The BOM and PDF files in the Resources section were revised.MOUSER INVENTORY: As of November 30th everything on the current BOM, except the volume control, is in stock and all prices are correct.
The reality is you The O2 is Open Source Hardware under a Creative Commons license.
In addition to the language in the CC-BY-ND License, the O2 design is offered “as-is” with no warranty of any kind, either expressed or implied, including its suitability for anything you might want to use it for. In plain English: If you can’t make the O2 work correctly, or as you had hoped, or damage your headphones, or your house burns down and your wife leaves you, you can’t blame me. For more, please see: Open Source Hardware This work is licensed under a Creative Commons Attribution-No Derivs 3.0 Unported License.
If someone wants to roll the dice and make a few hundred O2 amps things get even better.
They can buy in volume, run the circuit boards on a wave solder line, and probably sell the O2 at a nice profit for $99 or less.
For the history see the first article covering the premise, and the second article discussing the design process.
THE PRICE DETAILS: All the parts to build the O2’s fully functional circuit board should be around .
” Here are some possibilities: PLEASE DON’T MESS UP A GOOD THING: Many of the smaller commercial audiophile manufactures apparently lack the ability to properly measure the performance of their products.
And DIY designers are typically even less well equipped.
The first alternate volume pot is in stock and differs only in taper. CHANNEL MIS-MATCH & GAIN SWITCH CLEARANCE: The corner of the gain switch closest to R21 may touch a via (small exposed pad on the PC board) and cause a gain change in one channel making the channels sound unbalanced. METAL SHAVINGS FROM CASE SCREWS – A few users have reported the screws to attach the panels to the Box Enclosures case produce aluminum shavings that can end up creating unwanted connections on the PC board (short circuits) which may damage the amp, possibly even headphones and/or at least cause odd behavior.
So, as a precaution, install all 8 self-tapping screws first into an empty case, remove them, and blow out any shavings that might be created.
These changes are related to some users reporting their O2 would rapidly turn on and off when the batteries were low.