Q-tron Audio PA3B 2x8W Push-Pull Tube OTL Power Amplifier

The Q-tron PA3B is a high-end tube amplifier that achieves "over 10 times lower distortion" compared to other OTL (Output Transformer Less) amplifiers thanks to its unique driver circuit. The OTL design, which completely eliminates the output transformer, dramatically improves sound transparency, density, and speed. It reproduces sound that retains the warm, supple texture of tube amplifiers while also providing modern precision.
Each channel is equipped with two 6C41C tubes, and its unique driver stage ensures an 8W output. It achieves excellent characteristics, with a distortion rate of just 0.01% at 0.5W. By adopting active noise reduction technology, hum and unwanted noise are kept to extremely low levels. This is a highly quiet amplifier where even at low volumes, the nuances are beautifully expressed.

Optimized Futterman Circuit for Modern Use — Combining Clarity and Control

The PA3B uses a Futterman-style circuit optimized by Q-tron with modern components and analytical techniques.
The Futterman method, unique to OTL designs as it drives speakers directly without an output transformer, is known for its wide bandwidth and excellent linearity.
Q-tron enhances this traditional configuration with proprietary balance adjustments and stabilization techniques, achieving steadfast drive power for speaker loads and highly transparent sound.
It uses the same enclosure size as the PA12, inheriting the PA12's expansive soundstage and powerful expression, while offering the soft and dense tonal character unique to the 6C41C tubes.

Structural Beauty and Reliability through Nordic Craftsmanship

The main circuits are mounted on high-quality PCBs, and key points that directly affect sound quality are hand-wired point-to-point (PtP) by skilled technicians.
A ceramic solder support resistant up to 5kV and a 10mm thick aluminum chassis thoroughly eliminate unnecessary vibrations and minute noise.
All parts and assembly are carried out within Sweden, designed for high durability and long-term stability.

Advanced Automatic Bias Adjustment – Designed to always maintain optimal sound

The microprocessor-controlled auto-bias function automatically adjusts the optimal bias and offset during operation.
Calibration occurs just before the amplifier stops, so it starts in an ideal state the next time it is turned on.
Even when tubes are replaced, optimization is automatic, eliminating the hassle of manual adjustments.

Rich and expansive soundstage – OTL power amplifier inheriting the capabilities of the PA12

The PA3B is a model that combines the rich expression of a tube amplifier with the transparency and quick responsiveness unique to the OTL format at a high level.
A spacious soundfield, beautiful mids and highs, and tight lows naturally harmonize, portraying the essence of the music as it is.