Korg HA-S Nutube Headphone Amplifier DIY Kit
Product #65498 | SKU HA-S
In stock Ships today
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Korg HA-S Nutube Headphone Amplifier DIY Kit

Product #65498 | SKU HA-S
In stock Ships today

Product Features
  • No Soldering Required.
  • Nutube 6P1 Triode Tube.
  • Battery Operated.
  • Switchable Negative Feedback Circuit.
  • Clean & Pristine or Harmonically Rich.
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Product Details
  • Product: #65498
  • SKU: HA-S
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The Korg HA-S Nutube Headphone Amplifier DIY Kit features audiophile components, injecting warm, analogue tube-driven signal boost to any sound source. With no soldering required, the HA-S is simple to assemble, so you can quickly and easily enjoy quality audio anywhere.

Developed by Korg and Noritake Itron Corp, the Nutube is a miniaturised fully analogue vacuum tube constructed with anode, grid, and filament, operating like a conventional vacuum tube in a more compact, stable, and energy efficient way. What's more, you can further customise the HA-S by switching the negative feedback (NFB) circuit in or out of the signal path, allowing for a clean, pristine, and high-fidelity sound, or a more harmonically rich tone. Also included are two OP amps for further modifications. Advanced users will appreciate the available circuit diagrams for switching out discrete components.

Key Features:

Build Your Own Headphone Amplifier
  • DIY kit allows you to build your very own headphone amplifier.
  • No soldering needed.
  • Authentic vacuum tube sound.
Built-In Nutube
  • Fully analogue vacuum tube utilising the same components as a conventional vacuum tube.
  • Constructed with an anode, grid, and filament, and operates as a complete triode tube.
  • Generates the same response and rich harmonic characteristics of conventional vacuum tubes.
  • Compact, stable, and energy efficient.
  • Transparent case allows the glow of the tube to be visible at all times.
Energy Efficient
  • Powered by a DC to DC convertor.
  • Consumes less electric current for a longer battery life.
  • Efficient design utilises a 26V line voltage using only two A4 batteries.
Customisable Sound and Modifications
  • Negative Feedback (NFB) circuit allows for a clean, pristine, and high-fidelity sound, or a warmer, more harmonically rich sound as expected from a vacuum tube.
  • NFB Switch Off: Harmonics present in the Nutube (triode tube) will be amplified to create a sound rich in harmonics, warmth, and textures.
  • NFB Switch On: Distortion ratio and frequency characteristics will be modified, creating a detailed and clean sound.
  • Sound Modification.
  • Two OP amp output options included.
  • JRC MUSE01: Premium audio oriented.
  • JRC NJM4580: Industry standard.
  • Customise and adapt the sound.
  • For advanced users.
  • Circuit diagrams available.
  • Easily change discrete components to make your own unique headphone amp matching your desired tone and performance.


Vacuum Tube Nutube 6P1
Connections Input/Output: 2 x 1/8" / 3.5 mm Stereo Mini-Jack
Controls Volume, Internal Negative Feedback (NFB) Switch
Impedance Output Impedance: 10 Ohms
Recommended Load: 15 Ohms or More
Power 2 x AAA Alkaline Batteries
Battery Life 9 Hours Approximately
Dimensions (W x D x H) 4.4 x 2.6 x 1.1" / 111.0 x 65.0 x 29.0 mm
Weight Without Batteries: 3.9 oz / 110.0 g

Delivery Times

Australian Shipping Via DHL
DHL now offer a great express shipping service to Australia from New Zealand. We are proud to be able to offer overnight shipping to main cities on the east coast of Australia. These main centers include:

  • Brisbane
  • Sydney
  • Adelaide

Whilst this service is extremely efficient and will be delivered overnight 99.9% of the time, it cannot be guaranteed. In the case where something were to go wrong with your delivery and it did not arrive overnight, it will most likely be delivered by the next day.

While not all major cities are eligible for overnight delivery, they still benefit from this great service. Other centers throughout Australia will have a typical delivery ETA of 2-4 days. (Excluding rural delivery address where this ETA can be extended to an additional three or more days).

If you require urgent shipping and you don’t reside in one of the cities stated above, please contact us and we can find a solution that works best for you.

Please Note: Shipping via DHL is not available to PO boxes and/ or parcelboxes etc.

In The Box

  • Korg HA-S Nutube Headphone Amplifier DIY Kit.


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  • Product: Korg HA-S Nutube Headphone Amplifier DIY Kit
  • Manufacturer: Korg
  • Model: HA-S
  • SKU: HA-S
  • RM Product #: 65498