Advanced Circuit Design
The AMP13 completes voltage amplification through the vacuum Nutube, giving AMP13 an engaging sound, all while delivering excellent linearity. At the same time, the Nutube achieves substantial power saving, miniaturization, and quality improvements when compared with a conventional vacuum tube. However, two stages of amplification are necessary to obtain higher output power. To have both a more robust 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 - AMP13 utilizes Nutube 6P1 as a voltage amplifier. This is followed by digital volume control and current amplification. The low noise tube output is the output after the first amplification stage. Although the output is not high using this design, the Nutube has a more robust 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, resulting in better driving capability for headphones and IEMs. (4.1Vrms)
Although the Nutube 6P1 has the same characteristically rich overtones as conventional triode vacuum tubes, its low output capability, and poorer noise control have always been a design problem. The single-ended output of ordinary players generally only has left and right dual-channel amplification. On the AMP13, iBasso uses three-channel amplification. Utilizing the OPA1622 to amplify the output ground signal, the noise floor is dropped substantially while enhancing dynamics and improving the Nutube performance. The AMP section of the DX320/DX300 has its own battery power, which is perfect for the AMP13 because it 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.
Hand Matched so each 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 together a clean, extended upper frequency and a sweet and engaging sound for your musical enjoyment.
