DIY headphone amp packs a punch

W.HeadAmp.302Ah, nothing like the sweet sound of good headphones, up close and personal with the best of both worlds – a 12AU7 tube front end with dual IRF510 power MOSFETs as the drivers. Elegant sound that packs a punch, and it runs on 12 volts to boot.

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W.DSCN0401Based on the NP-100v12, a portable combo tube/semiconductor headphone amp designed by Rogers Gomez, the mini-circuit board and low voltage design means it can travel in a backpack. I built mine in a little wooden tea box, refinished in a red mahogany laquer with the innards assembled within.

Photos of the various versions of my board can be seen here. My first attempt meant the whole board W.HeadAmp.300and the wiring were crammed into the little wooden box.

It was a great idea and looked real cool, but it was anything but cool. Gomez states that the amplifier can run without heatsinks, but in a closed small container, it heated up real fast. Lots of thermal noise and components overheating.

Also, there was no practical way to properly mount the board other than glue, so things got a bit wobbly.  Lots of shorts and pops and buzzes and hums and cutting in and out.W.HeadAmp1

So enough of that. I don’t really need a backpack headamp. What I need is a desktop unit.  So my final version III was built in an old modem case, with the lid off.

I also built the power supply inside. This way, I could do proper heatsinking and lay the circuit out with a bit of room.  It runs W.DSCN0106flawlessly now and the semiconductors barely get warm to the touch.

You can view the original project page over at DIY Audio Projects here:

Special thanks to Rogers Gomez  for the excellent design and helpful construction tips.W.DSCN0123

If you’re interested in this or any of our other products or services, please contact Duncan McAllister at Nebulix Digital Media for a consultation or quotation at




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