- Written by Rick Schmidt
- Published on 14 December 2009
This amp has the same form factor as previous PrimaLuna products, basically a black square with the tubes neatly exposed and arranged in the front, optionally covered with a protective cage and a black or silver face plate. The KT88 tubes look awesome and imposing, tubes of these proportions give me a comforting feeling that my music is being given its proper due.
Front and center on the 'tube deck' is an indicator light that glows red when the amp is in Ultralinear Mode, green for Triode Mode. The modes can be switched via the remote, while music is playing. NEAT! As the manual describes, Ultralinear will play louder and exert more control over the speakers. Triode Mode is said to be 'Warmer on top and bottom, a little compressed with the midband more pronounced'. I found that I had to have that greater control of Ultralinear mode. More on that later.
One of the reasons I've been a solid state guy rather than a "tube roller" is the maintenance. I have always been under the impression that tubes are high maintenance. Relative to solid state anyway, which is no (or not very much) maintenance. I know this is part of the fun, but I just haven't gone there. Not yet anyway. PrimaLuna addresses part of the tube maintenance issue with their "Adaptive AutoBias" circuit. This circuit does away with the need for user adjustment of the grid bias voltage, and this keeps the tube signal output at its optimum. Another issue is that tubes can "blow" when you turn on a tube amp with the initial surge of current - called an inrush - that occurs. It's like when you sometimes turn on a room light, and the bulb filament flashes and burns out. Well, PrimaLuna has addressed this problem too. When you turn the amplifier on, the voltage is slowly ramped up to the final value, and this extends the life of the tubes significantly.
A phono stage can be added as an optonal feature for the DiaLogue Two, but it wasn't optional for me! An MM (no MC capability) phono stage with gain fixed at 42 dB and loading of 50 kOhm. This phono stage is 'the size of a large postage stamp'. Postage stamps are less and less necessary, while phono stages are now a hot item, so maybe soon that comparison will be flipped around.
I was rightly impressed with the remote for the Emotiva ERC-1 that I reviewed recently, but the remote for this PrimaLuna is the champ. Heavy, black brushed aluminum, just the right dimensions to fit into the well of your palm. The silver buttons have a great feel to them and best of all, the ends each have a heavy rubber band (think O-ring) that wraps the outside. When you set it down, it's resting on these bands. Quiet, nothing getting scratched. A nice touch.