Integrated Amplifiers

Having played with a number of PrimaLuna ProLogue products, I’m safe in saying that each and every one represents astonishing value because 1) they’re made in China, but 2) to European standards. They single-handedly established and provided credibility for the lower entry-level price point for rock-solid valve products, and showed that China was ready to compete with the rest of the world in hardware manufacture, if the proper structure was applied. With DiaLogue, PrimaLuna is attacking the next price point, with the same vigour.
   That in itself should be enough to make the DiaLogue Two a fascinating prospect for those with up to £2000 to spend on amplification. Provided it could pull off the same coup at £1999 as its predecessors did for under or around a grand, it would be a boon for the middle market. But then Prima Luna had to go and introduce Adaptive AutoBias, which positively encourages you to mess around.

CAN'T STOP MESSIN’
Not that this is the first amplifier to allow tube changes without manual re-biasing. Additionally, plenty of others have allowed users to swap tube types within a given category; AudioValve’s amps even let you mix tube types in the same channel, eg you can run a mix of KT88s, 6550s or EL34s in its bigger power amps.
   Be that as it may, PrimaLuna has made valve changing a feature of the DiaLogue Two, with proprietor Herman van den Dungen informing me that I could also use KT66s, KT77s, 6550s and a bunch of others in addition to the KT88s and EL34s supplied for review. Even better, and multiplying the possibilities, is the choice of triode or ultralinear operation (and I use italics to emphasise this) switchable with the remote control. So, not only do you get to swap valves, you get to A/B triode vs ultralinear from the listening seat, with a green/red LED telling you which mode is playing. And the differences are not subtle.
   This meant that the DiaLogue Two required four times the listening, as I had to audition both sets of valves, and in both modes. It almost begged four conclusions, because each mode sounded quite distinct from the others. And while experience will lead most of you to anticipate certain traits, eg added warmth in triode mode, choosing among the four possibilities is not that straightforward. Power, by the way, was never an issue with any of the four set-ups.
  If there’s any consolation should this plethora of choices overwhelm you, the triode vs ultralinear element is less difficult to deal with than one tube against another. The ease with which you can flick from triode to ultralinear – which you will do with much regularity when you discover how each deals with different recordings – makes for a perfect and instantaneous selection process. But let me also say this: triode vs ultralinear is just as empowering a choice as one valve against another. PrimaLuna really is letting you tune this to your heart’s delight.

MIXING 'N' MATCHING
So let me spare you some of the suspense: although I used this amp with LS3/5As and PMC DB1i speakers, the majority of my listening involved the Sonus faber Cremona Auditor Elipsa. And with that loudspeaker, the KT88s certainly had the edge over the EL34s: greater coherence, command and force. Conversely, I preferred the EL34s when using the LS3/5As, and in ultralinear mode: this choice tightened up the bass, added some mass and left the vocals intact.
   With either valve in triode mode through the LS3/5As, the midband grew too warm and almost (dare I say it?) gooey. Which is fine if you think Joss Stone should sound like Elaine Paige.
   Triode-vs-ultralinear challenges were more music-dependent rather than speaker-dependent. With hard rock, louder material, punchy brass, I opted for ultralinear. With fragile material, prominent vocals, acoustic strings, triode was preferred. This was consistent from speaker to speaker and valve to valve.
   So, please accept for the rest of this assessment that I stayed with the KT88s, flicking between triode and ultralinear as the music required. What needed aural detective work was finding out the intrinsic character of the amp regardless of valve choice or mode. And it genuinely sounds, blatantly, like a more robust yet more sophisticated Prologue. Which is how it should sound.

RICH YET NATURAL
Fed some analogue from a fine US mono LP of Connie Francis Sings Jewish Favorites, the PrimaLuna delivered a flood of schmaltz that would render even Ahmadinejad philo-semitic. Francis’ vocals always were a stunning balancing act: one track, emotional in the extreme, yet never sailing near the absurd bathos of Piaf, the next so poppy she could make the Spice Girls sound like the Staples Singers. Regardless of tube or setting, the PrimaLuna possesses a rich yet natural midband ideal for vocals of this calibre, and with detail that caresses every nuance. You want to put on some Toyah, just to savour the lisp, or Julie London to hear her breathe.
   Better still, and certainly augmented by the KT88, is openness – both its recreation of three-dimensional space and its clarity/transparency. True, this is not the most wide-open of valve amps – it’s certainly not as squeaky clean as a GRAAF or an Audio Research – but neither is it smudged. 

VERDICT
And now PrimaLuna joins the big boys. The value is still incredible, but performance, build and styling (the world’s best valve cage!) take things up a notch. More than that, this amp makes hi-fi fun again, especially if you get a kick out of valve swapping. PrimaLuna for grown-ups, with added refinement, grunt, detail, and transparency. Yummy.

Originally published in the July 2008 issue