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Q-tron Audio PA3B 2x8W push-pull tube OTL power amplifier

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Q-tron Audio PA3B 2x8W push-pull tube OTL power amplifier

Normal price ¥1,450,000 円
Normal price Sale Price ¥1,450,000 円
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This product will be made to order. Delivery time will be around 55 days.

Sound with superb transparency

Vacuum tube amplifier without output transformer

Description

The A3B is a vacuum tube OTL amplifier that achieves 10 times lower distortion than other OTL (Output Transformer Less) amplifiers through a unique driver circuit. With two 6C41C tubes on each channel, the unique driver stage achieves an output power of 8 W. Distortion at 0.5 W is as low as 0.01%, and active noise reduction keeps hum and noise to a very low level.

The PA3B employs the Futterman circuit, a circuit design that eliminates the need for an output transformer, resulting in excellent frequency response and outstanding low distortion. The Futterman circuit is known for its ability to maximize sound transparency and realism, especially in OTL (output transformerless) amplifiers.

The PA3B is a lower output version of the PA12, which was reviewed by Dick Olsher in "Enjoy The Music" and described as "The Q-tron PA-12 is unmatched. He also praised it as "a tube amplifier that redefines the possibilities of push-pull design. The PA12's excellent sound quality and transparency can be fully enjoyed with the PA3B.


The PA3B design uses large PCB boards, except for critical parts that have a significant impact on sound quality, and critical parts are assembled using point-to-point (PtP) technology. The structure is constructed to withstand up to 5 kV using ceramic solder supports. The chassis is made of 10 mm thick aluminum, providing exceptional mechanical stability and completely eliminating noise caused by vibration.

The PA3B takes the rich expressiveness of a tube amplifier and the transparency of an OTL amplifier to the extreme. Its clear sound delivers new excitement to true music lovers.


The unique Auto Bias adjustment automatically adjusts the optimum bias and offset. This avoids crossover distortion caused by conventional "auto-bias" circuitry, providing clean, accurate sound. Just before the amplifier is turned off, a microprocessor is activated and automatically adjusts the bias and offset to optimal values. Also, when a power tube is replaced, the microprocessor automatically makes the optimal bias adjustment for the new tube. This feature ensures that the best performance and sound quality is always maintained, making it a very easy and reliable maintenance option for tube amplifier owners.
Spec.
Tubes 6C41C x4, 6H2n-EB x5, 6H6PI x2
Outputs 8W (into 8Ω, distortion <1%), 5W (into 4Ω, distortion <1%)
Distortion < 0.01% at 0.5W
Frequency Response 5Hz - 150kHz
Power Bandwidth 10Hz~100KHz
Rise Time 0.5μs (microsecond)
Hum and Noise < -100dBA
Output impedance

Input terminal RCA phono + XLR
Dimensions 430 x 240 x 400 mm, (W x H x D)
Weight 21 kg