PrimaLuna EVO400 integrated amplifier

National pride is the damnedest thing. When I was growing up in the Netherlands, schoolchildren were taught that the inventor of the printing press was a Dutchman named Laurens Janszoon Coster. Germany's Johannes Gutenberg was waved away as an also-ran, if he was mentioned at all.

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.
Durob Audio BV
US distributor: PrimaLuna USA
1712 Corrigan Ct.
La Verne, CA 91750
(909) 310-8540

philipjohnwright's picture

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

RvB's picture

Thanks for that kindness — glad you enjoyed the review!

Glotz's picture

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

RvB's picture

...I wouldn't say the amp is in any way hamstrung with the stock EL34s. It sounds lovely either way. With the KT150 valves, I get marginally better control of the lower bass, and a more expansive soundstage. It's not night and day though. If you do decide to try the KT150s, I'd wait a while until prices stabilize. The tube market's kinda crazy right now. I have a feeling that tube costs will be lower in the fall, or whenever Russia decides to end its ill-advised invasion and sanctions are lifted.

windansea's picture

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.

imbruceleroy's picture

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!

RvB's picture

...there's no significant change in sound signature when you go from the 400 to the 300. I've never heard the 200 or 100 so I can't really speak to that. The folks at Upscale Audio should be able to help. My guess is that as long as your speakers are easy to drive, you'll get nearly identical sonics from the "lower" models. Inefficient speakers will do better with increased amplifier power though.

There's also a PrimaLuna owners group on Facebook where everyday users are probably happy to answer your question:

bhkat's picture

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.

Barry Michael Okun's picture

He said the HOLE in the center of the disc, not the disc itself.

PS -- Love this amp. LOVE LOVE LOVE it. My balm during The Lockdown.

Oldsport's picture

Got one from Upscale for the livingroom. The sound is inviting, relaxed and PRaTful. I prefer 4 ohms. Made a very friendly pairing with Spendor Classic 1/2's.

Jack L's picture


Why not? Anything made in China will cost much less than made-in-original-country. "World-class" or not is another story.

China is a popular OEM for audios nowadays. So tempting for good profit in selling more quantities for lower pricing due to low cost built offshore. Business is business, no charity !

Jack L

Kevin Deal's picture

[[Edit: In case there are people reading this who don't know it: Kevin Deal (who wrote this comment) is CEO of Upscale Audio and Upscale Distribution; the former sells and the latter distributes PrimaLuna.--Jim Austin]]

PrimaLuna has been called things much greater than "World Class" The late, great Art Dudley said "I've never seen a better-built amp" with no qualification as to price.

We always tell people don't buy a damn thing without looking inside to make sure you are getting what you paid for and not fairy dust.

PrimaLuna is happy to compare side by side with any product at any price.

hootyboo's picture

Did the PrimaLuna have any difficulty driving the Martin Logans to realistic volume levels? After all, they are not the most efficient speakers, especially with the cone drivers below. I am asking because I drive mine with a Krell amp, which is fine, but I am curious to try tubes.

Kevin Deal's picture

[[Edit: In case there are people reading this who don't know it: Kevin Deal (who wrote this comment) is CEO of Upscale Audio and Upscale Distribution; the former sells and the latter distributes PrimaLuna.--Jim Austin]]

Rogier can comment, but I thought I might mention there is a guy named Pete Soderberg that worked for MartinLogan for something like 15 years, and he works at Upscale Audio now. Give him a call. Also Sean Smollen. He was a MartinLogan product trainer. They both work at Upscale now.

Jack L's picture

Hi Rogier

I fully agreed to what you heard about PL in triode mode. This sorta 'smoothing' effect has been the typical sonic downside of trioding pentode/tetriode in so many brandname triode-pentode power amps since day one decades back.

This is the historic conventional simple trioding topology employed by most most, if not all, brandname tube amps manufacturers worldwide. It is done by striping the screen grid (G2) to the anode of the pentode/tetrode in the power output stage, directly or indirectly using a serie low-ohm resistor.

Such simple trioding connection puts the screen grid operating the SAME voltage of the plate. This simple & no-cost triode-pentode mode serves a good selling feature for those triode fan lovers, like your truly.

Yet, sonically it makes the orginal punchy forceful sonics of pentode power amp sounds slow, dull like a leaking tire. That's exactly what you called "it takes the edge off" smoothing effect.

That being the case, why install this trioding feature onto the PrimaLuna amp then ? As a sales feature ignoring/without knowing such bad sounding triode effect ?????

Triode power tube always sounds much better than any pentode/tetrode: fast, transparent, silky & melodic. This is due to the signal transfer curves of a triode being linear vs kinked non-linear transfer curves of a pentode/tetrode, e.g. EL-34 etc. This is physics !!!! That's why so many music lovers like true triode music, including me, needless to say.

Despite your pre-review sales pitch for the Dutch designer, it does not change the sonic pitfall the conventional historic trioding pentrode topology he employed. Either he did not do auditioning of his PrimaLuna triode mode prototype enough or he simply took it for granted.

FYI, since I love true triode sound, I spent enough time to experiment the right topology for good triode sound out of a pentode/tetrode, e,g, EL-34 etc. Mainly for economy reason, as triodes, like 300E, 2A3 are very expensive to own , not-that-durable as pentodes & require much more costly complex circuitry.

Instead of the no-cost conventional 'no-brainer' trioding the pentode, the screen grid G2 is connected to the plate of the pentode, e.g. EL-34 etc, BUT with a stabilized potential difference betwen the screen grid & the plate of certain 'optimum' value.

So the trioded pentode is working like a triode BUT with a stablized potential difference between the plate & the screen grid G2.

The sonic improvement is realy rewarding: the pentode now sound like a true triode: silky, elegant & melodic like a true triode, yet retaining the transient, punchy & forceful sonic of a pentode. A sonic combination of both a triode & pentode !!!

My vintage Dynaco ST-70 has been ungraded to switchable triode/ultra-linear mode, using such "plate-G2 split potential' topology for many years now. No sweat! Yet I always set it to triode mode as it sounds soo much better than its factory orginal UL mode.

Listening is believing

Jack L

Kevin Deal's picture

Testify brother. But it's not for every person or every situation. That's why the Triode / Ultralinear switch is on the remote. I use triode at night because of what you said. The house becomes relaxed.

And by the way, females often prefer triode because they have more sensitive hearing than men do.