Korg HA-S
The Korg Nu:Tekt HA-S offers the perfect solution for making your own custom headphone amplifier! Without requiring any soldering, the HA-S amplifier kit is easy to assemble. So you’ll be able to quickly and easily enjoy high-quality audio wherever you are. On top of that, the HA-S comes equipped with a powerful Nu:Tube fully analog triode vacuum tube. So you can be sure you’ll be getting a warm sound with a rich harmonic response that’s bound to impress every audiophile!
What’s more, you can customize the HA-S by switching the negative feedback circuit in or out of the signal path. Allowing for clean, pristine, and high-fidelity sound, or an even more harmonically rich tone. You also get two OP amps for further modifications. On top of that, there are a number of readily available circuit diagrams available for switching out discrete components of your HA-S