Pathos Logos MkII – Tube Naturalness and MOSFET Power in Italian Form
The Pathos Logos MkII is designed for listeners who want the natural, richly textured and musically engaging character of tube amplification combined with substantial power, confident loudspeaker control and genuine high-end construction. This Italian integrated amplifier combines an ECC88 tube preamplifier with a high-current dual-mono MOSFET output stage.
The Logos MkII immediately stands apart from conventional amplifier design. Its curved aluminium front panel, real-wood insert, mirrored tube chamber, substantial side-mounted heatsinks and centrally positioned volume control are more than decorative features. The form closely follows the engineering: the exposed tubes are active components of the preamplifier, while the large cooling surfaces dissipate heat generated by the heavily biased output stage.
Class A Tube Preamplifier and Class AB MOSFET Output Stage
The hybrid architecture of the Logos MkII is intended to combine the strengths of two different amplification technologies within one coherent design. Its preamplifier stage uses two 6922/ECC88 vacuum tubes operating in pure Class A. This section processes the low-level music signal and plays a significant role in defining tonal character, spatial presentation and midrange naturalness.
The loudspeakers are driven by a powerful, heavily biased MOSFET output stage operating in Class AB. This provides the current delivery, dynamic headroom and bass control required by larger floorstanding loudspeakers and models with more demanding impedance characteristics.
The two technologies are not intended to produce separate or competing sonic characters. The aim of the design is for the fluid and natural presentation of the tube preamplifier to work together with the authority and control of the MOSFET power stage.
Zero-Feedback Dual-Mono Construction
Pathos designed the Logos MkII without global negative feedback. This is a technically demanding approach that requires carefully selected components, stable operating points and a well-engineered power supply.
The power amplifier section uses a dual-mono layout, giving the left and right channels a high degree of separation in both power delivery and signal routing. Reduced interaction between the two channels supports more stable stereo imaging, clearer spatial information and more consistent dynamic behaviour.
Signals from balanced source components remain balanced up to the tube stage. The two XLR inputs are therefore more than a convenient connection option: they allow compatible sources to make meaningful use of the amplifier's internal architecture.
The Technical Improvements of the MkII
The MkII is considerably more than a cosmetic update. Pathos increased the anode voltage of the tubes to provide a more favourable and linear operating point. The tube preamplifier received a dedicated regulated power supply, while electrolytic capacitors were positioned more strategically throughout the signal path and close to the individual MOSFET devices.
The technical objective was faster energy delivery, more accurate transient response and greater stability as the load changes. In practical listening terms, this approach is intended to produce more convincing dynamics, improved rhythmic precision and more clearly separated musical detail.
The amplifier also incorporates Hall-effect protection against short circuits and overloads. This helps protect both the amplifier and the connected loudspeakers without placing a conventional protective circuit unnecessarily in the music signal path.
Power for Serious Loudspeakers
The Pathos Logos MkII delivers 110 watts RMS per channel into 8 ohms and up to 220 watts per channel into 4 ohms. This provides more than comfortable power reserves, allowing the amplifier to serve as the centre of a serious system built around larger floorstanding or lower-sensitivity loudspeakers.
A damping factor of 360 supports more precise electrical control of the drive units, particularly in the bass range. Its wide 5 Hz to 140 kHz frequency response also indicates that the circuit was designed for fast and phase-consistent signal transmission well beyond the audible frequency range.
The available power is not simply an end in itself. One of the main objectives of the Logos MkII is to combine substantial energy reserves with the refinement of its tube preamplifier. Fine detail and spatial information can therefore remain important at lower listening levels, while the MOSFET output stage provides the necessary stability and dynamic capability when the volume is increased.
Precise Digitally Controlled Analogue Volume Regulation
Volume is controlled by a Burr-Brown PGA2310 circuit with 100 individual steps. Although the control interface is digital, the music signal itself passes through an analogue, resistive volume-regulation circuit.
This arrangement supports accurate channel tracking, repeatable settings and smooth adjustment throughout the volume range. Separate volume levels can also be stored for individual inputs, making it easier to switch between source components with different output voltages.
Display brightness is adjustable, while volume, input selection, mute and standby functions can all be operated from the distinctive remote control made from real wood.
An Analogue System Hub for High-Quality Sources
The Logos MkII provides two balanced XLR inputs and five conventional stereo RCA line inputs. This gives it enough flexibility for a CD player, DAC, network streamer, phono preamplifier, tape machine or other analogue sources.
The rear panel also provides a variable preamplifier output and a separate line-level output. The Pre Out connection can be used with an external power amplifier, active subwoofer or another line-level component.
Pathos also offered the optional HiDac Mk2 digital module for the Logos MkII. This module adds a USB-B input and two coaxial S/PDIF connections. It was not standard equipment, however. The rear panel of this particular example indicates the purely analogue configuration, so a separate DAC or network player is required for connecting digital sources.
Italian Design with Genuine Engineering Substance
The Logos MkII makes no attempt to disappear into the background. Solid aluminium, warm-toned wood, polished metal surfaces and visible vacuum tubes create an appearance that is simultaneously modern, technical and handcrafted.
Behind its distinctive exterior is a substantial amplifier. The chassis measures 430 millimetres wide, 420 millimetres deep and 170 millimetres high, with a weight of approximately 28 kilograms. It therefore requires a stable equipment support with adequate load capacity and sufficient free space around the large heatsinks.
The upper ventilation openings and side-mounted cooling surfaces must not be obstructed. The Class A tube preamplifier and heavily biased output stage generate considerable heat during operation, making correct ventilation important for long-term reliability.
Key Features
Hybrid integrated stereo amplifier
Two 6922/ECC88 vacuum tubes in the preamplifier stage
Pure Class A tube preamplifier
High-current MOSFET Class AB power amplifier
Zero global negative-feedback design
Dual-mono power-amplifier architecture
Balanced signal path up to the tube stage
2 × 110 watts RMS into 8 ohms
Up to 2 × 220 watts into 4 ohms
Frequency response of 5 Hz–140 kHz
Damping factor of 360 into 8 ohms
Burr-Brown PGA2310 volume regulator
100-step, digitally controlled analogue volume adjustment
Individually stored volume settings for each input
Two balanced XLR line inputs
Five stereo RCA line inputs
Preamplifier output for an external power amplifier or active subwoofer
Separate line-level output
Adjustable display brightness
Full remote-control operation
Hall-effect short-circuit and overload protection
Real-wood and aluminium construction
Large side-mounted heatsinks
Chassis dimensions: 430 × 170 × 420 mm
Weight: approximately 28 kilograms
Who Is It For?
The Pathos Logos MkII is particularly well suited to listeners who appreciate the natural tonality and spatial presentation associated with tube amplification but do not want to sacrifice the power, bass control and loudspeaker-driving ability of a transistor output stage.
Its substantial reserves make it a capable partner for larger floorstanding loudspeakers and more demanding designs. With two XLR and five RCA inputs, it can also serve as the long-term centre of a system containing several high-quality analogue sources.
It will also appeal to anyone who considers design and material quality an important part of owning a high-end component. The Logos MkII is not a conventional black box but a defining visual element of the listening room—an Italian amplifier in which appearance, circuit design and musical purpose form part of the same idea.
The central strength of the Pathos Logos MkII is balance. It combines the refinement of a tube preamplifier with the authority of a powerful MOSFET output stage, distinctive industrial design with serious engineering, and high-end construction with practical everyday operation.
