What Problems FA2 Solve
We know that the current output stage of a general amplifier consists of two amplification lines: one line handles the negative (negative half cycle) output signal, and the other tube processes the positive polarity (positive half cycle) output signal. This can minimize the quiescent current, but to drive 8~600 ohm headphones, it must have a large amplitude of voltage and current; there are 4 or 8 tube portable players on the market, but not working in Class A,There may be some distortion, called cross distortion. It appears at or near the zero crossing of the output signal. If the two branches of the circuit do not match exactly, crossover distortion often occurs. FA2 completely solved the above two problems and shared the circuit architecture: the digital receiver of FA2 adopts AK4497EQ DAC Chip, IV - Ti(BB) OPA1632-Fully Differential I/O Audio Amplifierr; OP adopts OPA1612 (bipolar-input operational amplifiers-completely independent circuitry for lowest crosstalk and freedom from interactions between channels, even when overdriven or overloaded.), Toshiba 8-pair tube current amplification; among them, OP level (voltage, current amplification stage) adopts differential balanced output and works in Class A state; From DAC output to Toshiba 8-tube full direct coupling mode, ensuring high fidelity, High signal-to-noise ratio (FA1 signal-to-noise ratio (121db)), good dynamics without distortion; with good headphones, experience music playback in depth;
Key Features
DAC Chip: AKM high-End DAC AK4497EQ. Toshiba high-fidelity 8-pair tube-type balanced amplifier circuit. Fully differential balanced amplifier TI (BB) OPA1632. Voltage amplifier dual op amp OPA1612 (class A). Supports more audio format, including Apple lossless audio format--m4a, aac, ogg; audio formats such as mp3, wma, DSD( dsf&dff up to DSD256); ape, flac 0~8 compression ratio ; Hard decoding ape (24bit, three levels of compression mode), wav (up to 32bit), flac (24bit, 0-8 level). FA2 Comes with Built-in EMMC high-speed memory chip, and can also support up to 512GB Extension Memory card (supporting exFAT or FAT32 file system). More functions support: Auto power off, Sleep-off, Favorites, EQ (HiFi mode is recommended), Fast forward mode , Return key customization (long press - screen ff or long press- return to the menu), Turntable customization (quick selection Or volume), Folder cycle, Car mode, multi-level Directory Management. Professional audio processing DSP chip, better control, which is not a single-chip STMF4 or STMF7 microcontroller can compare to. Continuous play for 9 hours under comprehensive test circumstance. Support car mode; (automatic booting after car start, automatic shutdown after stop). Battery with Polymer, high density, high temperature resistance, 4000ma 14.8Wh
Technical Details
270mw (3.5mm Stereo,@32ohm), 320mw (3.5mm Balance@32ohm );
200mw (3.5mm Stereo,@150ohm), 170mw (3.5mm Balance@150ohm );
- 1 x F.Audio FA2
- User Manual