PrimaLuna DiaLogue Premium HP power amplifier Review

The rest of the gang

Associated equipment for this review included my Rogue Audio 99 Super Magnum preamplifier, AAD 2001 (nominal 8 ohms, 86 dB) loudspeakers on custom stands, OppO DVD 981 player used as transport, Asus laptop (fitted with JRiver 20 media player), Audio Sensibility interconnects, digital and speaker cables, all with either OCC copper or silver wiring. Power cords used are Triode Wire Labs and Sjorn audio. Towards the completion of this review I substituted my AAD 2001 with the recently arrived Fritz Carbon 7 SE stand-mount loudspeakers (review forthcoming).

PrimaLuna DiaLogue Premium HP power amplifier Review

I used three different DACs for this review: Teac UD-501, Eastern Electric MiniMax, and iFi Micro iDSD–which I bought immediately after my recent three part review of some of their other components. I listened to a large variety of music using standard Redbook CDs and audio files, as well as some high-resolution PCM and DSD files on my laptop. The Teac UD-501 and iFi-audio Micro iDSD DACs are highly capable performers with DSD files. The rest of the system, including the Dialogue Premium HP amplifier, was able to distinguish even slight tonal differences when assessing the sound of the various DACs. Although sonic differences were small among them, I ended up using the Micro iDSD for the bulk of my listening which I favored slightly above the other two DACs.

EL34 midrange magic-Hark, the angels sing

After making sure the EL34 and KT88/KT120 optimum bias switch (located on the right side of the PrimaLuna DiaLogue Premium HP) was in the correct EL34 position I proceeded to start several long listening sessions. According to the manual, no harm is done even if the optimum bias is set for the wrong output tube, but I wanted the optimum bias anyway.

The Dialogue Premium HP stock 12AU7 and EL34 output tubes are quite competent, certainly much better sounding than Chinese manufacture of say, ten years ago. In either triode (green led) or ultralinear (red led) mode, tonal balance is basically neutral, with triode operation presenting an overall slightly warmer sound and producing slightly less gain-my educated guess is about 3dB lower. Since I prefer a slightly warmer sound in general, I listened mostly in the triode mode during the audition, with either EL34 or KT120 output. I must say that a few recordings sounded better in ultralinear mode, but I enjoyed many more recordings in triode operation.

With the DiaLogue Premium HP’s ability to operate either in triode or ultralinear mode, as well as the ability to substitute many types of output tubes, it is like buying several amplifiers for the price of one. You know I’m always looking for value and the DiaLogue Premium HP is a prime example.

Imaging is well focused with very good width and depth. The PrimaLuna DiaLogue Premium HP’s dynamic range compares favorably to higher power tube and solid state amplifiers, which lower power units simply cannot match. There’s excellent transient speed on rhythmic recordings, which had my head bobbing and my foot tapping multiple times. I couldn’t detect undue brightness or harshness in the treble region–with strings, cymbals, or sopranos–in fact; high notes are refined and smooth with excellent detail. Usually, tube amplifiers fall far short in the bass region when compared with solid state, digital or even hybrid amplifiers. Bass notes from many tube amplifiers are generally flabby and ill-defined. I can say the PrimaLuna DiaLogue Premium HP produces exceptional bass notes, almost comparable to its solid state brethren, with great articulation and tightness. What I like most about the EL34s is the way the midrange is produced, with an alluring delicacy that captures my emotion and holds it firmly throughout many listening sessions.

A good example of that midrange magic is an album which has now become a modern day classic: Joni Mitchell’s Blue. On the tracks “River” and “Blue,” Joni’s controlled use of vibrato is produced accurately and gives her singing an ethereal, other-worldly quality. The PrimaLuna DiaLogue Premium HP provides a hauntingly beautiful sound on this recording.

Holly Cole’s Don’t Smoke in Bed ably demonstrates the amp’s treble and bass capabilities. On “I Can See Clearly Now,” Holly’s voice is velvety smooth, without exhibiting unnatural harshness or emphatic sibilance as do some other amplifiers. On this track the acoustic bass notes are deep, taut and punchy with good pitch definition, while piano notes have proper organic harmonic overtones.

The DiaLogue Premium HP handles large scale, complex music very well, such as the superb performance of Modest Mussorgsky’s Pictures at an Exhibition (1959, London), with Ernest Ansermet conducting the L’Orchestre de la Suisse Romande. It is an early 1980s digital transfer to CD from the original analogue recording. It may not be included in the best digital conversion list, but the musical intent comes through clearly with the DP HP. Individual instrumental sections are spaced well between the speakers and instruments within each section are individualized. The horns and strings sound quite accurate, while deep notes have good weight and dynamic impact. The DP HP with EL34 output imparts an overall sweetness to this performance.

Complex tonal colors come to the fore on the Carpenters tribute album, If I Were A Carpenter, especially Cracker’s off-kilter cover of “Rainy Days and Mondays.” Lead singer David Lowery’s (of Camper Van Beethoven fame) slightly off-key and slow vocals matches perfectly with the dissonant cords of the lead guitar and the languid pace of the backup chorus. This strange but beautiful–if you like weird– arrangement is captured very well with the Rogue Audio/PL HP/AAD 2001 combination.

To get a sense of rhythm and pace, I played the Hollis Brown band album, Ride On The Train. The title track is a good ole rockin’ n’ rollin’ song; with the band’s percussive duo of bass player and drummer providing a rhythmic and hypnotic beat like a train locomotive. The PrimaLuna DiaLogue Premium HP delivers wonderful PRaT on this song.