PrimaLuna DiaLogue Premium HP

Hardware Review

PrimaLuna DiaLogue Premium HP
Wednesday, November 26, 2014
power amplifier
René van Es

The latest PrimaLuna power amplifier is for anyone who wants to create serious volume levels in the listening room, René must be among them.
Last weekend we had some friends over for dinner, one of them is a music lover. The first thing he noticed was that I had amplifiers with (so many) tubes. He asked how old they are and told me they looked very well preserved for their age. When I told him this was the latest model and made some months ago he looked at me in disbelief. Why on earth would someone produce amplifiers with tubes, even more crazy: buy them! I could not convince him that it’s not the technology that counts but the results, so I turned on the system and played some music. Soon he asked me who the singer was and forgot all about the tubes.

The amplifiers are a pair of the latest PrimaLuna creations in the DiaLogue series, the Premium High Power amps. These were developed for demanding loudspeakers or people who like to play very loud. PrimaLuna didn’t want to risk its reputation by increasing supply voltage in order to squeeze out extra power, instead they developed a power amp with the twice the output tubes and heavier transformers. The power rating is a very conservative 72 Watts in ultra-linear mode with EL34 tubes in stereo, or a maximum of 175 Watts with eight KT120 tubes in mono. Next to sound quality reliability is the key word in the PrimaLuna vocabulary. Take a look inside the amp and you see point to point wiring, heavy duty circuit boards and components sourced from Takman (resistors) and SCR (foil caps). On the outside the attention to detail can be seen in the way that the logos on the tubes are printed to face the same direction, the heavy chassis is painted in shiny black with a black or silver faceplate and a cover protects the tubes. All connections are made at the back, with speaker taps of 4, 8 and 16 Ohm in stereo operation or 2, 4 and 8 in mono mode. On the left is a power switch, on the right a bias switch for EL34 or KT88, 120 or 150 tubes. A remote control switches the amp from ultra-linear to triode operation. The faceplate contains the remote control eye and three LEDs that indicate operational mode and warm-up/power.

Bad (ass) tubes
PrimaLuna uses six 12AU7 tubes for the preamp circuit and driver to reduce distortion, increase bandwidth and enhance dynamics. The adaptive auto bias board inside the amplifier reduces power tube distortion by at least 50%, it also takes care that the tubes are optimally biased whatever their age. If a tube fails, an LED next to the tube will light. In my case this revealed faulty KT120, tube replacement was therefore simple and straightforward. Further protection for misuse or over heating is managed by the Bad Tube Indicator circuits, which simply shut down power to the faulty tube. Power Transformer Protection cuts off the mains power in case of overheating and Output Transformer Protection saves the devices in case of a mistake made with the loudspeaker cabling. A relay replaces the oft used fuse, so there’s no need to open the case if a bad tube trips the protection circuits. Last but not least an AH! Offset Killer eliminates the last traces of transformer hum on bad mains power sources. All of which are explained in detail on the PrimaLuna site if you want to go deeper.

The one feature this amp lacks is XLR inputs, I like to run my preamplifier fully balanced from input to output but couldn’t do that here. Over the review period I switched between triode and ultra-linear modes, but most of the listening was done in the latter state, I find that it’s more dynamic, more expressive and closer to live performance with my PMC fact.12 speakers. Of course no one has to agree with me and readers may prefer the soft and intimate sound of triode operation. In triode mode power is reduced by almost 50% (see specs below). With enough power on hand comparison was easy enough by just pressing the one button on the remote control and turning the volume up or down. With every PrimaLuna I have owned or reviewed I preferred the ultra-linear operation for most loudspeaker types.

I used DiaLogue Premium HP as a stereo amplifier loaded with eight EL34 tubes, eight KT120 tubes and often in monoblock configuration. The standard version is stereo with EL34 so this is where I will start. Listening to the wonderful Melody Gardot it isn’t hard to notice that the EL34 is the ‘midrange tube’. I love its presentation of voices and rounded top end, but it lacks some power and grip in the lower octaves. This is not often a problem when used with smaller loudspeakers, but a transmission line like my fact.12 goes deep enough to exploit all qualities. The singer’s voice stands out before the band, tender and intriguing, kept firmly in place between the loudspeakers and exactly the right size. A very human Melody appears before me. Brushed cymbals are close to the back wall, brass instruments are further forward while the piano is rock steady. The orchestra surrounds the singer. The midrange is forward, ever so sweet but with bite. The Fever duet between Ray Charles and Natalie Cole shows these capabilities too. Natalie should be leading the singing and she does so without question. The bass in the background is nicely defined and not exaggerated. On the same CD (Genius Loves Company) there’s a duet with Johnny Mathis and Ray. These male voices are presented extremely well, powerful and realistic, and it’s easy to understand each and every word. Nothing is muffled or masked by the orchestra, which tries hard to attract your attention.

 

 

More dynamics
The Guitar Trio by Paco de Lucia, Al Di Meola and John McLauchlin plays Manhã de Carnaval, which shows the differences between the three guitars and the style of playing from each musician. Notes are clear and warm, the amps clearly separating the strings from the body of the instrument. I would love a bit more dynamics, but that's where the KT120s come in. When guitar is played so well I feel the need to try solo piano. The French Alexandre Tharaud plays works by Erik Satie (Avant Dernières Pensées) starting with Gnossienne No.1 followed by Petite Ouverture A Danser, tracks that offer both soft notes as well as more dynamically demanding ones. This is no problem for the PrimaLuna because it has so much power on tap. Naturalness is again a strong point of the amplifier, revealing just how majestic a grand piano can be when the combination of source, amplification, loudspeakers and room acoustics allow. Moving on to some classical work I cannot surpass Janine Jansen’s playing of The Four Seasons by Vivaldi on a very fine recording from 2004. The violin takes the lead for each part, with backup from the other instruments spread well beyond the outer flanks of the loudspeakers. This forms a stage that’s big enough to be real, yet at the same time the performance is intimate and close to the listener. Not in your face I hasten to add, but you are definitely not sitting in the back row. The bass is strong enough, the organ’s always there, the light tones of the harpsichord never get lost and the cello’s ‘whooshing’ all the time.

I have tubes
This seems like a good time to switch over to the a DiaLogue fitted with eight KT120 tubes. After a half hour warm up I continue to play the Janine Jansen CD. The beautiful midrange of the EL34 turns into a less expressive one but a lot more has changed as well. The whole presentation is far more powerful, bass is not louder but it is stronger than before, with more grip. The stereo image is wider, reaching not only beyond the cabinet sides but out to the adjacent walls. Solo violin moves forward, the orchestra backwards. The presentation is livelier and the small loss of the extreme beauty of the EL34 midrange is soon forgotten. This is my favourite tube nowadays for power delivery. Although violin might be a bit more aggressive, a bit rougher, the sum of the parts comes closer to a live performance. Playing the Isabelle Boulay CD Merci Serge Reggiani the guitar is very powerful, while the voice of Isabelle comes to life. The extra power of the tube, stretching over the whole frequency range, adds to the way the already lifelike DiaLogue behaves. The PrimaLuna is not a typical tube amp, the PrimaLuna is simply a very good amplifier period. I have had other tube based amps at home that really shouted “I have tubes” and solid state amps that tried to sound that way, the PrimaLuna is a neutral device in between these extremes. Delivering what has been sent by the source, as steady as solid state, with tube dynamics and expression.

Next on my list is Dame Kiri Te Kanawa singing She Is Far From The Land from the CD Kiri, this shows that classical voices are as good as others on this system. Another track from the same CD that usually drives me crazy on poor systems because it’s demanding, is handled with so much ease that even I won’t turn down the volume. And speaking of volume I have this nice Filur track (You and I (Trentmøller remix), The Trentmøller Chronicles) on a Dali promo CD, full of thumping bass, mystic sounds from left to right and back and then the voice of Pernil Rosendahl enters my listening room. When this track is played really loud the loudspeakers ‘disappear’ with a decent amplifier behind them. The bass needs to be tight, fast and controlled. One PrimaLuna HP amp delivers, but how about two in mono configuration, adding an extra four power tubes on each of the stereo channels. Do we really need the extra power or are we just after luxury?

Club René
When both amps are warmed up it is obvious that the character of the sound did not change, nor did the soundstage, it is more the impact and realism that increases with the extra power. The PMC speakers, always eager for power, are happy to turn my living room into a club. This added drama was also welcome when I used my stereo system for home cinema, to play the soundtracks of movies or TV series. The extra punch in the lower registers added to the special effects rumbling through the room. Nevertheless, the extra power does not ruin the subtlety of the DiaLogues. Songbird from Eva Cassidy and Farewell Farewell by Mary Black stay intimate, clear and detailed as should be. This is why I used two amps in monoblock operation for most of this review. Often with lesser amplifiers extra power takes away the tiny sounds that makes music engaging, not so with the PrimaLuna. They sound small when required and deliver force if you push them. I have no idea about the limits since I simply never reached them.

So with the volume at a sensible level I enjoy some more Mary Black songs including Katie, a song that makes the Irish sentimental when it’s played live. I love the way the voice is handled, so pure, uncoloured, standing out from the band, while at the same time the band is always part of the performance. Time to end with Paul Stephenson’s CD These days, the PrimaLunas let Paul’s warm and powerful voice reach down deep. The acoustics instruments that surround him appreciate both the KT120 tubes and the second amplifier. Maybe better systems exist (I admit they do) but not in this price range I am afraid. Otherwise why would I keep the review examples for such a long time and leave my own amplifier to gather dust?

An investment in pleasure
One thing is for sure, a PrimaLuna amplifier will never disappoint, whether it’s an integrated, a preamp or a power amplifier. I have reviewed enough of them to be convinced of their reliability, ease of use and universal usefulness. Build quality is excellent while tube life is extended because PrimaLuna never pushes tubes or parts too hard. The DiaLogue Premium High Power amps pull you into the performance, with an octet of EL34 tubes you get the romance, replace them with KT120 and you gain in dramatics, power and control with most of the romance. If you want a more rounded sound, use triode mode or if you crave more dynamics stick with ultra-linear. It is up to the listener what tube or mode to choose, with a simple flip of a switch. Do you want even more power because your loudspeakers demand it, take two of these amps and turn them into monoblocks. These amplifiers are as easy to handle as any solid state device, just as reliable or even more so, sound the same or better and offer outstanding value for money. Do not buy them for being tube amps, do not turn your back on them for being tube amps either, buy them to enjoy your music collection over and over again. A PrimaLuna is not just a flirtation, it is an investment in pleasure.

Specifications: 

Output Stereo:
72 watts x 2 EL34 & KT88 (ultra-linear)
85 watts x 2 KT120 (ultra-linear)
42 watts x 2 EL34 & KT88 (triode)
45 watts x 2 KT120 (triode)

Output Mono:
148 watts EL34 & KT88 (ultra-linear)
175 watts KT120 (ultra-linear)
85 watts EL34 (triode
89 watts KT88 (triode)
94 watts KT120 (triode)
Freq. Response (+/- 1dB): 9Hz-59kHz (stereo), 8Hz-69kHz (mono)
THD (1W/1kHz): < 0.1% (stereo), < 0.1% (mono)
S/N Ratio: 99 dB (stereo), 105 dB (mono)
Input Sensitivity: 1.2V (stereo), 1.1V (mono)
Input Impedance: 100k Ohm
Power Consumption: 280 watts
Dimensions (WxHxD): 38.1 x 21 x 36cm (15" x 8.3 " x 14.2")
Weight: 30kg (66.3 lbs)
Analogue inputs: RCA
Outputs: 4, 8 , & 16 Ohm output taps (stereo), 2, 4, & 8 Ohm output taps (mono)
Tube Compliment: 6x 12AU7, 8x EL34, also available KT88 or KT120 tubes

Price: 
EL34 stereo: £3598
EL34 monoblock pair: £6796
Manufacturer Details: 

Durob Audio BV
www.primaluna.nl

Distributor Details: 

Absolute Sounds
T +44 (0)20 89713909
www.absolutesounds.com