TOPPING A90 Full Balanced Headphone Amplifier XLR Pre-Amplifier
Topping challenges the whole market of headphone amplifiers with its A90 : an exceptional performance desktop headphone amplifier / preamplifier. With a SINAD up to 123dB (measured by Audio Science Review) on its balanced output and an incredibly low distortion of 0.000086%, the A90 significantly expands the boundaries of what most advanced home audio equipment can offer.
Balanced & single-ended connectivity
Topping A90 has a stereo balanced input XLR 3-pole and an single-ended input stereo RCA connector on its rear face . It offers a balanced (XLR) / single--ended (RCA) as preamplified output.
The connectors dedicated to the headphone amplifier are located on the front panel. A90 has all the connections necessary to easily connect headphones / IEM with various characteristics and requirements: a balanced output on XLR 4-pole connector, a second balanced output on jack TRRS 4.4mm connector Balanced headphone outputs are capable of delivering a power of 250mW and have an output impedance of 0135 Ω.
Finally tthe frontpanel offers an unbalanced output on 6.35mm connector with a power output of 125mW.
Volume control, source selection / outputs
The preamplifier / headphone amplifier A90 provides a volume control through a rotary knob directly accessible from its facade.
On its front side, three selectors allow easy control of all the device functions to immediately find the best configuration for your setup.
A first selector allows selecting the output mode and can switch between preamplifier mode and headset amplifier mode. These two modes can not be active simultaneously. This switch is also used to turn off the device.
A second bipolar selector serves as source selection and allows the user to select between balanced and single-ended input. It is therefore possible to connect two separate devices on each of these inputs and use the A90 as simple source selector.
The last selector is a gain control with three levels (low gain / medium gain / high gain) to get the best performance according to your sources and the type of headphones used.