Photos and specs Stereo amplifier FiiO A1

Description stereo amplifier, FiiO A1

Stereo amplifier FiiO A1 is made in a small metal case, and works in the economical class D. the Unit develops an output capacity of 2 x 14 W designed for connecting a small speaker system with a standard impedance of 4 to 8 Ohms.

Cascades pre-amp, FiiO A1 is made on the basis of a low noise operational amplifiers OPA2134 from Texas Instruments and provides a minimal level of distortion and high slew rate. Adaptive negative feedback, the depth of which varies in accordance with changes in the level of the input signal, allows to obtain very good sound quality with stable circuit operation. Output stages are based on NPX chip TFA9815T with balanced output (BTL), which provides a high output current at low supply voltage. A feature of this apparatus is that the amplifiers for each channel operate at different carrier frequencies (550 and 600 kHz), which ensures no crosstalk. To adjust the volume in the FiiO A1 is used indoor dual variable resistor Alps of high class, combined with the power switch.

The amplifier has two line inputs, one of which is represented by RCA, and the other mini jack. When included in the socket of the interconnect cable, RCA-input is disabled. For connecting speaker systems are two pairs of robust binding posts. The device is powered from an external mains unit providing 12 Volts at a current of 3.5 amps.

Amplifier FiiO A1 is equipped with multi-level protection system, triggered when overheated, a short circuit in the load, excessive raising or lowering of the supply voltage. The phone provides very good sound quality and at quite sensitive acoustics can sound the room is medium in size. In addition, FiiO A1 it is expedient to use together with monitors near zone, for example, when connecting to PC and placing the speakers directly on the desktop.

Features stereo amplifier, FiiO A1:

In the section of the preamp chip used Texas Instruments OPA2134, having excellent noise characteristics, low distortion and rapid growth of the signal
Scheme amplifier built on a chip from NXP TFA9815T working in class D
Amplifiers each channel operate at different carrier frequencies (500 kHz / 600 kHz), which contributes to better insulation of the channels and reduction of interference
The device is activated and deactivated by turning the volume control, which is a high quality potentiometer from APLS
You can choose the most convenient audio input: minijack 3.5 mm or RCA (minijack has the higher priority: if you connect a FiiO A1 via this input, the RCA input is automatically disabled)
The minimum impedance is 4 Ohms
The connectors for acoustic systems of type "banana" will allow you to connect any speakers

Features stereo amplifier, FiiO A1