Audio Hungary QUALITON A75i Integrated Amplifier

KT-Series Power TubesThe amplifier’s power block is specifically designed for KT-series power tubes, known for their high power, low distortion and magical sound character. This creates the perfect foundation for our amplifier, further enhanced by our custom output transformers for excellent low and high frequency performance. Moreover, our proprietary Automatic Bias System ensures seamless operation with KT90, KT120, KT150, and KT170 power tubes, so you’re free to choose your favorite without needing any modifications.

Custom Output TransformersThe transformers of our amplifiers are custom-designed and built in our in-house transformer workshop. Our output transformers are constructed using high-permeability, large cross-section toroidal magnetic cores, which undergo initial impregnation during the production process. Following this, the winding process begins, utilizing a multi-layered, sectioned, and specially arranged winding configuration. This meticulous design ensures optimal performance across both low and high frequencies. Once the winding is complete, the transformers are encased in metal shielding cans to minimize electromagnetic interference. Finally, they are potted using an epoxy compound to eliminate mechanical vibrations and associated noises.

Custom Power TransformerJust like our output transformers, our power transformers are also custom-designed and built in our in-house transformer workshop. We manufacture them with the same precision and attention to details: the high-permeability, large cross-section toroidal cores are also impregnated, and then the winding process follows. The parameters of the windings are designed to avoid saturation of the magnetic core and to ensure efficient operation even under heavy load conditions. It is important to note that we use double electromagnetic shielding for our power transformers. Finally, we employ the same epoxy compound used to pot the output transformers to eliminate mechanical vibrations and associated noises.

Automatic Bias SystemThis circuit continuously monitors the behavior of each tube and regulates the bias voltages accordingly, ensuring the smallest possible output voltage noise while guaranteeing the highest degree of linearity of the output stage. Additionally, it prevents the sensitive, high-permeability output transformer cores from saturating by precisely equalizing the quiescent currents of the power tubes. Furthermore, the bias system incorporates a built-in soft-start function, which prevents the tubes from drawing excessive current during start-up and eliminates pops and noises. The result is that no further adjustment is required once the electron tubes supplied with the unit have been installed; the Automatic Bias System takes care of everything.

Relay-Controlled Input SelectionThe amplifier features a total of four analog inputs: three unbalanced Line IN and one balanced Line IN. Selection between these inputs is accomplished using precision, low-power, ultra-miniature Japanese relays with ultra-low contact resistance gold overlay silver contacts. The front panel Status LEDs indicate the currently active or inactive inputs.

ALPS Motorized Volume ControlThe japanese made ALPS passive volume control potentiometers are a top choice among audiophiles due to their high quality, low noise, and smooth operation. Precision engineering and premium materials ensure superior sound performance, while minimal electrical noise keeps the audio signal clean and accurate. Their design allows for consistent volume adjustments, crucial for maintaining fidelity. Known for durability, these potentiometers offer reliable performance over time.

4-Function Remote ControlThe remote control features a black matte finish. Alongside the basic VOLUME UP and VOLUME DOWN functions, it also includes a convenient MUTE function and an INPUT SELECTION button.

Special ComponentsTested and Selected Vacuum Tubes

The power tubes in all our amplifiers come in matched quads. The preamp tubes are selected for low noise, symmetry and minimum distortion.

Gold-Plated Ceramic Tube Sockets
Ensuring reliable connections.

Gold-Plated Audio Terminals
Enhancing signal transmission quality.

Film Capacitors
We exclusively use film capacitors in our audio circuits for optimal performance.

Ceramic Composition Resistors
These resistors are placed in critical positions to enhance reliability.

Long-Life, High-Temperature-Tolerant Capacitors
Employed in our power supplies to withstand demanding conditions.