QA350 MOD V2 is new mod version of QA350, It upgraded the headphone amp chip MAX9722A to AD8397 chip, It sounds damn good. It has the capability to drive any headphones available in the high-end with ease.
QA350 MOD V2 has a very large output power:
QA350 Output Power: 70mW/16Ω; 130mW/32Ω; 26mW/150Ω; 13mW/300Ω;
QA350 MOD V2 Output Power: 500mW/16Ω; 250mW/32Ω; 97mW/150Ω; 49mW/300Ω;
Relative QA350, QA350 MOD V2 sound is much better, Very powerful bass, Good timbre, Good soundstage, It has very nice dynamics,ruler-flat frequency response; distortion levels very low.
QA350 MOD V2 use good audio capacitors: Nichicon MUSE MP、Nichicon SILMIC、Panasonic FM、ELNA、Sanyo Poscap....
QA350 and QA350 MOD V2 internal PCB board comparison:
(In order to improve the quality and sound quality, components are subject to change without notice.)
QA350 is a WAV high fidelity music player designed and made by QLS Electronics. SD card is applied as storage medium while lossless WAV format as the sound source. The player integrates DAC and headphone Amplifier circuit with the built-in high-capacity rechargeable lithium polymer battery. It is convenient to carry with and play music.
QA350 retains the optical and coaxial digital output of QA-550, while increases the analog (LINE OUT) output (which can be directly connected to your amplifier or pre-level) and the amp output, which can drive the majority of 16-300Ω headsets.
More professional components, more rigorous screening mechanism of components, more stringent design layout, more rigorous testing and debugging are applied in QA350. Users are allowed to fully experience an unparalleled listening enjoyment brought about by the player.
- Use 2PPM 11.2896 TCXO Crystal (crystal JITTER is below 10PS)
- The power supply part use several LDO, respectively offer power for: crystal oscillator, the main chip, the digital output chip, DAC digital, DAC analog, headphone amplifier, display control, to ensure the best sound quality.
- In portable system, fever grade materials are applied: Kemet tantalum capacitors, YAGEO SMD 1% precision resistors, high precision SMD capacitor of Samsung, ELNA electrolytic capacitors, ALPS potentiometer.
- Lithium polymer battery of general specifications applied in the aircraft models serves for power supply. The benefits are:
- Discharge in large rate and low internal resistance. Discharge current can reach couples of Ampere in a blink to increase the low frequency and transient explosive power of portable system.
- Lithium polymer batteries applied in the aircraft models have common specifications and are easy to buy which facilitate users to replace batteries by themselves. (Batteries have certain usage life. Customized size / appearance bring great inconvenience to users for the subsequent replacement of the battery.) (Maximum supports of 55mm * 31mm * 16mm 7.4V lithium battery for model aircraft are available).
- Model aircraft batteries commonly use high-quality battery cells and have enough stock and market verification for long time with stable performance and long service life.
- Provide a professional balance charger for models for the rechargeable lithium balance charge, which reduces the charging time, and expands long battery life.
- Onboard short-circuits protection and over-discharge protection ensures the battery life.
- QA350 directly applies 7.4V lithium battery. we spent a lot of time selecting high-end chip OPA and the OPA with good performance under low voltage. The whole player has no step-up circuit and reverse voltage circuit. The sound is transparent and pure.
- LDO filter circuit strictly matches ESR to ensure minimum ripple output.
- Firmware can be upgraded, and the upgrade is simple.
- Provide external power input interface, and the input voltage is DC9V-DC12V. When external power is input, the internal power supply will be automatically disconnected.
- When the internal battery is charging, external power supply is available. (We are not recommended to use battery offer power supply When the charging internal battery, which have significant impact on battery life).
Product specifications Indicators:
- Play format: 16bit 44.1K WAV (the same with CD ripping and file format).
- Storage method: SD card storage media is applied for audio playback, FAT32 format less than (equal to) 32G, SD/SDHC), SD card support hot swap.
Support maximum 90 folders with the maximum of 900 songs; the remote control can directly select the folder or directly input the track number. The operation is very convenient.
- Digital output chip: CS8406.
- DAC Chip: Wolfson WM8740.
- LVP: AD8656.
- Headphone Amp chip: AD8397.
- Digital Output: Coaxial (RCA), Fiber Optical (round).
- Analog Output: LINE OUT, headphone AMP output.
- LINE OUT parameters: level 2V (RMS); frequency response 20hz-20Khz. SNR> 100dB; Distortion <0.005%.
- Headphone amp out parameters: 500mW/16Ω; 250mW/32Ω; 97mW/150Ω; 49mW/300Ω; Frequency response: 20 Hz-20Khz; THD + N (total harmonic distortion plus noise): 0.008%.
- Headphone output matching impedance: 16 ohm --- 300 ohm
- Battery Type: 7.4V Li-Po battery of Model General Specifications, maximum size: 55mm * 31mm * 16mm; the capacity is usually among 800-1100mAH.
- Battery life: 5 to 7 hours.
- Charging time: 1.5-3 hours (when charging, playing music can available powered by the external power supply)
- Power consumption: 150mA-180mA (LCD backlight does not open) or 200-300mA (open LCD backlight)
- Specifications of matching charger: Support 2 cells Li-Po batterys balance charger.
Supply Voltage: 110-240V AC.
Maximum charge current: 800mA. Display: double-color LED instructions of charging charge status.
- Dimension: 135mm * 78mm * 27mm (excluding the output socket, switch, button, etc.)
150mm * 78mm * 30mm (with all the sockets, VR button, switch, button)
- Package size: 235mm * 135mm * 55mm
- Single Weight (with battery): 0.3kg
- Packing Weight: 0.75kg
WAV files are the favourite format choice of people who can't bear the sonic difficiencies of the lossy compressed MP3 format yet want to store, preserve and playback treasured CD collections from their computer hard disk drives.
Up until now, these people would simply be content to use their computer as their main Hi-Fi source component.
Whilst excellent at converting CDs to WAV files, the PC / Mac is still not the ideal music plackback device. The majority if PCs don't have the best powersupplies and are absolutly packed with noisy, interference inducing components. Multiple noisy fans buzz away constantly and due to components fighting over limited resources, "pops" and stutters on the audio are not uncommon.
In these days of hugely expensive utility bills, the electricity consumed in putting a computer to use for considerable periods just for music playback is also quite considerable as is wear and tear to the hardisks.
Reasons why the QA-350 is a better music transport than a PC...
- Silent (no moving parts)
- Powered by dedicated 9v dc linear power supply or battery. Helps reduce jitter
- No pops stutters or audio glitches (assuming that WAVs were extracted with love by EAC)
- Uses nowhere near the amount of energy that a PC needs
- Far more compact than even the smallest laptop PC
- Useful remote control functionality