- Written by John E. Johnson, Jr.
- Published on 22 November 2010
- PrimaLuna ProLogue Premium Stereo Tube Preamplifier
- Page 2: Design of the PrimaLuna ProLogue Premium Preamplifier
- Page 3: The PrimaLuna ProLogue Premium Preamplifier In Use
- Page 4: The PrimaLuna ProLogue Premium Preamplifier On the Bench
- Page 5: Conclusions About the PrimaLuna ProLogue Premium Preamplifier
- All Pages
I tested the ProLogue Premium with the Mysterè pa21 tube power amplifier that we reviewed a few months ago and I still had on hand. The pa21 outputs 55 watts per channel. The source was an OPPO BDP-83SE/NuForce universal Blu-ray player, and I used the analog outputs from the player to the inputs on the ProLogue. Speakers were Carver Mark IV's, and cables were Emotiva and Legenburg.
My own reference systems consist of tube preamplifiers and solid state power amplifiers (or hybrid tube/solid state power amplifiers). I like the tube sound, but I want the power that is only available with solid state power amplifiers. For example, my McIntosh MC1201's output 1,200 watts RMS into 8 ohms. This gives me the dynamic range that I want when listening to classical symphonies at full tilt.
Nevertheless, a full tube setup has its advantages, namely, that all of the sound is tube, which tends to have even order harmonics, which are euphonic. Critics of tubeophiles who say they like the even order harmonic sound state that it is not in the recording, but just something added on top that is artificial. Well, it boils down to this: you don't have the option of "no distortion". All amplifiers produce distortion. What you get to choose is which type of distortion. So, I choose the even order type of distortion that tubes produce, for the preamplifier, and I accept the odd order distortion that I get in my power amplifiers because I need that power.
So, 55 watts doesn't blow out the walls, but in fact, most of the time, we listen at a level of less than 10 watts. It's the cannon shots in The 1812 Overture that won't be conveyed in all their glory, but in general, 55 watts is enough for most listening.
The ProLogue was a perfect match with the pa21, producing lush, warm sound that put me into deep relaxation. There is a smoothness to an all-tube hi-fi system that cannot be matched when there is solid state anywhere in the signal path.
This Telarc SACD of some of Debussy's compositions is quite beautiful, and the music was conveyed with convincing detail and dynamics, nothwithstanding the power limitations. The sound was neutral, but kept its triode foundation. The symphonic poetry as read by the the Cincinnati orchestra definitely increased the flow of serotonin throughout my brain, allowing me to listen, without trying.
Female voices are beautiful enough without seond order harmonics (only a geek would say something like that), but through triodes . . . gorgeous. Sutton's voice soothed my long day into a restful relaxation in the evening sitting by the window. No overly sibilant words to the music. Just clean, detailed, silk.
In this Telarc recording of the Los Angeles Guitar Quartet, a.k.a., LAGQ, the musicians honor famous guitarists of the past, including Jimi Hendrix and Frank Zappa. Now, if an amplifier had the slightest harshness, the twang of the guitars playing music of those artists from the 1960's would be like broken glass. But that didn't happen here. It was like crystal lightly tapped with your finger.
Brass instruments are another area of concern with an amplifier that produces too much odd order harmonics. Since the PrimaLuna ProLogue Premium preamp doesn't do that, the brass - in this case, French horns - were smooth, yet delivering the slight edge that horns tend to have.
I also played a lot of Vivaldi chamber music, you know, string quartets and such. I don't remember which track on the third disc where I fell asleep. Ah, tubes deliver such peace.