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Objective 2: The open source headphone amp

o2 Objective 2: The open source headphone amp

NwAvGuy is a man who recently made quite a few enemies in some audio communities and got banned from some enthusiast/audiophile forums as well. He’s rather outspoken and doesn’t beat around the bush when it comes to pointing out flaws in shoddily designed – and often overpriced – gear (which sometimes goes against commercial interests of said sites, unsurprisingly).

Since some of his adversaries asked if he can only criticize other people’s designs or if he indeed has the skills to create better performing devices, he now has a point to prove, it seems. The result is known as the O2 – short for “Objective 2″ – headphone amp.

NwAvGuy was very transparent on his blog regarding the design process of the O2, and he open sourced the schematics under a Creative Commons license. He will not be selling finished amps, but everyone is free to build their own – no matter if for personal use, or for commercial purposes.

Some design principles of the O2 are:

  • State of the art audio performance with most any headphone out there, from the most sensitive multi-armature IEMs to full-sized high-impedance headphones
  • Usage of inexpensive quality parts instead of overpriced “boutique” components
  • Easy to solder and assemble (no SMT components)
  • Precise volume control (no crackling or audible imbalance at low volume levels)
  • No dangerous clicks/pops at turning on/off
  • Usable as a portable or a desktop amp (batteries and AC power)
  • Switchable gain
  • Battery rundown protection

In the end, the price of the parts used in the O2 should come to about $30 (without enclosure, panels, or wallwart) – and according to NwAvGuy the audio performance should be indistinguishable from top quality studio gear like the $1600 Benchmark DAC1. I, for one, am very interested in building my own O2 to find out how it performs.

Detailed info on NwAvGuy’s blog: Part 1, Part 2, Part 3 – and we also got an ABI forum thread about the O2 going on.