The Aroma Audio A100 is breathed from the concept the A10. The A100 provides a new experience in the field of portable amplifiers due to its amazing capabilities. For popular portable players, the A100 features a 2.5mm balanced input and a 3.5mm single-ended input, allowing you to take advantage of a variety of player features. The output terminal of the A100 is equipped with a 2.5mm balanced, 3.5mm single-ended, 4.4.mm balanced & single-ended integrated terminal. It also has a gain-switching function so that it can be utilised with various headphones/earphones.The A100 circuit design can be broadly divided into a power supply unit and an amplification unit. Power is the "mother" of the sound.The power circuit of the A100 accounts for two-thirds of the total space. It has a built-in step-up circuit that uses a specially designed battery with ultra-low internal resistance, a high-power MOS tube and an inductor (obtains ± 15 V with a boost of 600 kHz switching frequency). After the two CL filter circuits, a 4700 μF ultra-low impedance electrolytic capacitor is inserted, which provides high-quality power to the entire machine. One ± 15V channel is powered by an ultra-low ripple precision LDO (Low Loss Linear Regulator) for each cell IC, while the other ± 15V channel is directly powered by a triode discrete stage circuit supply. The A100 preamplifier circuit inherits the circuit design of the A10 and has a two-stage inverter amplifier circuit, but functionally this means that a balanced signal input has been added. The rear stage amplifier is a four-channel amplifier circuit that consists of a discrete transistor circuit, four pairs of middle power transistors, and a number of precision components, and provides a delicate yet powerful output to headphones.
The A100 does not adopt a fully balanced design as the power consumption will increase dramatically. In addition, four dual operational amplifiers are required, which takes up a lot of space. Using four dual op amps would save space but using eight single op amps would require more space and strains the power supply. Using a fully balanced design that reduces space and power requirements would result in poor performance.
For those who want to replace the op amp, the A100 inherits the design of the A10 quick-release replacement op amp. The case structure of the A100 has been redesigned. By removing the upper slide cover and locking the spring thimble, the replacement of the operational amplifier is extremely simple and the appearance has become even more beautiful.
The A100 has a battery level display on the side. Pressing the button will illuminate 25%, 50%, 75%, 100% LEDs from left to right according to the battery level.