PrimaLuna ProLogue Premium line preamplifier

Everyone knows that world-class analog and digital sources are the bedrock of all fine audiophile systems. Everyone also knows that a happy relationship of amplifier, speakers, and room makes audiophiles smirk Aren't I lucky? Fewer among us are aware that the upper limit of sound quality an audio system can deliver will be established by whichever audio contraption we use to select our sources and adjust their volume.

A hi-fi system with too little gain or an impedance mismatch (especially at the interfaces of the selector switch and volume control) can sound dim or hesitant. A system with too much gain can sound jumpy, noisy, or unsubtle. In contrast, when our world-class sources feed a stable, non-fluctuating, high-impedance load, and the control unit's output is low enough in impedance and high enough in gain to stimulate the power amplifier to its full dynamic effect—then the system will sound as good as it can sound.

In my 100 years of life I have experimented with every possible preamplifier/control device: passive, active, digital, analog, tube, and solid-state. In the end, I usually prefer the liquid transparency and full-color jump factor of a well-engineered, tubed line stage.

You see, preamps don't have just their own sound—they affect the performance of everything that precedes and follows them.

Nowadays, I anchor my Bed-Stuy bunker system around my reference Pass Labs HPA-1 headphone amp and line stage ($3500), or the fresh transparency of one of these tubed preamps: Linear Tube Audio's microZOTL2.0 ($1100), the over-achieving Rogue Audio RP-1 ($1699), or the PrimaLuna ProLogue Premium ($2199). The Pass HPA-1 is the near-perfect rock star of the bunch, but of the three other preamps, the PrimaLuna ProLogue Premium delivers the most jump factor, seductive liquidity, and instrumental color. Which is why I must tell you about it.

Description
The PrimaLuna ProLogue Premium is basically an old-school, line-level tubed preamp, created in the Netherlands by Herman van den Dungen, and built in China to levels of quiet, durability, and sonic sophistication not possible in the 20th century.

The ProLogue Premium is built into the same type of blue-gray, subtle metal-flake, lacquer-on-steel case as the ProLogue Premium EL34 tubed power amplifier, which I reviewed in the November 2016 issue. That stereo amp weighs 46.3 lbs; surprisingly, this preamp weighs almost as much: 37.5 lbs. It's so heavy because it has two large, potted toroidal power transformers and two power-supply filter chokes, all sitting atop the chassis, hidden inside a vented box. Including its tube cage, the ProLogue measures 14.5" wide by 8" high by 15.5" deep.

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The ProLogue Premium's dual-mono heavy-duty-ness is enhanced by the use of one GZ34/5AR4 rectifier tube per channel. This design choice is extremely unusual—most tube amps forgo tube rectifiers, instead using solid-state diodes to save space and cost. In their defense, the amp manufacturers often say that solid-state rectifiers are quieter (they're not), or that they sound better (which I question), or that they do it to make their gear sound less like tubes and more like transistors (which is possible).

When a preamplifier does have a tube rectifier, it's usually a miniature 12X4 or 6X4 tube rated to draw 90 milliamperes of current—not the indestructible and organic-sounding, octal-base GZ34/5AR4, rated at 250mA. Each of the ProLogue Premium's 12AU7 twin-triode tubes draws only 20mA, so you can be sure that PrimaLuna is not using massively overspecced and costly octal tube rectifiers for durability alone—no way. I can assure you that PrimaLuna is using one high-current rectifier per channel because Herman van den Dungen believes it makes his $2199 preamp sound richer, faster, and less mechanical than other preamplifiers employing bevies of $1 rectifiers. Why else?

When I removed the ProLogue Premium's bottom plate, I was instantly impressed by the quality of parts and labor I saw. I've serviced countless tube amps, including some of the world's most expensive, and have never seen better-crafted point-to-point wiring or more intelligent layout. On their website, PrimaLuna makes a big deal about their tube sockets being bolted directly to their steel chassis. This is because it is a big deal—it makes their products more durable and trouble free than those of competitors who attach tube sockets directly to circuit boards. The latter strategy saves space, labor, and money, but every time the user removes or inserts a tube, there's a danger of irreparably damaging the board. Over time, that danger becomes a certainty.

Likewise with those volume controls and selector switches I was talking about. Many of the biggest high-end names use a $4 chip, a DS1666 Audio Digital Resistor, as a solid-state potentiometer to control volume; PrimaLuna uses a motorized Blue Velvet potentiometer, made by Alps in Japan, that costs at least ten times as much. Expensive, Japanese-made relays are used for the source-selector switch.

DuRoch polypropylene capacitors are featured in the power supply and signal path, while Solen polypropylene caps, made in France, are used at the outputs. Almost as impressive as all that are the Japanese-made Nichicon storage caps that proudly project from the ProLogue Premium's chassis top.

On the 7/16"-thick aluminum front panel are two symmetrically placed knobs: volume control on the left, input selector on the right. Centrally located between them is a handsome Off/Warming Up/On LED. The On/Off rocker switch is hidden away on the preamp's left side, just around the protruding edge of the front panel.

On the rear panel is a plethora of gold-plated RCA jacks for the inputs—CD, Tuner, Aux 1, Aux 2, HT (home theater)—and outputs: Tape Out, Out 1, Out 2. There's also a grounding post. A simple, slender, solid aluminum remote control is included.

Listening
Whenever I insert a new preamplifier or source component in the bunker system, the first thing I listen for is a change in the quantity or character of the musical energy projected between the loudspeakers. Is it denser? More textured? Weaker? Does it occupy more or less space in my room? Is it harder or softer? These are important traits to notice.

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That in mind, I began my auditions of the PrimaLuna ProLogue Premium with Iggy Pop singing a very stoned, slurry, after-hours take of "Jesus Loves the Stooges" (7" 45rpm EP, Bomp BEP-114). The song, by James Osterberg and James Williamson, appears to have been recorded with only two poorly positioned microphones: one on Iggy's upright piano, the other on his thick voice.

I was tracing this strange Iggy moment with a humble Ortofon 2M Black moving-magnet cartridge installed in a Jelco SA750B tonearm mounted an Analogueworks Zero turntable (review to come), driving a Tavish Design Adagio phono preamplifier, and instantly I recognized how the ProLogue Premium enhanced not only the music's force and strength, but also the space and scale of the sound. Momentum was excellent, and timbres were surprisingly real sounding; but it was the ProLogue Premium's listenability that made this crazy-ass recording so enjoyable. With my other preamps, "Jesus Loves the Stooges" sounds more ragged and fuzzy—more as if it's coming out of a boom box. With the PrimaLuna, it sounded all sweaty and solid, like Iggy onstage.

But as much as I love them, Stooges records are not always good for checking tonal beauty, imaging, or fundamental realisms. So I upped the beauty quotient a little and played Béla Bartók's Piano Concerto 1, in the 1977 recording by Maurizio Pollini with Claudio Abbado conducting the Chicago Symphony Orchestra (LP, Deutsche Grammophon 2530 901), on the not-so-humble analog rig of Palmer 2.5 turntable, Audio Origami PU-7 tonearm, and Mighty Cala Sound MCS TNT 15 moving-coil cartridge, with a Parasound Halo JC 3+ phono preamplifier and Bob's Devices CineMag 1131 step-up transformer. This world-class combo let the ProLogue Premium preamp and power amp strut their high-value stuff. The metal-flake blue team brought this spectacular DGG recording to a very high level of fine detail and lush lucidity.

The PrimaLuna tube combo produced the most mind-grabbing spatial contrasts: big and small, far and near were explicitly portrayed. Instrumental tones, staccato rhythms, and artistic intents were vividly exposed. Pollini plays with uncharacteristically wild attacks, and this system let me lose myself in them. Likewise, Abbado and the CSO explode this fantastic concerto—and the ProLogue Premiums let me savor every fast-moving fragment. (This record played so well with this group of components that it created, for me, an unforgettable moment.)

COMPANY INFO
Durob Audio BV
US: PrimaLuna USA
2058 Wright Avenue
La Verne, CA 91750
(909) 931-0219
ARTICLE CONTENTS

COMMENTS
tonykaz's picture

This is a remarkable review!

Every single reviewer seems to love this Brand of gear, probably for darn good reasons, none of the other reviewers have such intricate prose, not even Keven Deal.

The 12AU7 Glass Tubes are the actual amplifiers leading me to conclude that this review is a review of Prima Luna 12AU7s & the chassis mounted support circuits, which 'Begs" the question of how this chassis performs with the myriad of other 12AU7s that Mr. Deal specializes in providing. ( I understand that Upscale is the Biggest, Best and most reputable source for Audio Tubes in the entire USA, probably the entire World ).

Mr. Deal is also the Importer for PrimaLuna's sister Brand: Mystere, which seems to be nearly identical ( perhaps a bit older ) to PrimaLuna.

A descriptive essay on 'rolling' could be an accompanying Story that hardly anyone else is attempting, which I wouldn't bother to suggest except for Mr. HR's gift for words and phrases.

Mr. HR has the 'Ideal' test Laboratory to probe the mysteries of Valves and the skill to share his discoveries with the World, doesn't he?, his Editor might find this a useful concept to explore.

Glass tubes are not at all expensive compared to buying a whole new Amplifier, probably cheap compared to the range of Wires and other misc. stuff Audiophiles search out. It kinda opens a world of exploration for our intrepid group of "Seekers for Prefect Sound Reproduction". The headphone group have already begun exploring Tubes with their Schiit Valhalla, Lyr, Garage 1217, Bottlehead, Feliks headphone amps. Why not the Big Box guys? ( are headphones better resolvers than Box Speakers? )

a hopeful Tony in Michigan

ps. Every one of Herb Reichert's writings have left me wanting more, I'm hopeful of JA doubling Mr. HR's word budget, I'll double my Subscription!

malosuerte's picture

I have this pre matched with the Primaluna Dialogue Premium amp and I couldn't be happier. It may not be the most accurate, but it more than makes up for that in feeling. My Project xtension 10 feeds into an EAR 834, and the results are breathtaking in anything from Classical to Punk.

The PL offers tremendous bang for the buck, and this review encapsulates everything that makes it special.

As for rolling, I have really enjoyed playing with various tubes and the good people at upscale have really helped me fine tune things.

Again, great review.

mrkaic's picture

I don't understand how anyone can like this product. This is a preamp and should be accurate. The THD of 0.2% at 1V is way too large!

Correct me if I'm wrong, but we still strive for high fidelity, don't we?

tonykaz's picture

It's probably not too high a distortion, depending on your point of view.

Audiophile stuff is purchased on perceived Sound Quality, not on specs.

Still, I can easily understand your point of view. On principals, you can rely on SS stuff to present very good specs.

In practice, the Recording Engineers are pretty much 100% SS as are the Mixers and Mastering folks. However the performers will use a Tube Microphone Amp to improve their singing voice. ( they'll overlook distortions to get their "Sound" ).

If accuracy were of greatest importance, we consumers would migrate to loudspeakers like JBL 4311 Studio Monitors instead of the Great sounding loudspeakers we seem to own, doncha think? Gear would only need JA to do a measurement test for us to decide which Amp to buy, we wouldn't need or value subjective opinions of reviewers like HR ( why bother ? ).

I, for my part, have been a SS Amp guy since the mid 1980s when I discovered Electrocompainet. I now own a Schiit Asgard 2 ( Class A SS design ). I'm pleased by SS gear, I enjoy it's consistent performance but I've also heard the Schiit Valhalla 2 ( tube ) Amp/pre-amp, which I ( and a great number of fellow listeners ) felt had a much superior Sound Quality, it had a superb set of Russian Tubes. The down side of the Tube stuff is it's short life before needing another replacement set ( an ongoing cost problem ). So I've contented my self with the lesser ( but consistent ) performance of SS.

B.H.King, the famous electronics designer, says : he doesn't know or understand why Tubes sound good, they just do. ( I'm having to agree with him ).

There are some darn good sounding SS designs out there but be prepared to pay an "Arm & a Leg" for em, they don't come cheap anymore.

Funny how the Tube stuff is the Cheap stuff nowadays.

Tony in Michigan

mrkaic's picture

I actually like tube gear, but it has to be honest tube gear. In the old days manufacturers would strive to achieve the lowest technologically possible THD and IMD. That was true for both tube and SS gear. If you read old tube amp commercials/manuals, you see that they prided themselves on low distortion (and good specs in general). In the old days, good specs were perceived as good sound quality.

Modern audiophiles have forgotten all that, they just love "the sound of tubes". They think that sloppy sounding tube amps are the bees knees and that sound quality and specs are two different things. They are not. I don't know why we have regressed to this sorry state, but I have a few theories: (i) denial/denigration of science in the society at large; (ii) the domination of audio publications by individuals who have no engineering education, but a strong desire to be perceived as refined and relevant; (iii) the need by customers to feel special when buying gear (impossible if you have to admit that all competent amps sound the same); (iv) other, depending on how I feel at the moment :)).

Finally, as to your point: "Gear would only need JA to do a measurement test for us to decide which Amp to buy, we wouldn't need or value subjective opinions of reviewers like HR ( why bother ? )."

My point exactly, read the measurements, skip the rest -- subjective reviews are worthless.

ToeJam's picture

I enjoyed the review for all its glorious subjectivity and it compels me to consider a PL audition.

It is predictable, but never the less fascinating, that someone will in a public forum proclaim to be the arbiter of merit and truth. Worthless is my objective valuation of such proclamations.

mrkaic's picture

I stand for objective standards -- measurements, and science. That old school stuff that gave us the standard of living we enjoy today. :))

What we have in audio these days, is a sad case of emperor's new clothes. Too many individuals with little or no engineering education who "review" audio equipment and write soapy articles in trade magazines. It is BS on par with wine tasting.

Those who care about truth in audio should begin by reading the following: http://rationalwiki.org/wiki/Audio_woo

ToeJam's picture

Since you put it that way, I completely see it your way. You are rather convincing. So much so that I don't feel the need to follow the link you provided.

mrkaic's picture

I disagree with you about audio, but I like your sense of humor. Well done.

tonykaz's picture

Is there anything about Music that's Objective?

Nearly everything we humans do is based on Subjective.

We chose things we subjectively like and enjoy, don't we?

The entire music recording chain is based on making the music more appealing, subjectively.

We've had Scientific methods for about the last 500 of our 10,000 years of civilized history, we're new at it and were still learning.

Objectively, we could eat a Dog Food mix based on our nutritional needs and get by nicely, we don't need good tasting food, do we?

We could get by with only one Car Color, what good are all those color choices?, they're needless expense that don't add value. White tests best.

Women's fancy clothes and makeup are nonsense, we don't need that sort of thing, no matter what the testing shows. Lets have only one "approved" garment for women and get rid of all that Sizzle the Shopping Malls sell.

Fusion Jazz is a harmonic disaster, it's horrible and tests badly.

What on earth do we need Wine Tasting for, lets just have $5 Vodka to get our buzz. Booze tests results are among the worst, that stuff will kill .

More Dentists recommend Chesterfield Cigarettes, the MDs prefer Lucky Strikes, who's right? Lets do some testing and get to the bottom of all that.

An Objective person will look at our Subjective World and simply accept it.

A Neurotic person will look at our Subjective World and not like it one bit.

A Psychotic person will look at our Subjective World and see it differently each time.

Tony in Michigan

mrkaic's picture

Dear Tony,

the question is quite simple -- do audiophiles still want high fidelity audio equipment? Achieving good measured performance was the mainstay of audio industry during its "golden age". Then something happened and now audiophiles don't care about fidelity anymore, they prefer equipment that editorializes and is not necessarily faithful to the recorded music. I don't care if audiophiles like equipment that distorts, but such gear should not be called hi-fi.

As a paradoxical aside: the same audiophiles who prefer sloppy equipment, reject equalizers, filters, etc., because they want "as few things as possible in the signal path". Well, I hate to tell you, but using a sloppy/distorting (but subjectively preferred) amplifier is EXACTLY like using a nonlinear filter on your music and then pushing the filtered music through an accurate amplifier. [If you know enough math, you can actually write a piece of code, that will filter digital music to achieve this effect, e.g. the sound of tubes.] So "purist" audiophiles effectively like a lot of crap in the signal path, they are just not aware of it. :))

tonykaz's picture

I use an equalizer and understand that all stages of the Recording Process alter the original sound.

"Audiophiles" pursue gear that they enjoy the sound of, gives them status among their peers and probably a few other reasons. I owned and operated a High-End Salon ( Esoteric Audio in Farmington Frills, Mi. c.1985 ) I worked with Audiophiles on a daily basis. ( my wife refered to our cliental as the "Lunatic Fringe").

We at Esoteric stocked only outstanding sounding Loudspeakers that reviewers would pan in favor of their allegiances.

I was mostly a Turntable Arm Phono Cart. outfit, I carried nearly every brand and type of turntable in existence.

Audiophile itself is a Religion, a person needs to be a "True Believer" to go along with much of the rituals involved, especially among the Vinyl group ( in light of digital's outstanding performance abilities ), the Vinyl guys have to defend the ownership and purchase of $50 Vinyls, $15,000 playback gear and all the storage space required to maintain their Fossil Fuel based storage medium. I was a Vinyl guy.

I left the Audio Industry and returned to GM Corp., I'm a retired Manufacturing Trouble-shooter, an Analytical. Since 1985 I haven't maintained or owned a Home Audio System until I happened to encounter Tyll & Steve Gutenberg at a RMAF event of 2011. I subsequently bought and enjoy Sennhieser Headphones and Schiit Electronics. Now, I'm a digital guy.

I've been a "follower" of JA since I lived in England, hence I'm now a subscriber of his work at Stereophile, which is as good as Audio journalism gets or ever got.

As an Analytical, I take this distortion stuff with a grain of salt. I don't think we can actually hear distortion lower that 20%. I was at a Audio measurement seminar where a test equipment company demonstrated distortion in 5% increments, the audience couldn't hear or notice distortion until it reached the 25% level. This was an Eye-opener for me and my fellow Auto Industry types who design products on the basis of NVH ( noise, vibration, harshness ). Phew, chasing .1% distortion levels seems like a hoax.

As a Salon Owner, I would take Magnapan stuff in trade, I'd set it up with a Conrad-Johnson MV-45a and let em play music all day long, they'd be sold within a couple of days. The Conrad stuff wouldn't sell worth a shit but it was a magical combination. go figure!

I stocked the entire line of Conrad stuff and the ultra modest Audible Illusion Modulus Preamp, the Modulus sold like crazy from it's sonic attributes, the Conrad stuff collected dust.

I was an Electrocompaniet Dealer, it was the best sounding electronics I had or ever had or ever heard!!! I sold tons of Thiel Loudspeakers with the Electro stuff, but Audiophiles wouldn't touch the Electro because Harry Pierson of TAS didn't like the stuff.

I've had to accept that Audiophiles don't believe their own ears, they desperately need peer approval and Authority blessings from Reviewers.

Having said all the above, I've come to rely and even trust JA, Tyll and HR who seems to agonize over discoveries. These three seem to attract like minded searchers like Bob Katz and many others who make useful contributions to our "civilian" understandings of Audio reproduction.

We're going into a Whole new world of Music accessibility, I'm staying tuned to these lads so that I can keep pace without squandering time and funds on nonsense purchases. ( I'm an impulse buyer that thinks informed decisions are useful ).

I'm here to be informed!

My personal experience is that only a tiny fraction of High-end electronics is magical, I've owned and sold the best performing stuff, it can be either Tubes or Solid-state. Today, the SS stuff is outrageously expensive but if you carefully search out the great tubes ( Keven Deal ), then a modest amp can deliver outstanding musical experiences. What makes great sounding tubes sound so wonderful ????????

I simply accept.

Tony in Michigan

ps. the exception to pricy SS stuff is Schiit stuff.

mrkaic's picture

""Audiophiles" pursue gear that they enjoy the sound of, gives them status among their peers and probably a few other reasons."

Perfectly put! Thank you for this.

Best,

MM

ToeJam's picture

an Audiophile by that definition because I care very little about status amongst my peers. And I agree that measurements are useful. However, I don't care how something measures if I like it when I hear it. Thus, I like subjective opinions from experienced reviewers because it broadens my awareness of the market.

Anton's picture

Best 'Manufacturer's Comments' ever on this review.

Kevin Deal hit that ball out of the park.

His reason for high prices on Hi FI gear gives you perfect insight into a place where Kevin lives every day.

Kudos to him and Prima Luna.

Such a great review and comment on this that I gotta figure out where to go next with my system.