• Fully discrete NFCA also create wonderful amp TOPPING A90D uses fully discrete components to redesign the NFCA (Nested Feedback Composite Amplifier)module. 4 built-in NFCA-Discrete modules which each them uses 39 transistors build up fully balanced structure. The optimized Voltage Current hybrid feedback architecture along with UHGF (Ultra High Gain Feedback) technology provide excellent DC and AC performance.
• High output voltage, high current, low output impedance, no headphones that can't be dealt withHigh output voltage can easily drive high impedance headphones; High output current allows low-sensitivity headphones to obtain enough power; The low output impedance will not bring unnecessary effect on FR when driving low-impedance headphones. Different headphones can be easily driven by the A90 Discrete.
• 2 Gain settings TOPPING A90 Discrete has two gain options, which are 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 lEMs will not suffer from any noise.
• Ground Loop Noise Terminator Ground loop noise may be encountered when multiple devices are used in combination. 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 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.