The O2 (Objective2) Headphone Amplifier is the first design of the US blogger and electrical engineer NwAvGuy which is produced under the Common Creative License
- RCA and 3.5mm Input Connector
- 6.4mm headphone socket
- RCA output
- ALPS Stereo Potentiometer
- 220V~ 15 VAC 500mA Power supply (Euro plug)
- Gain switch (2.5x and 6.5x gain as standard)
- Size 108.5 x 84 x 30 mm (without Volume Knob)
- Black and Silver versions available
The O2 will drive all headphones you throw at it with standard gain settings, For high sensitivity in ear monitors (IEM's) and easily driven headphones it is recomended to use unity gain to be able to use more range on your volume control. For headphones that are really inefficient or hard to drive gain can be raised accordingly.
The standard settings should cover 95% of on the market available headphones. Gain settings can be amended to 1x, 2x, 3x, 4x, 5x, 6x, 7x, 8.5x, 10x and 12x. Please choose Non Standard from the Gain Options and specify your desired gain settings in the comments field underneath it.
Thanks to the RCA output (switched off when headphones are plugged in) you can use it as well to drive some monitor speakers or power amplifier. Even so it is not its original intend, it works very well...
|Frequency Response||+/- 0.1 dB|
|Noise (ref 400 mV)||-105 dB|
|THD 1 Khz 150 Ohms||0.0016%|
|Output Impedance||0.54 Ohms|
A full list of the measurements can be found in NwAvGuy's blog.