Low voltage tube headphone amp

Gareth Branwyn

Gareth Branwyn is a freelance writer and the former Editorial Director of Maker Media. He is the author or editor of over a dozen books on technology, DIY, and geek culture. He is currently a contributor to Boing Boing, Wink Books, and Wink Fun. And he has a new best-of writing collection and "lazy person's memoir," called Borg Like Me.

3922 Articles

By Gareth Branwyn

Gareth Branwyn is a freelance writer and the former Editorial Director of Maker Media. He is the author or editor of over a dozen books on technology, DIY, and geek culture. He is currently a contributor to Boing Boing, Wink Books, and Wink Fun. And he has a new best-of writing collection and "lazy person's memoir," called Borg Like Me.

3922 Articles

12AU7HeadphoneAmp_1.jpg
12AU7HeadphoneAmp_2.jpg

Gio, a MAKE subscriber from Winnipeg, Canada, sent us a link to this well-documented low voltage headphone amp project. The tube-based amp uses a single 12AU7 tube for voltage gain and a IRF510 MOSFET to supply current to drive the ‘phones. The small hybrid amplifier operates off a 12V SLA (sealed lead-acid) battery, so there are no high voltage concerns. An LM317 regulator was used as a constant current source to bias the MOSFET into class-A operation. The amp can be built for about $40-50, less if recycled parts are used.

(Psyched to see the builder using the Grado SR60 headphones, my all-around, all-time faves.)

NP-100v12: 12AU7 (ECC82) / IRF510 Headphone Amp

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