The ProLogue Premium Series is the latest collection of tube electronics from PrimaLuna. The lineup includes an integrated amplifier—the subject of this review—also a preamp, a stereo amplifier, and a 70W monoblock. Like all PrimaLuna electronics ProLogue Premium has been designed in Germany Holland and manufactured in China. For PrimaLuna, the Premium Series becomes the tweener line geared to bridge the performance/feature gap between the entry-level ProLogue and the more advanced and costlier DiaLogue.
The ProLogue Premium integrated outputs 35Wpc. It is based on the EL34 output tube (or KT88s at no extra charge) (but KT88’s, 6L6GC, and a variety of others may be used) and runs exclusively in ultralinear mode. Visually it mirrors the clean, contemporary design of the DiaLogue with its massive transformers to the rear, EL34 output tubes center stage, and the 12AU7 valves nearest the front panel. Only two knobs—volume and input—bedeck the thick, narrow faceplate with a multi-color lamp indicating power and mute.
Performance has been significantly upgraded over the ProLogue with refreshed front-end circuitry optimized for the two 12AU7 tubes per channel that increases the synergy between the amp and a new optional moving-magnet phonostage. The new larger dual mono power and output transformers have been modeled after the DiaLogue Series and fine-tuned with additional windings for improved control over challenging speaker loads. The ProLogue Premium also adds a home-theater pass-through; a slender, full-function, anodized-aluminum remote is standard.
As with all PrimaLuna components, the ProLogue Premium Integrated incorporates a great deal of hand-assembly and point-to-point wiring. Anyone who has taken a peek under the hood (I have) can see these guys aren’t kidding when they holler about the premium parts they use. There are ceramic tube sockets, Solen and Nichicon capacitors, WBT-style solid-core speaker terminals with 4- and 8-ohm taps, and an ALPS Blue Velvet volume control. Very nice.
It wouldn’t be a PrimaLuna if it wasn’t easy to use. This has been a large part of PL’s mission from the beginning—demystifying the world of tubes and calming suspicions that valve electronics misbehave or are as capricious as your grandpa’s old lawnmower. Or, and most importantly, that tube electronics need to cost a huge amount of money to be sonically satisfying. To put these fears to rest once and for all, standard equipment is Adaptive Auto Bias (AAB), where a single switch allows users to re-calibrate the amp after making the switch from the EL-34s to KT-88s or back again. The circuit continuously monitors and adjusts each tube to run in its sweet spot. Rebiasing is a ritual that I, for one, won’t miss.
The ProLogue Premium Series has more levels of protection than the secret service. There’s a Bad Tube Indicator circuit that works in conjunction with the aforementioned AAB circuitry. If the tube goes bad a small LED lights up in front of the ailing valve and a relay opens, muting the amp and protecting it. When you replace the tube the relay closes automatically and the amplifier is back in operation. There’s also the Power Transformer Protection circuit, which, in the event of power-transformer overheating, cuts primary power until the amp cools off and then resets. Finally there’s the Output Transformer Protection circuit, which disables the output transformers in the event of a massive tube failure or (gasp) user error.
Sonically, the Pro-Prem does not have the rosy, euphonic colorations of traditional triode or SET tube varietals. Which for me is all to the good. There is a glimmer of romance and softness, but tonally it’s a thoroughly contemporary tube amp that walks a mostly neutral line yet still flavors and seasons the lowest level details of music with an almost tender delicacy and a resolution that I associate with the best of both worlds. There’s an inner light to images, an issue that I initially noted during Diana Krall’s performance of “A Case of You” from Live In Paris [Verve]. Her voice has a lilt, a buoyancy, that I rarely hear on amps in this price range. To me it’s the magic of dynamic nuance and low-level energy being retrieved—each note of her piano segueing into the next with silken harmonic continuity. And there is a low-level cue during Sinatra’s “Angel Eyes” that no other integrated amp has defined as well. It’s just a very soft rhythmic tap of the snare in the far right channel. In the past I’ve heard it sound unrecognizable as a snare, but the quiet rattles of this distinctive drum didn’t slip past the PL.
Does the ProLogue Premium like to swing? Does it ever. Just listen to “I Hope Gabriel Likes My Music” from Dick Hyman Swings All-Stars [Reference Recordings] to hear the combination of micro-dynamic and transient detail that illuminates timbre, cymbal textures, and broadens the range of expression imparted by the soloists—from the brassy explosive bloom of the trumpet to the sweet slippery glide of the clarinet to the grit and texture of the sax. Their unique voices counter and balance one another in a mix that is portrayed with great vigor by this amp.
Bass response is full, warm, and rounded, though not as controlled as that of a solid-state piece like the Perreaux Audiant 80i. However, PL bass is in its own way equally natural. During the “Gabriel” it conveys a ripeness and reverberant bloom to the opening tom-tom fill that makes the instrument sound remarkably vigorous and authentic. The bloom and expansiveness of the organ pedal points was also noteworthy during the Rutter Requiem, although the amp couldn’t quite resolve the fluttering tremolo detail from the deepest cues on the track “Lux Aeterna.”
At this juncture it’s fair to point out that in speaker matching there’s a narrower performance sweetspot for lower-powered amps. Any and all will lose a share of transient liveliness and flatten dynamics with speakers of lower sensitivity. However, it was love at first sight for the ProLogue Premium and the newest Vienna Acoustics Mozart Grand SE loudspeaker (about 90dB sensitivity), which I will be reviewing in a forthcoming issue.
During vocals there’s an almost subliminal presence shift that lightly lifts the upper register and harmonics of a vocal forward, almost akin to a note having some extra wind at its back. I felt that during “Angel Eyes” the ProLogue added a bit more air and glow to the top of Sinatra’s vocal. Like a spark of enhanced detail, in short bursts it was satisfying but at other moments it made me aware of the artifice. For a voice as familiar as Sinatra’s I didn’t feel that it allowed for the most seamless integration of the singer’s throat and chest resonance.
The most glorious aspect of the PL was its huge soundstage and cavernous sense of dimensionality. I thought you needed 3-D glasses for this kind of experience. As I listened to the somber “Landscape” movement from Vaughan Williams’ Antartica [Naxos], the soundstage broadened markedly, orchestral sections sweeping in like waves from deep in the venue. Delicate harp cues were cleanly reproduced, the ominous rumble from the timpani foreshadowing a leviathan organ about to engulf the orchestra. Truly stunning. I got the same impression of width and depth from a full chorus like the Turtle Creek Chorale in Rutter’s Requiem [Reference Recordings]. A character trait of the Premium ProLogue was an underlying surfeit of resonance and harmonic energy that seemed to swirl within the soundspace, providing a wetter acoustic rather than the tinder-dry micro-detail I often hear in transistor amps.
It’s hard to walk away from this amp without being mightily impressed. PrimaLuna’s latest effort goes to the heart of what the high end represents for many of us. Quality craftsmanship and great sonics? Of course. A fairly priced package? Sure. But, most importantly, the ProLogue Premium places the emphasis on ingredients that often elude more commonplace electronics—the liveliness and fluidity of the musical event. If you’ve been around as long as I have, then you know how hard it is to put a premium on that.
SPECS & PRICING
Power output: 35Wpc (40Wpc w/KT88s)
Inputs: Four RCA, one home-theater bypass
Dimensions: 14.5” x 8” x 15.5”
Weight: 46.3 lbs.
1042 N. Mountain Ave #B
Upland, CA 91786