QLS QA390 AK4497EQ Bluetooth 5.0 HiFi Lossless Desktop Music Player DAC Decoder Headphone Amplifier
A truly portable desktop all-in-one machine
No need the front end, do not need to connect the wire, no need to plug in, no need to toss about peripheral equipment, no need to match other, no need to be affected by the electrical environment.
Built-in 13200mAh battery power system no affected by external factors.
The battery is used to generate a set of isolated renewable power sources at the desktop level. The current and voltage in the machine are designed according to the standards of the desktop.
To achieve the complete integration from power supply + player + decoder + headphone amplifier, all the connections and collocation are done and completed in the internal, through each part of the design and tuning to maximize the effect of 1+1+1+1>4, let users really hear the good sound that we want everyone to hear.
Electricity is the mother of sound
The high-precision clocks that digital audio relies on also depend on enough clean electricity
design with lower noise than battery
Due to the power supply of digital circuits, the battery is not clean enough. To solve this problem, we used multiple LT3045 chips with much lower noise than the battery in the QA390 to completely eliminate the interference from the power supply.
The noise of this chip is only 0.8vrms, which is far lower than the noise of the battery (about 2.7v for a 3.7v lithium battery with a 500mA load). At the same time, when the low frequency band is nearly 100dB and 1MHz, the chip also has an ultra-high power source wave suppression capacity of 76dB, which can eliminate interference from the power supply.
Ultra-low noise LDO: LT3045*6, ADM7170*2, LP5907*3, ADP151*8, TPS79101*4, ADP7182*2
High speed low noise LDO: XC6204*3
Low noise LDO: LP2985*1, LM27762*1
DC-DC converter: ADP2108*2, TPS61087*3, LT3757*1, LM2665*1
different from portable battery devices
Most of the batteries used in portable players are limited to discharge current of 2-3A, which makes the scale, dynamics and momentum of the sound inherently inferior to that of desktop machines. The single discharge current of the QA390 battery can reach 10A, and we use multiple batteries in parallel to further reduce the internal resistance. At the same time, the current capacity has reached several times. This current has more explosive power than many machines using 220V power supply.
In addition, the analog and digital 1000000μF supercapacitors at the entrance of the power circuit provide further protection for instantaneous current. The built-in very good power supply system is the foundation of its good sound.
Can be used as a
relative reference standard for ideal good sound
Not limited by volume, using a battery to generate a set of stand-alone isolated regenerative power sources, solving the problem of the traditional AC power source sound is greatly affected by the power environment, making the sound more stable and stable, so that all users can hear what we want The voice of expression.
QA390's battery-powered sound is basically unaffected by any external factors, and it is ideal as a relative reference standard for good sound.
1. Four 300mAh Panasonic 18650 batteries provide a total battery capacity of 13200mAh.
2. Four-way fast charging chip is used to charge each battery independently, and Linear ideal diode + ultra-low internal resistance MOS tube is used for discharge management to ensure sound quality.
3. The player can be charged with the mobile phone charger (including quick charge) or the charging bank, which is convenient to use.
4. Perfect battery over charge, over discharge, overcurrent, short-circuit and over temperature protection circuit to ensure safe use.
capacitors, supplemented by multiple isolated ultra-low noise power circuits,
is equivalent to using multiple transformers
Dual 1000000μF low internal resistance supercapacitors provide isolated power supply for the digital and analog parts, similar to the dual transformers design of the desktop.
High-speed CPLD clock processing with precise timing control and digital audio signal optimization processing.
Global clock unified
and synchronous working mode
Carefully and rigorously treat the most important power supply affecting the clock, reduce interference, ensure accuracy, and ensure that the playback system uses a very high-quality clock synchronously throughout the process.
With reference to the DCS single-unit synchronous supply design, the global source is the dual femtosecond clock, which is equivalent to the clock synchronization function between the audio source and the DAC.
Using 2 AK4497EQ
decoding chips, ALL To DSD mode, hear more than CD
ALL To DSD mode can upgrade all formats to 1Bit 5.6448MHz and DSD128 high resolution of twice SACD, even the PCM of the original signal.
True all-in-one machines, current and voltage are designed to desktop-level standards
Balance amplifier can output more than 20V, driving high resistance earphones handy. The current output capacity of the final power tube is 2700mA, which pushes the earphones with low resistance and low sensitivity with full momentum.
Simulation section, with 11 selected operational amplifier +8 dual large current transistors
Provide high density, fine, opening, imposing voice.
Programmable analog potentiometer volume control to resolve left - right imbalance and digital loss
Lossless analog volume adjustment to ensure good sound quality for small volumes: wide range of adjustment, fine adjustment process, left and right channel almost complete balance, thus achieving a wide range of accurate control of volume.
In pursuit of the good voice, the QA390 uses the more expensive and less distorted PGA2311UA instead of PGA2311U.
Linear read music
data, making the background of the sound in very dark
Single-chip microcomputer is still used to linear read music data to ensure the real-time performance of audio data forwarding.
switching mode, tuning style optional, elegant and mellow
Power management mode: digital output can be turned off, LING OUT module output can be turned off, pre-amp output can be turned off, and amp output can also be turned off. Bluetooth and USB only turn on power when in use.
Full CNC aluminum
housing, inner partition shielding design
The optimized design of the internal wiring of the system, the isolation and shielding design of high-frequency interference between each module, the digital and analog isolation design on the case, and the partition shielding design of the entire CNC aluminum housing, all of which greatly reduce EMI interference.
The QA390 is widely used
Mobile phone USB/ Bluetooth connection
Computer USB connection
CD digital output
Connect various headphones
Output to various amplifiers
Digital output to the decoder
Analog output to the active speaker
Digital output to AV amplifier
Internal playing memory support: use an external SD card or TF card with a cover, TAT32format, support up to 512GB at present.
Internal playing support code rate: 16-32Bit, 44.1kHz-352.8kHz, DSD64-DSD128
USB interface-USB interface: use authorized Italy interface Combo384 and optimize hardware design, support 32Bit/384kHz PCM and DSD256
USB interface-Micro interface: use SA9227 interface, Apple phones and tablet PC needn’t camera suit, support 32Bit/384kHzPCM and DSD128
Bluetooth receive: support Bluetooth 5.0, support Huawei HD Bluetooth HWA(LHDC) and AAC coding
Coaxial input: match 75ohm impedance, support24Bit/192kHz and DSD64(DoP)
Optical input: support 24Bit/192kHz and DSD64(DoP)
Coaxial output: 0.5Vp-p75ohm, support 24Bit/192kHz and DSD64(DoP)
Optical output: support 24Bit/192kHz and DSD64(DoP)
Frequency response: 20-20kHz
Dynamic range: 121dB
RCA(L&R) 2.5V(close front pre-amp)
XLR(L&R) 5.0V(close front pre-amp)
SE(unbalance) max 10.5Vrms(amp voltage high, ultra-high gain, 600ohm load)
BAL(balance) max 21Vrms(amp voltage high, ultra-high gain, 600ohm load)
Amp output impedance: unbalance: 0.13ohm, balance: 0.2ohm
Earphones impedance: 8-600ohm
Decoding chip: AK4497EQ*2, LPF: AD797*2
Volume control(and pre-amp volume control): PGA2311UA analog program controlled volume
Reference clock jitter: 0.088ps(88fs)
Charge port: Type C and DC interface, support quick charge, compatible QC standard
External power supply: DC 5.5*2.1 interface, and charge(panel switch option)
Life time: 8-10 hours(depend on setting, music format, load condition)
Charge time: Type C common charge: 8-9 hours, Type C quick charge: 4-5 hours
Player and remote controller material: all aluminium CNC whole finish-milling
Weight: full package in 3.0kg, player in 1.8kg
Player size: 20cm*18cm*4.45cm
Single end earphones interface rated output power
32ohm, 1000mW/ch, amp voltage high, gain high
300ohm, 360mW/ch, amp voltage high, gain ultra-high
600ohm, 180mW/ch, amp voltage high, gain ultra-high
Balanced earphones interface rated output power
32ohm, 1300mW/ch, amp voltage medium, gain high
300ohm, 1200mW/ch, amp voltage high, gain ultra-high
600ohm, 720mW/ch, amp voltage high, gain ultra-high
Support audio formats
WAV: 64Bit/192kHz, 24Bit/352.8kHz(fixed point, floating point)
AIFF: 32Bit/192kHz, 24Bit/352.8kHz
FLAC: 24Bit/352.8kHz(level 0-8)
APE: C1000, C2000, C3000: 24Bit/192kHz; C4000: 24Bit/96kHz(fast/normal/high/ultra-high)
ALAC: 24Bit/48kHz(M4A container)
Wav Pack: 24Bit/48kHz (fast/normal/high)
DIFF: DSD64/DSD128 (not support DST decoding)
DSF: DSD64/DSD128 (not support DST decoding)
SACD-ISO: DSD64 (not support DST decoding)
MP3: 16Bit/48kHz, 96-320kbps(CBR/VBR/ABR decoding)
AAC: 16Bit/44.1kHz(M4A container, AAC LC/SBR decoding)
DTS: 16Bit/44.1kHz(WAV container, DTS-5.1/DTS-ES)
CUE: ANSI/Unicode/Unicode Big Endian/ UTF-8 decoding)
USB-PC input: PCM 32Bit/384kHz, DSD64/DSD128/DSD256
USB-phone input: PCM 32Bit/384kHz, DSD64/DSD128
Bluetooth input: PCM 24Bit/192kHz, SBC/AAC/HWA decoding
Coaxial/optical input: PCM 24Bit/192kHz, DSD64(DoP)
Coaxial/optical output: PCM 24Bit/192kHz, DSD64(DoP)
64GB TF card
USB 3.0 card reader
USB cable (A port to B port)
Type C charging cable
External power supplier (and charge)
Will be shipped via DHL/UPS/EMS/FEDEX .
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All listed items will be shipped though Registered Airmail with tracking number if there is no extra shipping method option listed or shipping description in the product page.
Economy shipping: Will be shipped without tracking number.
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It will be shipped via Hong Kong Post by default, Europe countries can choose to be shipped via Deutsche Post or Netherlands Post, it is also FREE, pls leave us a message if needed.
Express service: Will be shipped via DHL/EMS/UPS/FedEx