Project Polaris is somewhat similar to project Ember in that it uses the same power output stage.
Instead of a tube this design has a J-FET which has similar transfer characteristics as tubes and a similar amount and spectrum of 'added harmonics' while being an all Solid State design.
You can configure the bandwidth for special occasions, say when using NOS DAC's or other sources that have high amounts of ultrasonics that do not have any relation to the sound.
On the 'wide' setting the frequency range (-3dB) runs from 0.5Hz to 350kHz in the 'small' setting from 0.5Hz to 20kHz.
Gain can also be changed by a jumper in 3 steps + via a 'gain module' that can provide extra attenuation when the source has an unusual high output voltage.
Of course the output resistance can be set in 3 steps (0.1 Ohm, 35 Ohm and 120 Ohm) Startup protection circuit
Advanced cooling design to keep temps nice and low when demand is high
It has Pre-amp output so it can double as a volume controlled pre-amplifier. The RCA out is switched off when a headphone is inserted but this option can be disabled so the RCA out is present even when a headphone is connected.
Very efficient, low power consumption, low temperatures.
Loads of headroom and more than enough output power (up to 2.4W, depending on headphone and settings)
Comes with wide input voltage range 48V SMPS power supply.
Not an audiophile feature, but you can change the power LED's brightness or turn it off.
You can also rather easily change out the LED without soldering to change the desired colour
Specifications:
Solid state output stage
Power consumption: (0.03A cont, 0.25A peak)
Power supply: 48VDC
Input Resistance: 11k or 21k depending on gain setting
Gain: 12.5X / 7.5X / 4.5X without Attenuation Module. With Module, reduce by ½ (or even more if needed on request).
Max Output voltage: 15.7Vrms at 300Ohm
Output Resistance: Selectable 0.1, 35 or 120 Ohm
Dynamic Range: 108dB
Noise level: -109dB
Crosstalk: -98dB
THD: > 0.045% becomes lower at lower signal levels consists of mostly 2nd harmonics and much less 3rd harmonics.
Suitable for: 16-600ohm Headphones
Frequency range wide bandwidth setting: 0.5Hz - 350kHz (-3dB) = 1Hz - 170kHz (-0.5dB)
Frequency range medium bandwidth setting: 0.5Hz - 35kHz (-3dB) = 1Hz - 15kHz (-0.5dB)
Frequency range small bandwidth setting: 0.5Hz - 20kHz (-3dB) = 1Hz - 9kHz (-0.5dB)
schematics: http://www.mediafire.com/view/ma5robcs1zvjjwf/Polaris_schematic.pdf
..
