The Triode Lab 2A3i resembles the Ongaku in more than just its ability to have me break out in goose bumps. Its size and layout are actually directly inspired by the venerable Japanese. As a result, the 2A3i is a very large integrated, so large that it did not fit on the bottom shelf of my rack and stuck out a good two inches in front and behind. This has more than just aesthetic implications. Because the component is much longer than typical—and unless you owned a dedicated amp stand that you can turn sideways to accommodate the beast—the high-quality footers included with the 2A3i can't actually rest on the shelf and will hang over at both ends. I had to rest the amplifier on four Isolpads beneath its chassis to set it in place. In addition, this narrow and long design relocates its input connectors to the front left of the chassis, not around back as is the convention.


Depending on your rack and interconnect length, this can create other challenges. But this is no gratuitous layout. If you look closely, it allows for the shortest distance between the inputs and the first gain stage, followed very closely by the second stage and then the power triode to end with the output transformers located on either side of the amp. This very critical signal path progresses in a completely linear fashion across the first third of the long chassis for very short connections and optimized layout.


In addition, it locates the AC power input, rectifier and line transformer way to the back of the chassis nowhere near any critical musical signal. Simple but effective, it results in one of the most silent SET amplifier I have ever tested. The price to pay is a big and cumbersome chassis that won't fit on any shelf meant for conventional components. In my book it was well worth the hassle but only you can decide that for your own system. Wrapping up introductions, the 2A3i is nicely built and finished but at this price point we are not talking massive aluminium enclosures and shiny chrome. Triode Labs' philosophy is to put the money into the components, not bling. So yes, the 2A3i is elegantly Spartan in appearance but there is absolutely nothing Spartan about its sound.


To oversimplify things, I would classify triodes by a few affinity groups. The most common would be the 300B which is typically very midrange focused, warm, a bit shy in the treble, slower and fatter in the bass but delivers that 3D triode flow and scale at greater quantity than others which also means more distortion and smearing than most. One can substantially change its character with massive silver wiring and transformers like Samuel Furon does. Still, more often than not, a 300B amplifier from Trafomatic or Yamamoto will get you a variation on the attributes described.


No matter how gifted the designer, you won't get a transient happy, tight-bass 300B single-ended even if some of the newer bottles and 300B replacement attempts mean to address those weaknesses while also risking to sacrifice part of the magic in trade.



The 211 can sound like a more powerful 300B or, when treated with a lot of respect and money, turn into a fast, refined, tight and transparent triode. If you spend less than $15'000 on a 211 amplifier, you are likely hearing category number one, not that money is a reliable indicator of quality. It's simply that getting all a 211 is capable of seems to require silver wiring and quite expensive parts, especially massive custom transformers which can be very expensive to source. The 845 seems to follow a very similar pattern, slow and fat but capable of a lot of refinement in a few select amplifiers like Wavac. Just so, I have still to hear one that completely eradicates the treble glassiness from the 845. With its typical 2.5 watts, the 45 triode falls into the micro-power category. It makes 300B and 211 look like giants with their 8 and 12 watts respectively. I find the 45 tube to be one of the best to provide that 'lit from within' more ephemeral character to voices and violins, with a fully extended and refined treble which explains why it often is the tube of choice for treble and midrange amplification in multi-amplification horn systems.

In that family, the 2A3 ends up being the forgotten child. In most circuits it is easier described by what it doesn't do rather than by what it excels at. In the vast majority of designs I had heard until now, the 2A3 offered slightly more power than a 45 but at 3.5 watts not enough to make any meaningful difference. Its top end was never as refined as a 45, its bottom no tighter than a 300B yet for some reason it delivered less triode magic than either of those. Hence my private 2A3 assessment until now had been ‘blah'. Yet what the Vinnie Rossi Lio DHT DAC/preamp Srajan reviewed very favourably and the Triode Lab 2A3i now seem to prove is that like with any other triode, implementation is key in determining the final sonic personality of the gear.