is thick and rich, yet very detailed—the rarest of all combinations. Mind you, it has the lushness of the EAR., but it’s much more incisive. The Moondog is not as powerful as the EAR though, its clipping will sneak up and surprise you, because its sense of punch makes the amp seem unlimited in its power.

The Moondog is a killer amp—and I’m going to build one for myself. I’ve listened to a lot of SETs and this amp along with one other in the group redefines for me both the hi-fi and musical impact of the listening experience. The Moondog is exceptional!

The Welborne Moondog 2A3 Monoblocks
Positive Feedback

Ron Welborne is one of the truly fine people in the world of fine audio. His designs have garnered raves for their combination of aesthetic beauty and wonderful sound. Though I had known of Ron for years, and had friends who swore by his gear, my first direct exposure to Ron’s work didn’t come until VSAC ’98. While at the show, I was quite taken by the combination of detail and sweetness that the Reveille/Moondog synergy provided.

As a matter of fact, it was in the aftermath of VSAC ’98 (which was in the early fall of that year) that Tony and I began to talk about this SET project. (This gives you some idea of the lead-time involved in some of these audio reviews — it ain’t easy to do, amigos! Just ask anyone who’s done it… ) I liked the virtues that I heard there, but wanted to hear it in my own listening room. Even VSAC, which is light years better than your typical big audio show, was not nearly the best place to evaluate what SETs and the Lowthers might do. I wanted to have the Linn CD-12 as a PCM front end, right there next to my trusty fully decked-out Linn LP-12 for the LP sources. Furthermore, SACD had been released since then, and it was imperative that I have a well broken-in SCD-1 when I listened to the SETs.

This was all in place, fortunately, by the time that the SETs started to arrive. When the Welborne Labs gear got here, there was a brief delay while getting the main body of the V20 and Gaincard reviews out of the way. Then I put the Reveille/Moondog system into place, and heated it up for about a week, pumping the occasional music through it before getting too serious.

Ron’s equipment generally comes either in the form of kits, or of fully assembled equipment. The configuration that we listened to was fully assembled. Welborne Labs gives a choice of tube configurations for the Moondog: you can take either the Chinese 2A3’s, the Sovtek 2A3’s, or the single-plate Kron KR2A3’s. (This in the general order of "good, better, best.") The Moondog that Positive Feedback received was tubed with the KR tubes, much to my delight — I had heard much about these, and was eager to try them. Standard power output is rated at 3.25 Watts; the KR’s can be made to deliver 4.5 Watts. The driver tubes are 6SN7’s; the output transformers are made by Electra Print. All wiring is point-to-point, with no PCBs used. As shipped, the Moondog was set for 8 Ohm speakers; not quite a match for the 15 Ohm Lowthers, but OK.

The Reveille preamp is Welborne’s reference piece. It’s a two box dual-mono setup, with a separate power supply mated to the preamp via an umbilical. The power supply consists of two toroidals, each with its own power switch. A pair of high quality stepped attenuators with 24 positions controls volume. Tubed with 6SN7’s, the Reveille is chock full of high quality components (e.g., Caddock, Holco, Hovland) and is wired and connected with Cardas. The Reveille is also non-inverting, a very useful attribute. The inputs are CD, Tuner, Aux/Phono and Tape, all unbalanced. There is one main out and a tape monitor.

The overall impression with the Welborne gear is one of superior quality packaged in a most attractive set of chassis. The walnut trim and polished aluminum finish is definitely a knockout; Ron knows how to build ‘em! I put the Moondogs on a set of Andy Bartha’s Whatchamacallits, which in turn were placed on two Seismic Sink stands, and went off to the races!


The Sound

After the time with the V20 and Gaincard, we were now down into the SET 2A3 trenches: 3-4 Watts, with the kinds of specs that would not attract AES glitterati any time soon. And yet… the sound of the Welborne setup was not what stereotypes would have led me to expect. Instead of rolled-off, polite, or "sweet" reproduction, I found the sonics to be clear, clean, articulate, and well detailed. I was surprised at how much I was enjoying the sense of immediacy and rhythm that the Welborne gear delivered via the Lowthers. While lacking the punch that the more powerful V20 and Gaincard amplifiers delivered, the Moondogs showcased the legendary strengths of the 2A3: a richly delineated midrange, timbral structure, sufficient bass for a quiet foundation to the music, and that certain airiness that is magical!

Another point to praise: the Welbornes were commendably QUIET. No hum, no buzz, no hissing white noise. This cannot be taken for granted; not all designs are so accommodating. I did find that I had to use the Sahuaro’s "easy ground defeat clip" to float the ground with the Moondogs for best noise floor, but once I had done so, I was well pleased with the result.

The dynamics with the Lowthers was also startling. I found that I was able to do most of my listening at 10:00 to 11:00 of volume; no overdriving of the preamp was necessary. At that setting, the Lowthers put more than enough SPLs into the room for comfortable listening, even with groups of 6-8. (12:00 of volume would be enough to drive you from the room!) The Reveille’s presentation of the music was noise-free and neutral, with decent gain; precisely what you want from a fine preamp.

SACDs like the Sony Music Miles Davis Kind of Blue and Sketches of Spain were hypnotic in effect through the Welborne system. Ditto with the SACD of Dave Brubeck, Time Out, or with the very fine Telarc SACD of Brubeck’s 40th anniversary tour of the UK. Or that crème de La crème SACD recording, Ellington: Blues in Orbit — marvelous! It was easy to lean back and rock in my listening chair, close my eyes, and float away on the music. Both the SACD sampler of Joe Harley’s fine recordings, Bluesquest, from Audioquest Music, and Kavi Alexander’s marvelous Fascinoma were magic carpet rides with the Welborne/Lowther tandem in place. Jazz, the blues, folk, small classical solos or ensembles… all sounded delicious with a capital "D"!

My rule is simple: when the toe’s a-tappin’, things is a-happ’nin’!

On the other hand, it is clear that ‘philes who prefer full-range orchestral will have to give careful consideration as to how they will accomplish their discography with SETs. This is not just a challenge to the Welborne/Lowther system, of course; it is a crucial question for any SET. For example, I found that listening to the wonderful Sony Music SACD of Stravinsky Conducts Stravinsky: The Rite of Spring & The Firebird did not have the deeper foundations or the high frequency extension that were clearly presented by, say, the Nova Renditions and the Linn Klimax monoblocks. Or, for that matter, by the 47 Laboratory Gaincard and the Lowthers.

Then again, this is hardly a fair comparison. One cannot — or should not — fault what a system is by pointing out that it is not what it is not. SETs are not, and were never intended to be, high-powered, full range devices, and so cannot be guilty of not being high-powered full range devices. I should also point out that the Welbornes were tapped for 8 Ohms, which meant an unavoidable mismatch with the 15 Ohm Lowther drivers. This may have had some effect on the bass performance of the system, but was not enough to concern either Tony Glynn or myself.

Advice: lovers of full orchestral recordings, as well as those who enjoy rock in its various forms, will have to investigate the properties of their listening room carefully. I found that speaker placement did strengthen the Lowthers’ bass somewhat through boundary reinforcement, though there’s a limit to what can be done with this. (Not to mention the fact that soundstaging and imaging will suffer if you get too radical in pursuing the boundaries!) The Welbornes did fine work within the envelope of the 2A3s, but will not give you the 32Hz pedal on that pipe organ recording that you love so much, nor will it render the opening vocal chorus on the soundtrack to Glory with the profound gravity that it can have (and where so much of the emotion is).

Then again, many audiophiles live in apartments where the successful pursuit of de profundis would lead to an eviction notice, and highly extended upper frequencies would entail a suit for divorce. Not to mention the fact that full range systems are unavoidably large, heavy, demanding beasts with (generally) imposing price tags. Quite apart from musical tastes, there are many circumstances in which SETs may appeal due to the relative ease of setup, relative affordability, and their emphasis on "the glorious first Watt and the midrange thereof!" I can personally vouch for the addictive nature of SETs virtues, which the Welborne/Lowther combination has in spades.

Verdict: the Welborne 2A3s and Reveille paired with the Lowther PM2As are an exceptionally synergistic match, with special strengths in the neutral and detailed presentation of music. Beautiful to the eye; a delight to the ear.


It therefore richly merits Ye Olde Editor’s "Highest Recommendation.

I Never Meet a 2A3 Amp I didnt Like
Welborne Labs Moondog 2A3 Monoblocks
Sound Practices Magazine
Reviewed by Joe Roberts

Nothing in audio is a sure deal but if I were forced to come up with a fool proof recommendation to stake my name on, I would have to go with the classic no-brainer: "It’s hard to build a bad 2A3 amplifier."

There might be some bad ones somewhere but I have to say that every 2A3 amp I ever had the pleasure to hear was at least pretty good and some were downright amazing.

My introduction to triode amps came with restoring a few Brook 2A3 amps of the early 1950s, which I didn’t get to hear until they were certified antiques in the early 1980s. Even in the late 1940s/early 1950s when they were current models, the Brook designs were a throwback to prewar technologies (see SP#2), valued by a few purists who knew that those newfangled pentodes were nothing but a sell out.

The Brook 10C wasn’t even a pure Class A design or anything. It used a sliding bias adjustment scheme to switch the push pull 2A3s way into AB2 when the signal peaked. Yet, despite this elaborate and somewhat dubious conception, the 10C still sounded very very good. Real, real good, in fact.

In an attempt to come up with a simpler amp than the Brook 10C, I built a "Recording Amplifier" (minus the mic preamps). Glory, this was a mighty fine sounding amp and I’d build another one in a second. The "triode sound" is still really there with PP topologies and...Man, you can really get some low end out of a pair of these tubes. After all, the 2A3s were chosen to run a record cutting head because of their good damping behavior even sans feedback.

Yeah, somehow PP 2A3s fell through the cracks in this age of SE mania, but, on the other hand, maybe a single 2A3 amp is about as good as it gets. My first exposure to SE amplifiers was a shot in the dark. I remember looking over a SE 2A3 circuit in the 1940 Radiotron Designer’s Handbook (third edition), provided as an example for calculating the response of the circuit and thinking "Hmmm?"

With a few voltage adjustments, I figured I could scrape a single amp out of my "Recording Amplifier" by hooking the 6J7 straight into the grid of one 2A3. I didn’t have any SE transformers back then. I just ran the DC through the primary of my vintage push-pull UTC LS-55 transformer.

When I turned this Frankenstein on I was floored. It sounded way better than it should have. It was a looser, more open, more organic sound than the PP 2A3, and although the bass wasn’t as tight as the PP amp, it was very expressive. This experiment was obviously taking me somewhere I thought I might like to be.

Now, after years of study and experience, I might comment on how the 6J7/2A3 combo is reminiscent of the classic WECO Model 91 pentode driver/300B circuit and blabber on in an Ultra-Fi "dress-to-impress" patois about esoteric bullshit that doesn’t matter anyway. Seems like everybody is a triode amp expert today, but back then I didn’t know anything but what I was hearing. That’s all I needed to know. The rest is history.

One of the things that I know now that I didn’t back then was that Nobu Shishido, one of the "crazy Japanese guys" who revived the triode amp, wrote the first article about SE in the modern era in a Japanese experimenter mag about a 2A3 "Loftin-White" he originally built from dumpster TVs while an MBA student in Oregon during the late 60s. He didn’t "go single-ended" to be hip. It was a cheap and easy way for a poor tinkerer to get some music playing in the dorm. Anyway, that amp ruined old Nobu for life.

The last SE 2A3 amp I built was inspired by JC Morrison’s degenerate Loftin-White lash-up called the Micro 3.5 from SP #6. The custom features of my implementation included a bank of Western Electric oil caps and a tasteful pink-and-white speckle over gray primer paint scheme. There were only a few lonely parts underneath that big, ugly "budbox" chassis, making it an air box beyond anything ever dreamed up by the mass marketeers.

Also, I used indirectly-heated 6A5-Gs instead of directly-heated 2A3s, which sounded just like real DHT 2A3s to me but there was zero perceptible background noise even on a horn. It was a weirdo, one-off creation and no big looker, perhaps, but this amp kicked ass and took names, I swear! I gave the 6A5 amp to a Korean friend of mine, who eventually lent it to a hi-fl magazine editor back home. The editor has since refused to return it, probably because it sounds better than almost anything you can buy! No surprise there. Look, it showed up in the pages of a Korean audio mag!!

Nobu Shishido probably loves the 2A3 as much as any man who ever walked the earth, but he has moved on in his own technical/aesthetic quest to exploring the grid circuits of transmitting tubes and the practical work of restoring old opera 78s. He downplays the 2A3 with a been there, done that attitude- "Sure the Loftin-White was a great amp but if it was that great why isn’t everybody listening to Loftin-Whites?"

I’d be the last person to argue against audio diversity and the forward march of progress, but I do believe that everybody should be required by law to enjoy the pleasure of a good SE 2A3 amplifier for a while. There is great reference value in knowing how much you can get with so little.

Fortunately in this day and age, you can buy super-quality parts to put together a 2A3 of your own, or buy USA-made 2A3 amps, your choice of finished or kit form. For the last 60 years, you had to really work to hear 2A3s, but now it’s probably easier than it’s ever been. That is a strange historical fact and the more I think about heavy historical facts like that, the more I want to stop thinking, spark up a 2A3 myself, and just listen, if you know what I mean.

I really like the name of the Moondog 2A3 monoblocks from Welborne Labs, and not only because there is a certain timeless quailty of regularity and dependability evoked by that lunar imagery. The cyclical theory of history implied by the endless gyrations of the moon kind of fits with the resurgence of this ancestral audio tube, for those who like a little millennial poetic justice and tidal forces with their audio gear.

Beyond all that deep interplanetary symbolism, the name Moondog dares to speak the obvious truth...that anybody who has to have a 2A3 amp is probably too far gone into audio lunacy to relate to normal society anymore.

And Ron Welborne is in a good position to know about that freaky triode crowd. Hey, Ron, do sales go up during the full moon or what? After all, you came up with the name, buddy!

Consistent with the access to ancient natureal secrets and dedicated insanity implied by the Moondog title, these amps feature the kind of classic tecnology that is hard to aruge against. GZ-37 tube recitifier with a Pi-filter using a choke, a pair of 6SN7s and a 2A3. Output transformer is the MagneQuest DS-025, my personal favorite Philadelphia-wound transformer.

This amp is a solid, traditional, and somewhat conservative design and, in those respects, it represents what is worth keeping from the retro concept. Except for the DC heater supply for the 6SN7s, the Moondog is a throwback to a long-dormant 1930s all-triode amplifier paradigm, back from the ashes to play the music for the turn of the century.

Although I might have an intellectual reaction to a circuit, in one way or another, I don’t really know how to think about the sound of a given circuit. A circuit is just an abstract picture until you build it out of real-world parts. And it is a particular combination of parts that gives each amp its actual sonic character. Often in my experiments with things like 2A3 amps, I found that a coupling cap swap could impart more flavor than installing a whole new driver stage.

That being said, I still feel good about the Moondog schematic. You won’t get burnt sticking with a classic framework like the two stage medium mu triode Moondog voltage amp stage and a 2A3. This approach has become a classic for many reasons, one of them being that a simple circuit that sounds good is a tested recipe for satisfaction. Getting fancy isn’t always the point.

The Moondog might borrow from bygone traditions, but this amp does not sound very antique at all. I believe that’s because of those modern hi-tech components. In these simple, no-feedback amps, you can really hear the parts, every single one.

In the instruction manual, Ron Welborne says that at first he tried the vintage carbon resistor and oil/paper cap scheme and they were impressed with the tonal results. Then, after swapping in some boutique bits from the Welborne parts catalog, such as Caddock foil resistors, a couple Mills wirewounds, ELNA Cerafine caps, Hovland MusiCaps, and whatnot, Ron felt that they had to go with the fancy stuff for modern audiophile performance aspects, like big soundstaging and sonic detail resolution.

Welborne, ever eager to please, is willing to customize the kit per the customer’s individual audio fantasies, so if you’re after something special, give the man a call. It’s a a kit, after all, so if you want to mellow it out with an oil cap or whatever, who’s gonna stop you? Certainly not Ron Welborne. He’ll even sell you the damn oil cap!

On the whole, the quality of the hardware and components that go into the Moondog kit are on the level to be expected from a specialist parts guy: Cardas connectors, OFC wire, name brand components out the wazoo. The Moondog package doesn’t go over the top with swank and elaboration but there is no junk in sight.

The Moondog monos are packaged in the brass plate and walnut wood frame style seen before with the Laurel 300B amp. The look is natural and unadorned with a sort of rustic manly character. The amps look handcrafted rather than mass-produced; which is exactly what they are.

Like I said before, I think it’s those newfangled Welborne Catalog components, but the Moonlog I heard, Ron’s personal stock Moondog, tunes the antique 2A3 for the modem 1990s wide bandwidth, high-resolution aesthetic. The 2A3 is capable of presenting an astonishingly natural, high-definition 3-D scenario and this amp showcases that impressive trait.

This is one of the important things triodes can do: that very detailed presentation with enough harmonic depth and color to get the emotional encoding of the tones across. In my opinion, the added color imparted by the 2A3 is just what is needed to warm back to life that cold analytical concept of x-y-z axis positioning as a goal for hi-fi systems. Perhaps some "imaging" is necessary for realistic musical portrayal, but it is not in and of itself sufficient to get the illusion across. Imaging for me belongs to the intellectual side of recorded music listening, not the immediate physical communication part. Without that special expressive juice behind it, the image is just a skeleton-the dry, objective component of phonographic realism.

The way some SE triode amps get the audiophile transparency illusion right without sacrificing the vivid life and tonal complexity of music has been a hit with a lot of listeners, including me. Such amps can be shockers to hear.

A clear-voiced 2A3 is especially good at sneaking up on you every once in a while with realism that is scary. Like a bell sound out of nowhere that makes you jump out of your chair. Or how Miles’ horn on Live at the Blackhawk cuts through the air like a flare. How could anyone not like this magical effect that I’m trying so uselessly to describe?

Since the Moondog is being offered in a package arrangement with Lowther Club of America, which I took to suggest a recommendation of the Lowther/Moondog combo, I had to try it with my PM6As in Medallion cabinets. Indeed, Welborne picked parts using his Lowther PM2A as one of his main reference speaks, so there ya go.

No shock then that the pairing really clicked, as expected. The Moondog supported the high-res well-lit effect of the paper cone Lowthers. The incisive midrange added realism where a more flabby mid would have steered the PM6As toward the boozy, lush flavor I got with a lot of my other SE triode amps on my Lowthers. There was something to be said for the tasteful restraint of the Moondog in this system configuration.

The Moondog also led me to rethink my theory that I really want some feedback on the Lowthers to add control the rear-loaded horn bass. Most no-FB SE amps I’ve tried on the Lowthers sounded gorgeous in many ways, but more often than not were underdamped in the bottom register.

However, to my amazement, the no-feedback Moondog played with excellent low end control, thanks only to the reasonably low damping factor provided by a naked 2A3. The tightness, definition, and punch were right there. Vibrations emanating from tightly-stretched membranes sounded like they were coming from tightly- stretched materials. Good job on the low end.

According to Welborne, most of the people who have been buying the Moondog kit own Altecs, Lowthers, Klipschorns. The K-horn fans are particularly nirvana-stricken with the 2A3s, fitting since Paul Klipsch used Brook 2A3s back in the olden days. Altec, Klipsch, etc... these are all obvious candidates, but I believe that the clear, crisp, and well-damped character of the Moondog would serve the amps well in the quest for matching speakers among the contemporary crop of audiophile boxes.

And if you find yourself in a situation where you think a bit more whatever is in order, remember that it’s a kit. Feel free to screw around!


COMMENT

Obviously, I liked both 2A3 amplifiers that I heard quite a bit. Although I purchased the Fi"X" before ever hearing the Welborne Moondog, I was never stricken with buyer’s remorse. Really, I would have felt the same way if I bought the Moondogs. Ahhh, 2A3 amps; I love ‘em. These are the kind of amps I started building in order to enjoy. I’m really glad to see that you can go out and buy kits and amps like this now.

With compression drivers, I like a dash of romantic excess in the amp. These TAD 2001 drivers sure don’t donate any romantic excess to the system. If I owned the Moondogs, I might try sticking in an oil coupling cap for compression driver use, although many would prefer the clean, low-distorton act of the stock amps. Tough to say. What I think I want isn’t always what I actually want when it’s playing there in front of me.

On the Lowthers, both amps again did a good job. The Fi 2A3 came across gutsy rich, and punchy with a full, slightly puffy, and emotive bass. The Moondog shifted my attention upward in frequency to the ultra-clean midrange and sparkle effects but had a low end that was surprisingly crisp and well-articulated for a NFB flea power amp on that rear-loaded bass horn.

Listening to these amps, it was hard to shift into an "amp shootout" review mode, because they both sounded so good in their own ways. I just wanted to sit back and listen to what the amps were doing.


SPEAKERS

Two of the big reasons 2A3 amps like the X and Moondog aren’t more popular is that 1) Most people haven’t heard anything like this and don’t know how good it can be and 2) It does require a leap of faith to expect that there are speakers that 3W will drive. It is definitely difficult to believe, based on the usual preconceptions, that three watts will drive anything. All I can say is "ha,ha,ha."

I used to think I needed fifty watts at Least. Now I can bridge the power outputs of my five favorite amps, and the total wouldn’t even hit fifty, probably closer to forty, watts.

Obnously 2A3 and 45 amps are tailor-made for what I like to use ‘em for....efficient multi-amplified horn systems. Indeed, with a horn, power ain’t nothing but a number, and you can totally ignore the specs and select amplification on the basis of musical performance criteria alone.

One reality we can never get beyond is that there is always a moment of mystery when you hook up a new amp and speaker combination. The challenge is a bit more obvious when the amp is a three-watter, since engineering feats like high-power and feedback are intended precisely to reduce the mystery of the speaker drive equation, and single 2A3 amps do it without those technical advantages.

On the other hand, at least the 2A3s are great sounding amps, which can’t be said for many "drive-anything" amps, because what you have to do to "drive anything" is not free in terms of sonic tradeoffs.

It’s easy to overplay the case that three watts is more useful than one would think, for these are indeed very low powered amplifiers that we’re talking about. However, except for stupid combinations like Apogees or Magnepans + single 2A3s, I think that the quality and quantity of music that single 2A3s would put out on many "normal" speakers is worthy of respect. Three watts will get some sound out of any speaker, not to say that it would be anything great to hear in many cases.

As for specific speakers, well it either works or it doesn’t. Only trying it will tell you if a 2A3 will play loud, play only at low-levels, or not at all on a given speaker. It would be nice if there were some specification that would tell us what we want to know, but there ain’t no such thing, unfortunately.

Speaker sensitivity helps but may not be important as highish (>8) impedance and general voodoo synergism that applies to system matching. Simple or no crossover designs seem to work out a little better than lossy complex networks, for obvious reasons, but anything is worth a shot because you never know.

Now that the speaker makers are hip to horns, isn’t it time for the single-driver full range revival? Man, that’s what we need. I still don’t think I ever beat that pair of Altec 755A eight-inchers in 2 cu.ft. wall cabs that I had when I first started messing with low power. Lowthers are good but let’s have something we can just stick into a plain old rectangular box and be done with it.

In various pockets of the globe, full-rangers like Diatones, Fostex, Supravox, Siemens, have their devotees, but the US scene never got hip to this classic low-intensity approach. True, single-cone drivers usually can’t "do everything," but, for this kind of thing, it’s more important how well they do what they do, mainly the mids.

The way not to try a 2A3 on a "regular" speaker, exactly the way most audiophiles would probably do it, is to pull out an old copy of The Sheffield Drum Record or "1812" and immediately crank the program up until the amp clips. Sure, it will clip. What did you think?

The right way to try out a low power amp with a "regular speaker" is to go ahead and listen to music as you ordinarily would and see how it works out. What usually happens is that it sounds pretty good, but while you’re listening, dreams of horns start dancing in your head. What can I say?

It’s strange that amp choice decisions are so often tied in with the speakers already in the listening room, when what we’re doing is looking for a new amp right? Let’s face it, a more productive system-building logic and more satisfying recipe for personal happiness would be to go out and buy the damn 2A3 amp first and then look for speakers that will work with the new amp. The truth. You heard it here first, fellas!

BUILD THE WELBORNE MOONDOG 2A3 KIT
AND TRANSFORM YOUR LIFE
by Harvey "Gizmo" Rosenberg

....What was synchronistically spooky about this note was that “Bob” was the friend who helped me in the 1955 overcome my fear and build my first Dynaco. (The Moondog is more complicated than a Stereo 70) Bob Schildkraut was the ultimate science nerd at Lynbrook H.S.(went on to MIT) had the most expensive slide rule, zits, thick lens glasses, never talked to girls, and knew everything about tube circuits. I finally got up the courage to approach him and ask him if he would teach me how to read a schematic and master Dynaco.

Can we walk the walk and talk the talk dude? You can’t get from here to there without some brother’s help. You can’t learn how to ride a motorcycle unless you reach out to a brother. You can’t learn to shoot and hunt unless you reach out to some skillful brother. You can’t learn to fling a flyline and catch a trout unless a brother cares enough to respond to your “Will you help me”. You can’t learn how to climb a mountain unless you reach out to the master, and humbly say....” Will you help me?”. The process of mastery doesn’t begin until you grow up, become a man and have the courage to ask ..”Will you help me....I want to learn what you know”. And so it is with learning how to build a tube amplifier. You must reach out and find a brother who will share his skill. (In Japan where there are well organized “tube audio schools” this process of bonding has become institutionalized)

Let me assure you that learning to build a tube amplifier is much easier than learning how to shoot and hunt, fly fish, ride a motorcycle, and mountain climb...all of which are far more dangerous than soldering.

Even if you graduated with a degree from The Dumb School of Cooking, you can learn how to read a schematic of a single-ended triode amplifier. If you can zipper your fly and wank you have the manual dexterity to solder a beautiful joint....but someone is going to have to initiate you in the process.

Does this seem complicated? Try paying someone (your local TV repairman) for their time because what ever expense you have will soon save you thousands of dollars, because once you can build your own equipment you will be able to build better tube amplifiers than you can buy in any store in America...trust the truth of that statement.

You can use the chat groups and local classified ads to find your solder slinging bro’. Here is a sample ad: Help Wanted: I want to build my first tube amp. Need training by technician who knows tube circuits, can teach me how to read schematics, soldering and how to us volt meter. Payment by the hour.


RON SAN

Most of you don’t know Ron Welborne, but if you met him you would swear you were staring at Toshuni Mifune in The Seven Samurai. Ron usually walks around in a simple Samurai robe and in the place of his sword is a very sharp and deadly wire stripper. Ron is such a skilled wire stripper that he can strip wire with his eyes closed while being attacked by a transistor amp.

Why does this matter?

Ron probably creates the most Japanese style amplifiers in America, and that is a very good thing for you..and by style I mean the piety of thermionic righteousness. This style is something that Americans are just beginning to get. You can observe this style in the Sun Audio products, and there may be other tube savants who are following this path of beauty, but I haven’t encountered them yet. (Nori Komura and Gordon Rankin are following this path, but I haven’t auditioned their works of art) What I am saying is what you know...parts quality and layout in single-ended circuits matter a greater deal because of these circuits ability to reveal the quality of dust on their tubes. But now we are talking about being able to buy a amplifier kit for way under $2K that will make you cream very economically.

This is designed to be an all hard wired kit (no circuit boards) and to exploit the best quality parts, and that includes Cerafine power supply capacitors, the best quality polypropylene and oil capacitors, super deluxe resistors, and a wire layout that maximizes tonal integrity. It employs, as does all of Ron’s amp kits, a choke and tube rectification, because to do other wise would be dishonorable for this, America’s Samurai of directly heated triode kits.

The chassis, because of its wood base and brass top plate, reminds me of a fine sailboat and that is very swell and separates this kit from the those kits that are the less expensive entry level products. Do you get my drift...this is a kit in the Japanese tradition of kits being designed for the man who doesn’t want the compromises inherent in store bought amplifiers.

This kit also exploits Electro-Print transformers which I can confidently tell you are superior to most transformers that are used in commercial products, and it is obvious that this is a big factor in the quality of this amplifiers aural matrix. These transformers, according to their specs, have a primary impedance of 3400 ohms which is right in the middle of the debate of 2,500 vs. 5,000 ohms...power vs. low distortion.


TALKING TO MOONDOG

I may be the only triode savant who ever talked to Moondog, who was a very strange blind musician who stood, during the late 1960s, on the corner of 6th Ave and 54th Street every day in New York City, dressed in American army blankets/pagan monk with a staff. I also owned his two records which were very strange and beautiful.


BUILDING THE MOONDOG

Ron San is probably right when he says this shouldn’t be your first kit, but then again, if you have bonded to your solder slinging bro’, who is guiding you, this amplifier is very simple to build because of the very open mechanical layout. But most importantly is the quality of Ron’s instruction manual which is the best kit assembly manual I have seen since the Dynaco 400 Kit instruction manual (Does anyone remember that?). There are beautiful clear drawings, colored lines and precise check off instructions. My only complaint, and this is serious, is that there are no instruction on what type of cigars to smoke, what kind of brandy to sip and what kind of music to listen to while working on this project...and...this is very peculiar for such a Samurai....no purification ceremony is indicated before the work begins. But I can forgive Ron San for these omissions, which I know he will correct in his instruction book after he read this criticism.

And the best news of all...if you should fall in love in the middle of this process with a Cameron Diaz look alike and loose interest in finishing, you can always send the unfinished kit back to Ron for completion for a very reasonable fee. I really don’t suggest this because very soon you will loose interest in the faux Cameron and your priorities will get back on target.

Ron San is also treating you like an adult intelligent human....he announces what we all know...you can tune a single-ended amplifier very simply by changing the type and brand of coupling capacitors or some strategic resistors, and even encourages you...(the man whose IQ that is above normal) to experiment. Bravo Ron San. Personally I think that anyone who manufactures a single-ended tube amp that employs RC coupled circuits that doesn’t encourage this activity has chicken shit for brains..oops....I slipped and talked like a biker...forgive me.


WHY SAVOR 2A3 CREAM?

There are three 2A3 paths...

(1) You have ascended to the 300B path and have been enjoying the taste and aroma of this cream and you are now, like all restless artistic men, wanting to experience something new. It makes sense to ascend to more micro power which is ascending to less power.....and yes it is absolutely true that we are talking about an extremely refined form of directly heated triode cream.

On this path you have the opportunity to experience the wonder and mystery of the KR 2A3, which is in league way above the Chinese 2A3 in its ability to put on a magic show. Again I am at the frontier of my linquistic ability to describe the ineffable beauty of this KR tube realized in the Moondog circuit.

On this path you may have reached the spiritual maturity to dive into a tube crossover and have decided to use your 300B on the woofer and 2A3 on midrange/tweeter, and this is a stunning combination and the Moondog is one of the best ways to implement that strategy.

(2) You are intrigued by the Lowther driver which can only be used with a 2A3 or 45 amplifier...according to the collective wisdom of the tribe, and based on my limited experience with this driver...right on! What I like about this combination is that it is exactly the right formula for lasting love, which always demands equal doses of suffering and pleasure...just like a horn loudspeaker. Lowthers are all about commitment, tuning and spending hours enjoying their spookiness...high efficiency, alnico, no crossover, which may be the only way for a reasonably sane man to experience the alchemy I have been preaching.

Check with Ron on the special package he offers of Lowther drivers and amplifiers...very smart....and remember you can tune this amplifier many different ways which is part of the joy of Lowtherosity.

(3) You just want to be cool. I never sit in judgment of my fellow dude, and I understand the pressure that we are all under. This is not an easy time for men, where most men are giving dogs a bad name. It may make sense to buy these amplifiers, even if you can’t use them, just to tell your friends that you are using a 2A3 amp.


WHAT IF YOU ARE TOO BUSY WITH YOUR BOWLING LEAGUE?

As of this moment these are the most refined 2A3 amplifiers I have auditioned and Ron San is prepared to sell them to you at $2,000 per pair fully assembled with Chinese tubes, making these amplifier still a bargain. If you can’t afford the KR tubes now, save your money and buy them later...they transform this amp to a higher dimension of cream. I also suggest using NOS RCA 6SN7s, and using 5U4 rectifiers....but remember experimentation and tuning rules!


WHY THE GUILDMEISTER IS LOVED AND DESPISED

It is increasingly apparent that the edge of the audio arts is not being dominated by the big tube manufacturers but by the passionate thermionic artisan, like Ron Welborne, who gives you the benefit of extremely high quality circuitry of enormous refinement, without having to pay the retailers profit margin.

Building a single-ended amplifier kit is an important initiation because it totally alters your relationship to the audio arts, and Welborne kits, as far as I can tell is the best America has to offer. Go for it. Check out Welborne Labs web site for more information.

Tune in for more of my experiments with Moondog.


LET ME KNOW YOUR 2A3 EXPERIENCES


Anyone who has some creamy info about the joy of this tube let me know...especially what speakers work well.