Since then, the Dutch have claimed other engineering and technology triumphs that aren't quite so dicey. Take the world of audio. Dutch innovators at Philips gave us the audio cassette (for which I beg your forgiveness). Two decades later, they and their Sony colleagues upped the game with the Compact Disc—and randomly decided on the diameter of the center hole by making it exactly the size of the pre-Euro Dutch dime. A Dutchman came up with Bluetooth. Top high-end brands like Mola Mola and Hypex hail from the Netherlands (footnote 1).

So does PrimaLuna. For almost 20 years, the company has built a solid reputation making high-quality tube gear—that still offers remarkable value, even after the price of its cheapest products rose from $1095 in 2003 to $2795.

I own the PrimaLuna DiaLogue Premium HP power amplifier. It's superb. So I didn't need much convincing when Stereophile Editor Jim Austin tasked me with reviewing the company's top-of-the-line integrated tube amplifier, the EVO 400. After it spent almost three months in my system, I can safely say that in contrast to the story about Mr. Coster and the printing press, there's nothing hyped or sus about the praise this product has received.

Care and feeding I have a checkered history with tube amplifiers, and some of that is my own fault. One morning two years ago, when I was reviewing for a different publication, an amp arrived for audition. I plugged it in, and only when a wisp of smoke accompanied the puzzling absence of sound did I realize that, while I'd neatly rolled out the speaker cables, I hadn't actually connected them to the binding posts. The replacement fared better, and the sonics were enjoyable, but frequent fluttering noises made for a mixed experience. I never did write that review.

For me, choosing sides in the old tubes-vs–solid state debate is a Solomonic ordeal. I often love the sound of tubes (in the right system), but that soothing, seductive signature is offset by the care and feeding that tube technology seems to require. Plug in a solid state amplifier and you're good to go, probably for decades. Plug in and turn on a tube amp and you've got responsibilities. Depending on the particular model, you may have to make sure there's always a load on the terminals before plugging it in and remind yourself to adjust the bias from time to time (although PrimaLunas, admirably, are truly autobiasing). You also can't help but listen for tubes that are possibly sputtering toward death. You'd best have spares on hand when they finally croak, and be prepared to spring for an entire fresh set every so often. Which, especially in times of tube scarcity—I'm looking at you, Russia—can tax budgets.

In my experience, which goes back 25 years to an otherwise very fine Mesa Baron power amplifier, tube components are also more susceptible to hum and other unwanted noises than their solid state counterparts. I've even seen disquieting arcing in a factory-fresh tube preamp. Then again, my PrimaLuna DiaLogue power amp, ca. 2016, has never exhibited the slightest bit of trouble; there may be truth to the company's claim that its products are built to last a lifetime. I've also had zero issues with my Black Ice (formerly Jolida) FX10, a pint-sized, wallet-friendly little tube (ch)amp that has no business sounding as pleasant as it does.

About now you might expect me to write a paragraph about how my time with the EVO 400 was also puppies and roses. Well, not quite, but close. No excessive drama transpired, but a few weeks in, first one and then another of the amp's six stock Psvane 12AU7 tubes started making fluttering noises through the speakers, so I swapped in new ones. Luckily for doubters, PrimaLuna warrants the tubes for six months, the amps themselves for three years.

When I asked California tube guru and PrimaLuna importer Kevin Deal about the duo of uncooperative 12AU7s, he said it could simply have been a break-in issue: "Sometimes a new tube that gets a little noisy just needs to be reinserted or moved." He added that his company, Upscale Audio, has retubed about 75,000 components and that many tubes that people send in as faulty test fine. "A tube that's noisy in a gain stage may be perfectly quiet as a driver or phase splitter."

Everything else about the EVO 400 was hunky dory. No hum emanated from the speakers or directly from the amplifier, not even when the room was dead quiet and I placed my ear practically against the drivers of my Tekton Moab speakers, which have a specified sensitivity of 98dB.

That's not happenstance, explained PrimaLuna founder Herman van den Dungen after I emailed him to ask about his design approach. "We're not the best salespeople, so we need good products to still make sales. High reliability and good aftersales service help us do that. I'm not a masochist—if necessary, we'll repair with a smile—but we'd rather smile because a repair isn't necessary."

PrimaLuna claims its tube gear has "a negligible defect rate of just one-half of one percent—unheard of in the industry—which makes it more reliable than a lot of solid-state gear."

The EVO 400, priced at $5595, sits at the top of PrimaLuna's integrated amplifier line, lording over the EVO 100 ($2795), the EVO 200 ($3395), and the EVO 300 ($4695). The 400 costs about $1400 more than its predecessor, the DiaLogue Premium HP integrated, did when that amp was introduced eight years ago. About half of that increase is inflation; the other half is attributable to higher-quality parts and extra features, including fatter transformers, upgraded diodes, higher-end Takman resistors and DuRoch tinfoil capacitors, a tape-monitor circuit, stereo subwoofer outputs, plus the fact that the EVO 400 is prewired for an optional PrimaLuna moving magnet phono stage ($249; not tested).

Getting an up-close look Weighing in at 68lb, the imposing EVO 400 is a marriage of gleam and substance. A black or silver fascia—your choice—fronts a chassis with an attractive gray-blue automotive finish, applied in five coats. On the left, a volume control operates an analog Japanese ALPS Blue Velvet potentiometer. On the right is an input-selector knob with positions AUX 1 through 5 plus a sixth marked HT, which lets you turn the EVO 400 into a power amp for driving the left and right speakers in a home theater. Up top, an arched array of six 12AU7 mini triodes forms the front row of tubes. The two center valves do preamp duty, while the other four are the drivers for the two rows of EL34s (eight in total). Each EL34 has a red LED next to it that will light up when that tube goes bad, removing some guesswork.

On the back of the unit are 4 ohm and 8 ohm speaker taps, an IEC C-14 power receptacle, all the aforementioned inputs, plus the tape and stereo subwoofer outputs.

A fat, two-way power switch protrudes from the amplifier's left flank. On the right are two more switches: one for moving from speakers to headphones (there's a ¼", single-ended headphone output on the front), the other to accommodate either the stock EL34 tubes or aftermarket high-bias valves like those from the KT family. (I found the Tung-Sol KT150s especially enchanting when I tried them for a few weeks.)

Inside the chassis are massive toroidal power transformers that the company encases in a non-microphonic resin for noise reduction. The equally beefy output transformers are wound in-house, and the entire signal path is wired by hand using Swiss-made, silver-plated oxygen-free copper wire. The hyper-tidy layout looks like it's done by someone who really likes Marie Kondo.

Footnote 1: It's not a coincidence. Dutchman Jan-Peter van Amerongen, who died late last year, founded Hypex in 1996 and later hired Bruno Putzeys as the company's head of R&D. Amerongen and Putzeys later cofounded Mola Mola.

Log in or register to post comments COMMENTS Lovely writing Submitted by philipjohnwright on May 18, 2022 - 12:33pm It flowed for me in much the same way I think the Evo 400 did for you. Log in or register to post comments KT150's or the EL34's preference? Submitted by Glotz on May 18, 2022 - 2:55pm Or I assume it was more complex than that..? Log in or register to post comments fine review Submitted by windansea on May 18, 2022 - 11:34pm Enjoyed the mentions of Mesa Baron and Jolida. A Jolida was the first tube amp I heard, back in college. And I still use Mesa, but for my flying V not for hifi. I don't find tubes to be that tricky, but it's true that some work better for some purposes than others (echoing Kevin Deal's comment). For 12AU7s in my preamp I have NOS Telefunken and a bugle boy, and for unknown reasons, the music sounds more alive with the bugle boy in the gain stage and the tele as cathode follower. I have Psvanes in a smaller setup, but my ears prefer the NOS tubes from reputable sellers (not ebay), especially for line-stage amplification. Log in or register to post comments Comparison to other PL Integrateds Submitted by imbruceleroy on May 19, 2022 - 8:16am Thanks for the thoughtful review Rogier. I'm just getting into the HiFi universe and am, naturally, tube-curious. Question to all: Can anyone speak to the differences in sound of the 400 as compared to the other PM integrated amps down the food chain? 300, 200, etc.? I prioritize sound-stage and transparency and never play loud. Wondering if the same sound signature that Rogier described can be had by stepping down the line. Thank you in advance! Log in or register to post comments bhkat Submitted by bhkat on May 19, 2022 - 11:09am I thought that the size of the compact disc was chosen so that it was possible to fit Beethoven's 9th symphony on one disc. Log in or register to post comments

It flowed for me in much the same way I think the Evo 400 did for you.

Or I assume it was more complex than that..?

Enjoyed the mentions of Mesa Baron and Jolida. A Jolida was the first tube amp I heard, back in college. And I still use Mesa, but for my flying V not for hifi.

I don't find tubes to be that tricky, but it's true that some work better for some purposes than others (echoing Kevin Deal's comment). For 12AU7s in my preamp I have NOS Telefunken and a bugle boy, and for unknown reasons, the music sounds more alive with the bugle boy in the gain stage and the tele as cathode follower. I have Psvanes in a smaller setup, but my ears prefer the NOS tubes from reputable sellers (not ebay), especially for line-stage amplification.

Thanks for the thoughtful review Rogier. I'm just getting into the HiFi universe and am, naturally, tube-curious. Question to all: Can anyone speak to the differences in sound of the 400 as compared to the other PM integrated amps down the food chain? 300, 200, etc.? I prioritize sound-stage and transparency and never play loud. Wondering if the same sound signature that Rogier described can be had by stepping down the line. Thank you in advance!

I thought that the size of the compact disc was chosen so that it was possible to fit Beethoven's 9th symphony on one disc.