Side Project: Nwavguy's O2 Headphone Amplifier

16.10.17 09:52 AM By skrodahl

I've been getting my new hobby room ready, and I knew I needed some kind of stereo system in there. Preferably one that didn't annoy others in the house, so I ended up ordering PCBs from Nwavguy's gerber files. Yup, I'm gonna use headphones. :)

White o2 headphone amp PCBs

The components that I didn't have at home were ordered from DigiKey, and I ended up doing quite a few component substitutions. The cabinet + front and back panels were ordered from Headnhifi.

O2 headphone amp components from DigiKey
Empty O2 cabinet and panels from Headnhifi

I did spend a lot of time identifying the right components. There are a lot of different resistor values, and they have to be cross referenced with the BoM. Of course, it didn't help that I have a box with all E24 resistor values that aren't sorted in any way.


Once the sorting of components was done, it didn't actually take long to solder the thing. I'm really happy I got the recommended enclosure and panels. This thing looks really great.

O2 headphone amp, soldering done
Completed O2 headphone amplifier

Initial impressions are really good. My main problem (until the Sennheiser HD 600 headphones arrive) is that I only have an old pair of Koss PortaPro available. The foam around the earpieces is really old, and creates a cloud of tiny black dust...

Koss PortaPro headphones