POST Online Media Lite Edition


BHK Signature series amplifiers: Double everything

Dale Davies |
Available in both stereo and mono models, the BHK Signature series is unparalleled in its ability to render details formerly lost in the music.

Article continues below

BHK Signature is a hybrid design enjoying performance benefits from multiple design techniques including, a balanced differential vacuum tube input, balanced differential MOSFET power outputs, and separate, isolated, analog power supplies feeding each. The stereo Signature 250 produces 250 watts/per channel into an eight-Ohm loudspeaker, 500 watts/channel into four-Ohms, and stable into 2-Ohms; enough power to satisfy even the hungriest of loads.

The Mono Signature 300 doubles the output current with half the impedance of the stereo model. Each Mono Signature produces 300 watts into an eight-Ohm loudspeaker, 600 watts into four-Ohms, and 1000 watts into 2-Ohms. But more than just doubling the current, the BHK Signature 300 also doubles every internal component of the 250 into one: double tubes, double power supplies, transistors, capacitors and resistors. The BHK Signature 300 is a clear step above the stereo 250, on the order of 20% better.

The BHK Signature input features a classic triode vacuum tube in a modern configuration. Hand matched pairs of Russian Gold Lion 6922s are self-biased with constant current and high voltage, free of timing and phase distortion without the use of negative feedback. They provide the perfect interface between the delicate musical transitions output by the DAC or preamplifier, and are electrically isolated from the BHK power output stage which is connected to the loudspeaker.

MOSFETs handle power without the additional circuitry needed by tube power amplifiers, and they sound better than tubes or their solid state alternatives, bipolar transistors. The BHK Signature has two power transformers, one for the vacuum tube input stage, the other for the MOSFET power output stage. Each passive component is hand selected to provide the cleanest path possible. PRP resistors, film and foil Rel Caps, and the finest sounding parts possible are hand soldered onto BHKs circuit boards.

What to read next

Triangle, pleasant loudspeaker surprise from France
Raven Audio Shadow Reference tube stereo amplifier
Huge heart of Naim Audio NAP 250 power amplifier