Korg Nu:Tekt HA-S

The HA-S is a kit for a battery-powered headphone amplifier featuring Nutube technology, guaranteeing outstanding sound quality anytime and anywhere. It is both elegant and compact, and even those who have not learned to use a soldering iron can assemble the HA-S independently and without assistance. Thanks to the kit design, the amplifier can even be further modified and customized to meet individual preferences. In addition to choosing between two different operational amplifiers from JRC (MUSES01 and NJM4580), the amplifier's schematics are available for free download online for those who wish to make more personalized changes. This opens up countless possibilities for sound refinement.

The Nutube used in the HA-S is a revolutionary, purely analog vacuum tube developed by KORG in collaboration with Noritake Itron Corporation. The Nutube reacts just like a conventional tube due to its structure of anode, grid, and heater wire, even though it is much more compact, reliable, and consumes significantly less energy. Therefore, the headphone amplifier can operate with just two AA batteries.

DIY headphone amplifier

No soldering required

Tube: Nutube 6P1

Sound switching via NFB switch (Negative Feedback)

Connections: INPUT/OUTPUT: Stereo mini-jack

Controls: Volume, NFB switch (negative feedback) inside the housing

Output impedance: 10 Ohms, recommended load: 15 Ohms or more

Power supply: 2 x AA alkaline batteries

Runtime: ±9 hours

Dimensions (W x D x H): 111 × 65 × 29 mm

Weight: 110 g (without batteries)

Included: User manual.