The H26 amplifier stage is built around a fully balanced signal path and a discrete Class A circuit. Separate positive and negative signal paths provide precise signal handling, stable load capability, and substantial power reserves.

The amplifier uses eight pairs of power transistors, providing significant current delivery for low-impedance headphones with higher power requirements. In Class A operation, the output stage runs with continuous quiescent current, helping to avoid crossover distortion caused by switching between different transistor branches.

The input stage uses a fully balanced architecture, allowing signals received through the XLR connection to remain within a balanced system throughout the signal path. This design reduces the effect of common-mode interference and helps maintain electrical separation between the two channels.

The unbalanced signal received through the RCA input is routed through a dedicated conversion stage before entering the balanced amplifier circuit. This allows DACs, CD players, and network players with conventional RCA outputs to make use of the H26's complete internal amplification structure.

High-power Class A amplification requires a stable and appropriately sized power supply. The H26 uses two 50-watt toroidal transformers, which separately power the left and right channels.

Separate power delivery for each channel reduces interaction between the amplifier sections, particularly under greater dynamic load. The high-speed, low-noise rectifier stage is paired with four Nichicon reservoir capacitors, increasing the power supply's energy reserve and stability under load.

The H26 does not use a conventional rotary potentiometer for volume adjustment. The large front-panel control operates a relay matrix that sets the analogue signal level in precisely defined steps.

The system controls all four branches of the fully balanced signal path in coordination, helping to reduce left-to-right channel imbalance even at low volume levels. The preamplifier stage uses two LM49720 dual operational amplifiers, which handle low-noise, low-distortion line-level signals.

The Gustard H26 can accommodate three stereo analogue sources. The rear panel features one RCA and two XLR inputs, allowing multiple DACs, streamers, CD players, or other line-level components to be connected simultaneously.

The preamplified signal can be sent through both balanced XLR and unbalanced RCA outputs. Both interfaces operate with a 100-ohm output impedance, allowing suitable matching with most active speakers and power amplifiers. The 20 Hz to 80 kHz frequency response also provides wide-band analogue signal handling.

The front panel provides connections for both conventional and balanced headphone cables. Alongside the 6.35 mm output, there is a 4.4 mm Pentaconn socket and a 4-pin XLR connector.

The 6.35 mm output has an impedance of 0.05 ohm, while the balanced outputs have an impedance of 0.1 ohm. The low output impedance reduces the effect of headphone impedance variations on frequency response and provides favourable electrical damping for the connected driver.

The H26 preamplifier function allows the same analogue sources to be used through both headphones and speakers. By switching off the preamp output, the power amplifier or active speakers can be muted while the headphone amplifier continues to operate.

The headphone amplifier stage can also be switched off separately, allowing the device to be used exclusively as a preamplifier. This operating mode reduces the number of unnecessarily active circuit sections and simplifies integration of the H26 into systems where headphone and speaker listening are regularly alternated.

Operation of the Gustard H26 centres on the large volume control and clear front-panel display. Inputs, gain level, and the headphone and preamplifier outputs can be controlled directly, while the included remote control provides easy access to the main functions.

The low-profile chassis fits neatly into desktop and conventional hi-fi systems with its clean appearance, while the side cooling surfaces dissipate the heat generated during Class A amplifier operation.