HyperDrive-2 Headphone Amp / Preamp

[xrk971]

I use it as a preamp mostly. For that it excels and is convenient. 3 inputs. 2 outputs. 3 gains plus volume. Mute.

 

[xrk971]

The HyperDrive-2 has been my daily use preamp for many months now. It is rock solid. The Russian 6N1P’s are military grade and very rugged. Interesting in that they measure and sound better than European made E88CC. I leave it on 24/7 almost.

 

[xrk971]

Hi Folks,
A new review of the HD-2 just came out.

https://hometheaterhifi.com/reviews/headphone-amplifier/lsa-hyperdrive-2-headphone-amplifier-review/

 

[xrk971]

A new ventilated top panel is now standard on the second production batch. Looks cool and lets the amp run cool.

 

[xrk971]

Testing of the HD-2 as a headphone amp yielded some great numbers. The harmonic profile is SE Class A like with dominant second harmonic and decreasing amplitude of higher orders. THD is about 0.004% under 60mW and still very low 0.0072% at 620mW into 33ohm load. Max power was at 1.7W and THD there is 0.011% and still exhibiting same SE Class A profile. Background noise level with no music playing is very quiet at -122dB with 0dB referenced to 1.0Vrms.

Test setup used Focusrite 4i4 3rd gen with balanced input voltage divider, Victor’s 1kHz oscillator, and REW on PC with 4 series parallel 2W 33ohm metal thin film resistors as dummy load:

33ohm 8W dummy load:

This is FFT for 293mW into 33ohms (0.0055% THD):

This is background noise FFT with inputs shorted at 12dB gain setting: