Innovative Adaptive AutoBias A PrimaLuna exclusive. If anybody tells you that they have auto bias, ask them precisely how. It’s most likely not true. As with all PrimaLuna amps, you never have to worry about biasing your amp ever again, and the need for matched tubes is eliminated. Just plug in a myriad of different tubes including EL34, KT88, or KT120 (the cage must be left off to use KT120) and AAB does the rest while improving sound quality. Tubes are constantly monitored and kept in their best operating range, reducing distortion by up to 50%
ALPS Blue Velvet volume control tracks better so a defined stereo image is established and doesn’t collapse as you raise and lower volume. And it will stay quiet, adhering to PrimaLuna’s guiding principle of “Built to last a lifetime”.
PTP-circuit. If the power transformer should overheat, this “Power Transformer Protection” circuit cuts primary power, allows the amp to cool down, then resets itself.
OTP-circuit. The “Output Transformer Protection” circuit protects the output transformers in the event of user error crossing speaker wires.
Simplified BTI-circuit. BTI stands for “Bad Tube Indicator.” If a power tube fails, BTI circuit then puts the amp into protection mode, and the green LED on the facteplate turns to red. With other brands, this may be when you have to break out the soldering iron to replace a plate resistor, and replace two or four tubes because your amp requires matched sets. With PrimaLuna, you just replace the bad tube (no matched tubes required), and turn the amp back on. No hassles, no headaches.
Soft-start circuit Extends component and tube life by powering up the amp gently every time you turn it on.
Custom designed output transformers Encapsulated low hum, wide bandwidth for great bass and extended highs. Designed by Marcel Croese and one of the most prestigious transformer designers in the USA .
Premium parts. Upgraded Solen capacitors made in France for beauty and fast recovery diodes to keep control when music gets busy.
Panel mounted ceramic tube sockets and rear jacks. Some brands will mount tube sockets or hook up jacks to a printed circuit board. As the product ages, these boards can crack by simply changing tubes or cables. All PrimaLuna products mount ceramic tube sockets to a stand off, and the rear panel jacks are secured directly the the chassis.
SmartWatts design. PrimaLuna’s true-value, low stress design philosophy. Many manufacturers fudge on their power ratings, claiming power that is mathematically impossible. Every seasoned tube owners knows that 20 watts from a tube amp is a ton of power. What is really important is that PrimaLuna runs their power tubes up to 40% easier that other manufacturers. You can tell easily by putting your hand on top of a PrimaLuna amp. They run cooler than others. There is no reason to run tubes at their jagged edge. Why do manufactures do it?
Point to point wiring. The ProLogue Classic is a work of art with internal construction you won’t find elsewhere. It takes more time to build, and is assembled by artisans, but it will last a lifetime.
Chassis made of finely finished heavy gauge steel, and five step automotive quality finish. Each coat hand rubbed and polished. Removable tube cage included no charge.
Toroidal power transformer for low hum, and a front end that is dead quiet.