Description

The Pathos Adrenalin Monoblock Power Amplifier represents the point of arrival for Pathos Acoustics’ InPol (“Inseguitore Pompa Lineare,” or Linear Pump Follower) concept — the patented circuit topology that has defined the company’s sound since its introduction. Where Pathos’ integrated amplifiers apply InPol technology within a single chassis, the Adrenalin dedicates an entire monoblock to the pursuit, resulting in what the company describes as “an iron fist concealed in a velvet glove”: a tube amplifier with an exceptionally sensitive, refined timbre, combined with astonishing output capability.

Voltage amplification is handled by a unitary-gain power buffer controlled by a tube stage using three double triodes — two ECC83/12AX7 valves and one 6H30. The first stage generates voltage amplification, while the second acts as a buffer with a common anode configuration alongside the 6H30, driving two groups of power MOSFETs. Each Adrenalin monoblock is built from two power stages connected in a double-InPol configuration, functioning intrinsically in Class A throughout, and delivering 200W into an 8Ω load without any global negative feedback in the signal path.

This InPol architecture allows the theoretical output of a pure Class-A design to increase by 25% to 50% over conventional topologies, while maintaining the low output impedance essential to a strong damping factor — a benefit further enhanced by the double-InPol configuration used here. Because the InPol current stage adds drive current without altering the voltage signal already shaped by the tube stage, the Adrenalin preserves the full quality, purity, and harmonic content of the original tube signal all the way to the loudspeaker terminals.

Pathos spared no expense on the amplifier’s power delivery, employing an optimized inductive/capacitive switching power supply engineered to perfectly filter the electrical current feeding both power stages — critical for an amplifier operating at this level of output and linearity. The result, as Pathos describes it, is a very powerful, extremely linear amplifier free of the compromises that typically come with high-output Class-A designs.

Like every Pathos product, the Adrenalin is designed and hand-built in Vicenza, Italy. Each monoblock is sold individually, allowing systems to be built as stereo pairs or scaled further for bi-amping and multi-channel configurations.