AMP14 Vacuum Nutube 4.4mm Balanced AMP Card

6th Gen KORG Nutube
An Engaging, Unique Vacuum Tube Sound

Provided by KORG and Noritake, the 6th Gen Nutube operates exactly as a conventional triode vacuum tube and creates the same characteristic rich overtones that are sought after in triode tubes. At the same time, the Nutube achieves substantial power saving, miniaturization, and quality improvements when compared with a conventional vacuum tube.

The AMP14 completes voltage amplification through the Nutube, while giving AMP14 An Engaging, Unique Vacuum Tube Sound while delivering excellent linearity.

4.4mm Balanced PO + 4.4mm Balanced LO

The AMP14 utilizes Nutube 6P1 as a voltage amplifier, followed by a JFET differential converter to realize the L-, L+, R+, R- differential output. AMP14 adopts two JRC volume control chips, which forms a total 4 channel true balanced volume control. The signal then passes through the 4 channel balanced output buffer stage. Pentaconn 4.4mm balanced sockets are used, which have excellent acoustic quality and durability.

5.2Vrms Balanced PO Output

1.8vrms Balanced LO Output

Cathode Input,
Lower Impedance, Less Interference

The AMP14 adopts a cathode input. The cathode impedance is lower than the grid, resulting in reduced signal interference from external sources. AMP14 is designed to have excellent noise floor control. Also, the WiFi interference is low, which brings a better online streaming experience. The tube microphonic effect is also well controlled.

Dedicated Battery +
Dual Linear Technology DC-DC Chips
Reaching The Performance Upper Limit

The AMP section of the DX320/DX300 has its own battery power, which is perfect for the AMP14, as it is an AMP card with strict power supply requirements. The AMP14 utilizes two pieces of high performance DC-DC chips from Linear Technology, with a total of 4 DC-DC power supplies. One DC-DC is 3.6V for the cathode through a low-noise LDO, and one is 14V for the anode of Nutube, one is +8V and one is -8V, which constitutes the 16V voltage swing that feeds the OPAMPS.

Advanced Circuit Design

1. Inherited from AMP9, adopting Toshiba 2SK209 field effect transistor as the Nutube signal output buffer.
2. Signal grounding and shield grounding separated to prevent noise interference.
3. Appropriate negative feedback to the amplifier circuit effectively reduces distortion and extends the frequency bandwidth.
4. By adding a dedicated JRC ultra-low noise volume control, the noise floor is reduced when using low volume or during quieter parts of the music. Transparency is also enhanced.

Hand Matched
So That Every One Is A Masterpiece

Each AMP14 is tested and matched with an AP audio analyzer, with 3 multi-turn potentiometers on the AMP14 board, which are manually calibrated and matched by engineers to present the optimal performance of the Nutube.

The AMP14 brings a clean extended upper frequency and a sweet and engaging sound together for your musical enjoyment.

AMP14 is compatible with the DX320/DX300

Please update the firmware to the latest version to have an optimized support.

When streaming, the AMP14 may experience subtle WiFi interference when data buffering. This is almost inaudible at normal volumes. The sensitivity and impedance of different earphones may result the difference of the subtle WiFi interference.