The DiaLogue tube amplifiers from PrimaLuna have, at their heart, a clever idea of their own: an output circuit that is user-switchable between triode operation, in which the screen grid of a tetrode or pentode power tube is defeated by means of connection to the tube's anode; and Ultralinear operation, in which the screen grid of a tetrode or pentode carries a portion of the AC music signal, supplied by a tap on…
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The road to hell is paved with good inventions: clever ideas that appear, in hindsight, motivated more by a desire to sell clever ideas than to make musically superior products.
A couple of notes regarding the making of loudspeaker connections: According to Kevin Deal, the DiaLogue Premium does not invert absolute signal polarity. I listened for that anyway, and found that, for whatever reason—perhaps nothing more than my choices of music?—this was one of those amplifiers through which changes in polarity were exceedingly difficult to hear. I also experimented with different loudspeaker-output taps. The DiaLogue Premium offers separate terminals for 4, 8, and 16 ohms; although I relied on the 16-ohm terminals for my 16-ohm Altecs, their sound from the 8-ohm taps…
Sidebar 1: Specifications
Description: Push-pull stereo tube amplifier. Tube complement: six 12AU7, four EL34, KT88, or KT120. Output power: 25Wpc (14dBW) in Triode mode, 42Wpc (16.2dBW) in Ultralinear mode, with standard EL34 power tubes (see text). Frequency range: 12Hz–75kHz. Input sensitivity for maximum power: 880mV. Input impedance: 100k ohms. Output impedances: 4, 8, 16 ohms. Signal/noise ratio: 94dB, unweighted. Total harmonic distortion: <0.1%.
Dimensions: 15.4" (395mm) W by 8.3" (210mm) H by 16" (410mm) D. Weight: 63.8 lbs (29kg).
Serial number of unit reviewed:…
Sidebar 2: Associated Equipment
Analog Sources: Garrard 301, Thorens TD 124 turntables; EMT 997, Thomas Schick tonearms; EMT OFD 25 & OFD 65, TSD 15 70th Anniversary pickup heads.
Digital Sources: Wavelength Proton, AudioQuest DragonFly USB D/A converters; Apple iMac G5 computer running Apple iTunes v.11.0, Decibel v.1.2.11 playback softwares; Sony SCD-777ES SACD/CD player.
Preamplification: Hommage T2 step-up transformer, Shindo Laboratory Vosne-Romanee & Masseto preamplifiers.
Power Amplifiers: Shindo Laboratory Corton-Charlemagne & Cortese, Fi 421A.
…
Sidebar 3: Measurements
I measured the PrimaLuna DiaLogue Premium's performance using Stereophile's loan sample of the top-of-the-line Audio Precision SYS2722 system (see the January 2008 "As We See It" and www.ap.com). With two choices of output tube, each capable of being operated in Triode (green LED) or Ultralinear (red LED) mode, and with three output-transformer taps available, the DiaLogue Premium offers 12 different ways of being used, and is therefore 12 different amplifiers in one chassis. Because a full characterization of the behavior of each of those 12 amplifiers would…
I've long kept an eye on Michael Creek's loudspeakers (Epos) and electronics (Creek). He's always moving forward, with either updates of current designs or a revamp of an entire product line. And though I've found that many of his new-product ideas tend to feature evolutionary rather than revolutionary sonic improvements, I've found that they always represent excellent sound quality for the dollar in an increasingly competitive marketplace.
Of the five Epos speakers I've reviewed, I have a soft spot for the M5i bookshelf ($899/pair). Ever since I reviewed it in the February 2011 issue,…
The Elan 10's ability to render detailed, delicate transients reminded me of far more expensive speakers. With "Four," from Miles Davis's Workin' with the Miles Davis Quartet (CD, Prestige OJC-296), I followed every nuance of Philly Joe Jones's snare and cymbal technique and heard no trace of smearing or any artificial sharpness. And I loved the way the Epos presented a coherent rhythmic picture with well-recorded rock tracks. I'm normally not a fan of the Beatles' "middle" period, but with the Eposes I found myself analyzing the coherent integration of the guitars, bass, and Ringo's…
Sidebar 1: Specifications
Description: Two-way, stand-mounted, reflex-loaded loudspeaker. Drive-units: 1" (25mm) soft-dome tweeter, 5.85" (150mm) polypropylene-cone woofer. Crossover frequency: 3.2kHz. Frequency range: 51Hz–25kHz. Nominal impedance: 4 ohms. Sensitivity: 89dB/2.83V/m. Amplifier compatibility: 25–100W. Power handling: 100W, unclipped, speech and music.
Dimensions: 12.1" (310mm) H by 7.2" (185mm) W by 9.7" (245mm) D. Weight: 13.4 lbs (6.1kg).
Finishes: Cherry, Black Ash wood veneers.
Serial numbers of units reviewed: 0911-1070 A/B.
Price: $1000/pair. ST15…
Sidebar 2: Associated Equipment
Analog Sources: VPI TNT IV, Rega Planar 3 turntables; Immedia, Syrinx PU-3 tonearms; Koetsu Urushi, Clearaudio Virtuoso Wood cartridges.
Digital Sources: Lector CDP-7T, Creek Destiny CD players.
Preamplification: Vendetta Research SCP-2D, Creek Destiny phono stages; Audio Valve Eclipse line stage.
Power Amplifier: Audio Research Reference 75.
Integrated Amplifier: Creek Destiny.
Loudspeakers: Epos M5i & M16i, Dynaudio Excite X12.
Cables: Interconnect (all MIT): Magnum M3, MI-350 CVTwin Terminator, MI-330SG Terminator. Speaker:…
Sidebar 3: Measurements
I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Epos Elan 10's frequency response in the farfield, and an Earthworks QTC-40 for the nearfield responses. All the measurements were performed with the clothless "audiophile" grille fitted to the front baffle, which gives a smoothly curved contour in the vicinity of the drivers. The Elan 10's voltage sensitivity is specified as 89dB/2.83V/m; my estimate was very close, at 88.6dB(B)/2.83V/m, which is within the margin of experimental error. The impedance is specified as 4 ohms; my…