Gakuoh II

Key Features

• 300B push-pull monaural power amplifier
• Rated output of 20 watts per monoblock
• Two 300B output tubes per channel
• Newly developed pure-silver output transformer
• Self-biasing output stage
• Approximately 2 dB of overall negative feedback
• Parallel 6CG7 driver configuration
• Dual GZ34 tube rectification
• Independent power supplies for amplification and output stages
• Kondo silver-foil capacitors
• SSW silk-insulated silver internal wiring
• Copper chassis
• RCA and XLR inputs
• ACz-AVOCADO power cable included
• Hand-built in Japan

Design & Build

Gakuoh II revisits Kondo’s traditional 300B push-pull architecture with updated transformers, power supplies and signal components. A 6072 plate-follower input stage is directly coupled to a cathode follower, followed by a classic phase inverter and parallel 6CG7 driver stage.

Overall negative feedback is limited to approximately 2 dB, preserving immediacy while reducing distortion and improving loudspeaker control. The self-biasing 300B output stage simplifies maintenance and accommodates compatible current-production or vintage 300B tubes without manual bias adjustment.

Power Supply

Independent rectification circuits supply the amplification and output stages, reducing interaction between sections. Two GZ34 rectifier tubes operate in parallel to improve instantaneous current delivery, with separate transformers supplying their heaters.

Decoupling capacitors are positioned close to the associated ripple filters to create short, clean power-supply loops.

System Pairing

Gakuoh II is suited to high-sensitivity loudspeakers and systems where tonal density, vocal realism and expressive dynamics are priorities. Output taps support 4-, 8- and 16-ohm loudspeakers, with two impedances selected at the factory.

The RCA and XLR inputs are both electrically unbalanced.