Hybrid Tube Amplifier: A DIY Kit Review

This review explores a DIY hybrid power amplifier kit that utilizes a 6J1 tube and an LM1875T IC. The kit offers an opportunity to build a unique amplifier that combines the warmth of the 6J1 vacuum tube with the power and efficiency of the IC LM1875T.

How it looks after assembly:

DIY_hybrid_tube_amplifier

Key Features:

  • Hybrid design: Combines tubes and ICs for enhanced sound quality.
  • Output power: 20W (maximum 30W)
  • Speaker impedance: 4-8Ω
  • Total harmonic distortion (THD): <0.04%
  • Power supply: Dual AC 18V/3A (maximum 19V, minimum 18V)
  • Headphone output: Yes, with 0.8 gain
  • Dimensions: 120 x 60 x 35mm

Kit Contents:

  • Printed circuit board (PCB)
  • All necessary electronic components
  • Assembly instructions (in Chinese)

Advantages:

  • Decent sound quality: The hybrid design delivers warm, dynamic, and detailed sound.
  • Easy assembly: The assembly process is straightforward even for beginners.
  • Affordable: The kit is priced reasonably.

Disadvantages:

  • Dual power supply requirement: The circuit necessitates a dual power supply.
  • Schematic errors: The schematic indicates an 18-0-18 power supply, but the kit's electrolytic capacitors are rated only for 25V, hence a 15-0-15 power supply is used.
  • Underpowered tubes: The tubes appear to be primarily for aesthetic purposes, as their yellow glow is achieved using LEDs beneath them.
  • Overheating resistor in the filament circuit: The resistor becomes noticeably hot.
  • No enclosure: An enclosure is not included.

Overall, this kit presents a decent option for electronics enthusiasts seeking to build a hybrid power amplifier. It's easy to assemble, affordable, and delivers satisfying sound quality.

Circuit Diagram:

hybrid_tube_amplifier_circuit

Assembly Video:

A video demonstrating the assembly process:

Additional Information:

The kit can be purchased from the manufacturer's website - ICStation.

Date: 08.09.2024