A power amplifier connects its reservoir of energy to the loudspeaker through a type of valve (solid state or vacuum tube) controlled by the input stage. If the input stage has done a good job of preserving music's subtle details, textures, timing and phase information, transferring it without loss to the power stage and eventually the loudspeakers is best handled by a tube-like solid state device known as a MOSFET.

Not all MOSFETs are the same, their differences characterized by their relationship with the input signal and the power supply driving them: N-types for the positive going signals, P-types for negative. N-types have lower distortion and perform better than P-types but N-channel-only amplifiers are rare. Using only N Channel MOSFETS in its output stage, the BHK Signature 600 monoblock amplifier produces a near-perfect balanced waveform without the degradation inherent in a complementary design. A pure design like that in the 600 output stage also requires unrestricted access to the power from the unit's massive 1.6KVA power transformer and its 300,000uF of energy reserves. Delivering this power from the supply to the output stage without restriction is not a trivial task. Wire and bus bar gauges must be massive. In the BHK Signature 600, gold plated solid copper bus bars tie to 2 gauge braided copper pathways connecting the high joule power supply with the demanding banks of MOSFET output devices. Music has rarely been reproduced with such effortlessness as in the BHK600.