AMP13 3CH Vacuum Nutube AMP Card 3.5mm+3.5mm

KORG Nutube 6th Gen

AMP13 is compatible with the DX320/DX300. Please update the firmware to the latest one to have an optimized support of the AMP13.

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 AMP13 completes voltage amplification through the vacuum Nutube, while giving AMP13 An Engaging, Unique Vacuum Tube Sound, delivering excellent linearity.

3.5mm+3.5mm Low Noise Tube Output + Maximized Output Unique Dual Single Ended Outputs

The voltage amplification capability of the Nutube 6P1 is limited. Two stages of amplification are necessary to obtain higher output power. To have both a stronger tube signature and a higher output power, the AMP13 adopts a dual 3.5mm single-ended output design with low noise tube output and 'maximized output at the same time.

Low Noise Tube Output:
The AMP13 utilizes Nutube 6P1 as a voltage amplifier. This is followed by a digital volume control and current amplification. The low noise tube output is the output after the first stage of amplification. Although the output is not high using this design, the Nutube has a stronger tube sound signature and noise control is excellent. (2.5Vrms)

Maximized Output:
The output passes through a first stage Nutube amplifier, followed by a secondary amplification. With this, the AMP13 has a higher voltage and current output capability, that is, a better driving capability for headphones and IEMs. (4.1Vrms)

Three Channel Amplifier Unlocking A Better Performance

The single-ended output of ordinary players generally only has left and right dual channel amplification.

Although the Nutube 6P1 has the same characteristic rich overtones as conventional triode vacuum tubes, its low output capability and poorer noise control have always been a design problem. On the AMP13, we use three-channel amplification. Utlizing the OPA1622 to amplify the output ground signal, the noise floor is dropped substantially, while enhancing dynamics and Improving the Nutube performance.

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 AMP13, as it is an AMP card with strict power supply requirements. The AMP13 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 1.8V for the cathode through a low-noise LDO, and one is 21V 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 25K209 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 AMP13 is tested and matched with an AP audio analyzer, with 3 multi-turn potentiometers on the AMP13 board, which are manually calibrated and matched, by engineers to present the optimal performance of the Nutube. The AMP13 brings a clean extended upper frequency and a sweet and engaging sound together for your musical enjoyment.