Fully Discrete NFCA As its name, A90 Discrete features fully discrete components to redesign the NFCA (Nested Feedback Composite Amplifier) module. There are 4 built-in NFCA-Discrete modules building up fully balanced structure with 39 transistors. The optimized Voltage Current hybrid feedback architecture along with UHGF (Ultra High Gain Feedback) technology provide excellent DC and AC performance. Benefiting from the new design, its output capability is stronger than ever, which allows the amp driving low impedance headphones even more effortlessly. The unparalleled distortion and noise performance are ensured because of the paralleled ultra-low noise precision matched transistors in the design. Two Gain Settings The A90 Discrete has two gain options, which enough to cover a wide variety of headphones: low gain to drive the IEMs with high sensitivity, and high gain to drive full-sized over-ears. Combined with the 0.2uVrms ultra-low noise, even sensitive IEMs will not suffer from any noise. Ground Loop Noise Terminator Ground loop noise may be encountered when multiple devices are used in combination. Topping A90 Discrete adds a GND/LIFT switch to solve this problem. When in normal use, set it to GND; and when ground loop noise is encountered, switch it to LIFT. Then the ground loop noise is eliminated. A Headphone Amp, also a Preamp The A90 Discrete is not only able to drive the headphones but also served as a preamp. When it is in preamp mode, you can get the same high performance as the headphone amp mode, and the 20ohm SE and 40ohm balanced output impedance are widely suitable for various power amplifiers. A90 Discrete can not only switch between the headphone amp (only output from the headphone jack) and the preamp (only output from RCA and XLR), but also support the output from all at the same time. The full-featured remote control makes it more convenient for you. Customize Volume Control A90 Discrete characterizes a R2R volume control composed of relays and resistor networks, which brings the advantages of precise Control, longevity, complete channel balanced and remote control. According to the customized settings, a safe volume can beset to avoid sudden loud sound after power on/input switch. A90 Discrete can also set to memorizes both the output volume and the input volume.
