Tube Headphone Amplifier

Project Specs:

    • Months of work: Dec 2008
    • Approximate Build Time: 2 Weeks
    • Max Voltage: 250V
    • Max Stored Energy: ~50J

This project was my first amplifier build. I had just previously gotten a pair of Sennheiser HD600 headphones that are 300ohm impedence, and really needed an amp to drive them well. Due to the simplicity I decided to go with a tube amplifier and followed a common tube amplifier schematic design.

The first power supply produced some 120hz humm in the output however this was solved by adding two additional stages of RC ripple filtering to the B+ high voltage power supply.

This amplifier was used for almost a year, until I discovered it sounded awful and then went solid state. I do not suggest this schematic, it’s a pretty crappy headphone amp.

Schematic (I don’t take credit for this circuit, don’t recall where it’s from)


Point to Point Wiring


Completed Amp

  1. Nice work, and in stereo too. I see you like High Voltage stuff, which brought to mind “starved-circuit”. Where very high plate load resistor drops plate voltage to unusually low voltages, and produces high amplification. Plate supply voltage can be several thousand volts, limited by arcing. Amplification can get so high that electron flow can create noise. “Popular Electronics” published an article almost 50 years ago called “Starved Circuit Amplifier”, and “Google” provided this link
    High Voltage (>20kv) and vacuum tubes can produce “Hard x-ray” from the “getter” coating inside the tube. I thought you may enjoy this article it was published in “Scientific American” long ago. Light bulbs can also be used for this. I thought the thickness gauge photo looked nice. Uncommon knowledge, honey, mayonnaise and diamonds refract x-rays, a power supply filter set to resonate to multiples of the line frequency will produce high voltage in proportion to the “Q” of the circuit, not the turn ratio of the transformer. Sorry for being so long winded, I’m getting old. “Enjoy Life! It’s limited. You only get as much as you take” Carl

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