The AMP19 is a swappable amplifier card for the iBasso DX340, bringing genuine vacuum tube character and high current Class A power into a single portable module. Two distinct output modes allow the sound to be shaped to preference.

The AMP19 uses the sixth generation Nutube 6P1 triode vacuum tube, jointly developed by Korg and Noritake. It brings the renowned sonic character of traditional tubes to a portable player, warm and natural with emotionally engaging vocals, while being far better suited to stable, long term portable use. The Nutube 6P1 offers over 30,000 hours of lifespan, power consumption just 2% of traditional tubes, and a size approximately 30% of traditional tubes.

The AMP19 packs two entirely different amplifier paths into its compact size. In Tube Mode the Nutube 6P1 acts as the preamp tube, injecting harmonic richness for a warmer, more relaxed, natural tone. Vocals and instruments take on softer textures, with a more analog feel and a charming glow.

Super Class A Mode is a fully discrete amplifier built from 20 dual transistors, capable of up to 2A current output. That abundant current reserve delivers powerful energy, fast transient response, fuller sound, and excellent vocal density and texture.

The AMP19 uses a nationally patented 12V DC-IN external power technology. With an external DC source connected, the headphone amp supply is boosted from ±6.5V to ±12V, reaching 2150mW + 2150mW @ 32Ω, enough to effortlessly drive virtually any flagship headphone. Portable in form, but with driving power comparable to a desktop unit. Patent no. ZL 2025 1 0707956.3.

In Tube Mode the AMP19 uses JRC hardware volume control, adjusting output level by an analog method so the DAC signal stays fully intact, with no digital volume attenuation and no loss of fidelity. It effectively reduces output noise at low volumes, preserving clear, detailed sound and full layering even at quiet listening levels, with 100 fine volume steps for precise control of sensitive IEMs or high impedance headphones.

Every AMP19 is tested on the Audio Precision APx555 analyzer before shipment, then calibrated and matched by hand, with engineers using four hardware multi turn potentiometers to ensure consistent Nutube 6P1 operation. The result preserves the natural, delicate, layered sound of the tube with authentic analog flavour. Using the AMP19 requires updating the DX340 firmware to V1.08 or above.

After extensive experimentation, iBasso adopted a hanging installation method using PORON material to suspend the tube within the chassis, effectively absorbing shock and significantly suppressing the microphonic effect that plagues portable tube designs.