Pathos InPol Heritage MkII Tube Hybrid Integrated Amplifier

A pure class-A ECC803S input stage pairs with Pathos' double INPOL technology offering high output with exceptional damping

White/Black and White/Padouk finishes are a special order. Approximate lead-time 6-8 weeks.

With the Mk II version of this celebrated amp, Pathos has doubled the power section turning it into a dual mono unit. Another heat sink increases the radiating surface and allows better placement of the MOSFETs. Thanks to these improvements, Pathos got better dynamics out of the amp, especially in the low frequencies.

Think of the directness of SET with the control and damping of solid state. Pathos' patented and unique InPol technology allows the tube input stage to effectively drive your speakers with no further amplification. A dual InPol circuit delivers the low impedance and high current needed for a high damping factor, allowing for immense control over your loudspeaker drivers.

InPol (Inseguitore Pompa Lineare or Linear Pump Follower) is a Pathos patented system.  that allows for much greater output in pure class-A. This fully balanced circuit design uses a single solid-state component in follower configuration, with a both a high current and high voltage gain. 

What is InPol?

When you listen to music, you’re not just hearing notes—you’re experiencing emotion. That’s the promise of Pathos’ revolutionary InPol technology: a design created to deliver all of that emotion.

Traditional amplifier designs force a compromise between the warmth of tubes and the control of solid-state. InPol (short for Inseguitore Pompa Lineare, or Linear Pump Tracker) erases that compromise. It’s a patented, fully balanced, class-A topology where a single triode stage handles all voltage amplification—and maintains 100% of its sonic signature—while the InPol circuit delivers the current gain needed to drive even the most demanding speakers effortlessly.

Features of InPol

1. Pure Class-A with No Distortion
InPol doesn’t dilute or "correct" the tube signal with negative feedback or transistor interference. Instead, it uses a specially designed current amplifier that mirrors the exact character of the tube stage, with zero phase shift or tonal coloration. The result? The harmonic beauty and liquidity of tubes, with the authority and grip of solid state.

2. Emotionally Engaging Sound
There’s a reason Pathos fans describe InPol amps as “addictive.” Music flows with natural presence, dimensionality, and richness—an emotional connection that standard designs just can’t replicate. Voices are human, strings are alive, and the soundstage breathes.

3. Exclusive, Patented Technology
Only Pathos builds amplifiers like this. The InPol circuit is a patented innovation, handcrafted in Italy and unavailable from any other brand. This isn’t another copycat design—it’s a true original for those who want something extraordinary.

4. The Best of Both Worlds
Tube magic meets muscle. The warmth and finesse of tubes drive the musical expression, while the InPol stage delivers the speed, control, and punch that brings complex music to life. It’s a marriage of passion and precision.

5. Class-A with Efficiency
Traditional class-A amps waste enormous energy as heat. InPol’s design cleverly maximizes thermal and electrical efficiency, delivering the full benefits of class-A operation with far fewer compromises—proving you can have purity and performance in one stunning machine.

Specifications

Type: Pure class A, double INPOL technology, fully balanced digital bias/gain set technology

Output Power: 80 W 

Tubes: 2 x ECC803S Tung-Sol, 2 X 6H30 Sovtek

Input Impedance: 20,000 Ohm

Volume Regulator: Purely resistive relays

Gain (RCA, XLR): 33 db, 39 db 

Inputs
Analog: 2 x XLR, 4 x RCA 
Digital (Only with optional HiDac Mk2 board): 1 x USB B , 1 x S/PDIF coaxial, 1 x S/PDIF optical

Outputs: 1 x RCA pre, 1 x XLR pre

Dimensions (WDH): 17" x 27" x 9" (450 x 693 x 230 mm)

Weight: 176 lb. (80 kg)