ProLogue Premium Stereo Amplifier

Incorporating the best electronic elements of the original ProLogue Four and Five, plus selected ground-breaking features from the more advanced DiaLogue Series, the next generation ProLogue Premium Series is an engineering marvel — a single, stereo power amplifier that sets a new benchmark in high-performance audio with the following features:

• Innovative, new Adaptive AutoBias circuitry. By simply flipping a switch, users can re-calibrate the amplifier for optimum operation of EL34s or KT88s. Every ProLogue Premium Series amplifier can be ordered with either set of power tubes installed. And remember, this circuit continuously monitors and adjusts each tube to run in its sweet spot. No biasing—ever!
• Solen capacitors and fast-recovery diodes. Made in France, Solen caps give greater definition and more natural tonality, while fast-recovery diodes in the power supply provide greater control during complex musical passages.
• New output and power transformers. Modeled after those in the more advanced DiaLogue Series, these heavy-duty, high-efficiency transformers offer better control over challenging speaker loads, as well as increased detail and musicality.
• New front-end circuitry. Optimized to use two 12AU7 tubes per channel. With the improved transformers, produces lower distortion. The ProLogue Premium Series introduces four innovative circuits to protect the amp at every level:
• BTI-circuit. BTI stands for “Bad Tube Indicator.” On the chassis’ deck in front of each power tube, is a small LED that lights up if the tube goes bad. This circuit works hand-in-hand with the new Adaptive Auto-Bias circuit.
• 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 a massive tube failure or user error.
• +B relay. Replaces the plate fuse and works in conjunction with the OTP-circuit to protect the amp against tube failure. This method is less intrusive sonically and the relay resets itself once the faulty tube is replaced.
• Made by hand with the finest point-to-point wiring and quality equal to –or better than- any product you can buy at any price.
• SoftStart™ circuitry and advanced conservative design prevents shorts and extends the life of all critical components in the amp.
• Premium parts featuring: ceramic tube socket; Nichicon power supply capacitors; WBT-style solid core speaker terminals; ALPS Blue Velvet volume control; gold-plated RCA jacks; toroidal power transformer.
• Hand-rubbed, high-gloss finish with black or silver faceplate.

In addition, the ProLogue Premium Stereo Amplifier adopts the same specially designed phase-splitter and driver stage circuit as used in the original award-printing ProLogue Four and Five, resulting in zero negative feedback. This circuit provides a remarkably more natural presentation.