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QA390 Movable Desktop Player

A truly all-in-one machine

A truly movable all-in-one desktop player

Real: no front end, no connection line, no need to plug in, no need to toss around, no need to match other, not affected by the electrical environment

Movable: Built-in 13200mAh battery-powered system that is immune to external factors

Desktop: A set of isolated regenerative power supplies are generated from batteries. The internal current and voltage are designed according to the standards of high-end desktops.

All-in-one: Realize the complete integration from the power + player + decoder + amp, all the connections and collocations are done internally and done well, maximize the design and tuning of each part, realize 1+1+1 +1>4 effect, let users really hear the good sound we want everyone to hear

Really made 1+1+1+1>4

1. A truly mobile all-in-one machine designed with a large-capacity battery and a current and voltage in the machine according to the standards of high-end desktops.
2. Double 1000000uF low internal resistance super capacitor blessing for digital and analog part of the isolated power supply, similar to the desktop dual transformer design.
3. The balanced amp can output more than 20V, which is convenient for driving high-impedance headphones.
4. The final stage power tube current output capability is 2700mA, which promotes the low-impedance low-sensitivity headphones.
5. The DAC chip uses AK4497EQ × 2 and supports ALL To DSD.
6. Two femtosecond crystal designs, high-speed precision-controlled CPLD clock processing, and global unified clock and synchronous operation modes.
7. Built-in single-chip single-threaded SD card pure music player.
8. HWA (LHDC) HD Bluetooth input for easy connection to mobile phones.
9. Two-way USB interface, all the way to the phone or tablet (no camera kit required), all the way to the Italian interface to access the computer.
10. Four 3300mAh Panasonic (formerly Sanyo) 18650 batteries provide a total battery capacity of 13200mAh.
11. More than 30 ultra-low noise power chips provide a clean enough power for each circuit device.
12. Headphone port is complete, single-ended: 3.5, 6.35; balanced: 2.5, 3.5, 4.4, XLR.

Power supply is the mother of sound

The high-precision clock that digital audio relies on also depends on a sufficiently clean power supply.

Power circuit design that is lower than battery noise

For the power supply of digital circuits, the battery is not clean enough. In order to solve this problem, we use a lot of LT3045 chips with much lower noise than the battery in QA390, completely eliminating interference from power supply.

The noise of this chip is only 0.8μVRMS, which is much lower than the noise when the battery is working (the noise is about 2.7uV when the 3.7V lithium battery has a 500mA load). At the same time, the chip has a low frequency of nearly 100dB and a high of 76dB at 1MHz. The power supply ripple rejection capability eliminates interference from power supplies.

Always insist on the tuning concept of the power supply as the mother of sound

More than 30 ultra-low noise power chips provide a clean enough power for each circuit device

Completely different from the battery circuit of the portable

Most of the batteries used in portable players are limited to 2 ~ 3A, which makes the sound scale, dynamic and momentum less natural than desktop players. The battery used in the QA390 can achieve a single discharge current of 10A, and we use multiple parallels to further reduce the internal resistance while the current capability is several times. This current explosive force exceeds many machines that use 220V power supply.

In addition, the analog and digital inlets of the power supply circuit each have a 1000000uF super capacitor, which provides further protection for the instantaneous current. The built-in very good power supply system is the basis of its good sound.

Can be used as a relative reference standard for ideal sound

Unconstrained by the volume, the battery generates a set of desktop-level isolated regenerative power supply, which solves the problem that the traditional AC power supply is affected by the power environment, making the sound more stable and stable, so that all users can hear the sound we want to express.

The QA390's battery-powered sound is largely unaffected by any external factors and is ideal as a relative reference for good sound.

Two super capacitors, supplemented by multiple isolated ultra-low noise power circuits

Dual 1000000uF low internal resistance super capacitor support for digital and analog partial isolation power supply, similar to desktop dual transformer design

Double femtosecond crystal design

High-speed accurate timing control of CPLD clock processing and digital audio signal optimization

Global unified clock and synchronous working mode

Seriously and rigorously treat the most important power supply that affects the clock, reduce interference, ensure accuracy, and ensure that the playback system is synchronized with a very high quality clock.

Referring to the dCS monolithic clock synchronization supply design, the global source comes from the dual femtosecond clock, which is equivalent to the clock synchronization function between the audio and the DAC.

DAC chip uses AK4497EQ x 2

ALL To DSD mode, Listen more than CD

The following square wave output analysis is the measured figure.

By the comparison of the above measured wave forms, we can find that ALL To DSD is more purified and has less harmonic distortion than the original PCM direct output signal.

A truly all-in-one player

Current and voltage are designed to high-end desktop level standards

Balanced amp can output more than 20V, push high-impedance headphones handy
The final stage power tube current output capability is 2700mA, which promotes the low-impedance low-sensitivity headphones.

11 selected op amps in the analog section + 8 dual-current transistors provide high-density, Delicate, Open, Imposing Sound

Programmable analog potentiometer volume control solves left and right imbalance and digital loss

Dual firmware switching mode, Tuning style is bright and mellow

Power management mode: The digital output can be turned off, the output of the LINE OUT module can be turned off, the output of the front stage can be turned off, or the output of the amp can be turned off. The Bluetooth and USB are only powered when they are used.

Isolation and shielding design of high frequency interference between modules

In order to continuously improve the sound quality and performance of the product, the materials or wiring are subject to change without notice.

Full CNC aluminum housing, partition shielding design

Optimized design of traces inside the system, isolation and shielding design of high-frequency interference between modules, digital and analog isolation design on the chassis, and partition shielding design in the entire CNC aluminum enclosure, which greatly reduce EMI interference.

     Product Positioning

1. Don't care about volume and weight, the pursuit of sound is uncompromising, and you want to experience the sound quality of a large machine on a mobile machine.
2. Frequent business trips, participation in various parties, events, offices, homes, study, living room, bedside and other enthusiasts with mobile needs.
3. A user who wants to go out with a big headphone.
4. Use on the desktop, want to push the big headphones more easily and get a good voice.
5. High-end desktop users who don't want to invest too much money to toss around the wire, electricity, etc., and want to get good sound quality.
6. Very good sound quality desktop unit, can replace your front-end source, can be directly connected to the active speakers or connected to the amplifier to drive passive speakers.
7. The digital and analog outputs are first-class, can be used as a digital turntable or decoded to meet the high sound quality requirements of multiple scenes.
8. The following scenario:
     (a) If you have invested a lot of money in your desktop system power supply and wire matching, but the sound is still not satisfactory, I suggest you try the battery-powered QA390, its sound can at least give you a reference.
     (b) If your desktop system is sometimes nice, sometimes not good, one sound during the day, another sound in the middle of the night, or a good period of time and not good for a while, it proves that the electrical environment has a great influence on the sound of your system, completely immune to electricity. The QA390 for environmental impact must be tried.

    Application scenario

QA390 is widely used and is not limited to the above applications. More applications can be consulted by technicians.

• Internal playback storage media: use an external SD card or TF card plus card sleeve in FAT32 format, currently supports a maximum capacity of 512GB
• Internal playback support: 16 - 32Bit, 44.1KHz ~ 352.8KHz, DSD64 ~ DSD128.
• USB interface - USB B port: use the authorized Italian interface Combo 384, support 32Bit / 384KHz PCM and DSD256
• USB interface--Micro port: use SA9227 interface, Apple phone and tablet do not need camera kit, support 32Bit / 384KHz PCM and DSD128
• Bluetooth: Supports Bluetooth 5.0, supports Huawei HD Bluetooth HWA（LHDC) and AAC encoding
• Coaxial input: 75Ω matched impedance, support 24Bit / 192KHz and DSD64(DoP)
• Optical Input: Supports 24Bit / 192KHz and DSD64（DoP)
• Coaxial output: 0.5Vp - p75Ω, support 24Bit / 192KHz and DSD64(DoP)
• Optical output: support 24Bit / 192KHz and DSD64(DoP)
• Analog output:
    Frequency response: 20-20KHz
    S / N: 122dB
    Dynamic range: 121dB
    Stereo Crosstalk：120dB
    THD+N：0.0005%
• Output level:
    RCA (L&R) 2.5V (closed pre-amp)
    XLR (L&R) 5.0V (closed pre-amp)
    SE (Unbalanced)maximum 10.5Vrms(High amp voltage, Ultra high gain, 600Ω load)
    BAL(Balance)Maximum 21Vrms（high amp voltage, ultra high gain, 600Ω load)
• Headphone matching impedance: 8Ω - 600Ω
• DAC: AK4497EQ x 2, LPF: AD797 x 2
• Volume control (including preamp volume control): PGA2311UA
• Reference clock jitter: 0.088 picoseconds (88 femtoseconds)
• Charging port: Available Type-C port, DC port available, QC2.0 quick charge.
• External power supply: DC 5.5*2.1 port, can also be charged (panel switch selection)
• Life time: 8~10 hours (depending on settings, music format, load condition) (measured engineering machine, balance port directly pushes 600 ohm T1, volume 30, digital output off, analog output amp, sound mode descent High gain, high amp voltage, automatic off screen: 30 seconds, 16Bit / 44.1KHz WAV file full card random play, battery life 10 hours and 10 minutes)
• Charging time: Type-C common charge: 8 ~ 9 hours, Type-C fast charge / DC port: 4 ~ 5 hours
• Host & Remote Control Material: All-aluminum CNC integrated milling
• Product weight: 3.0kg in full package, net weight 1.8kg
• Machine size: 20cm x 18cm x 4.45cm, Packing size: 33cm x 27cm x 9cm

Single-ended headphone port rated output power

32Ω	300Ω	600Ω
1000mW / ch	360mW / ch	180mW / ch
High amp voltage and high gain	High amp voltage and supper high gain	High amp voltage and supper high gain

Balance headphone port rated output power

32Ω	300Ω	600Ω
1300mW / ch	1200mW / ch	720mW / ch
Medium amp voltage and supper high gain	High amp voltage and supper high gain	High amp voltage and supper high gain

1. QA390 Player x 1
2. 64GB TF card (with card holder)  or SD card  x 1
3. USB3.0 card reader x 1
4. USB A port to B port USB cable x 1
5. TYPE-C charging cable x 1
6. External power supply (can be used for charging) x 1
7. Infrared remote control x 1

Note: The USB cable connected to the mobile phone is not standard. If you need a friend, please contact customer service to purchase.