Topping A90 Discrete Balanced Headphone Amplifier

As its name, A90 Discrete uses fully discrete components to redesign the NFCA (Nested Feedback Composite Amplifier) stage.

Four integrated NFCA-Discrete modules which each use 39 transistors in a fully balanced structure.

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, the output capability is stronger than ever, which allows the amp driving high impedance headphones even more effortlessly. The paralleled ultra-low noise matched transistors in the design, ensures a rich and clear sound, low noise and distortion.

High output voltage, high current, low output impedance, the A90 Discrete can drive high impedance and low sensitivity headphone.

Two gain settings

The A90 Discrete has two gain options, and therefore can deal with a wide variety of headphones: low gain to drive IEMs with high sensitivity, and high gain to drive demanding full-sized over-ears headphones. Combined with the 0.2µVrms 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.

The A90 Discrete adds a GND/LIFT switch to solve this problem. When in normal use, send it to GND; and when ground loop is encountered, switch it to LIFT. Then, the ground loop noise is eliminated.

Headphone Amplifier, also a Preamplifier

The A90 Discrete is not only able to drive the headphones, but also serves ad a preamp.

When it’s in preamp mode, you can get the same high performance as in headphone amplifier mode, and the single-ended 20 Ohm and balanced  40 Ohm output impedance are widely suitable for various power amplifiers.

The A90 Discrete not only can switch between the headphone amp (only output from the headphone jack) and the dream (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 to use.

12V Trigger

The A90 Discrete is equipped with a 12V trigger interface, which can be set as an active control (trigger out), or passive control (Trigger in). This way, the A90 Discrete can be turned on and of synchronously with other devices equipped with a 12V trigger interface.

Custom volume control

The A90 Discrete uses a R2R volume control composed of relays and resistor networks, brings the advantages of precise control, longevity, complete channel balanced and remote control.

*** The A90 Discrete provides you 1 x XLR and 1 x RCA stereo inputs, but when combined with a Topping EXT90, they could provide 4 x XLR and 2 x RCA stereo inputs.

In the box: