[转贴]世界上第一台支持24bit/192KHz的便携式播放器,七彩虹Pocket HIFI来了

都市夜归人 · 发表于 2010-8-3 15:21

第一个能播放24BIT 192KHZ的便携播放器；
第一个抖动小于5皮秒的便携播放器；
第一台可以很好推动300欧姆耳机的便携播放器；

简要介绍一下

Colorfly pocket hifi is a customized product for the advanced audio. It supports most of the lossless audio format files and other compressed audio format files playback, Such as WAV,APE,FLAC,MP3,WMA.

It used advanced audio DAC chip(CS4398), The hight performance DAC support sample rates up to 192kHz and accept up to 24bit audio data. Colorfly pocket hifi built a sample rate conversion(SRC) module,It can greatly improve the performance of common audio formats,improve the sound quality.

It chose the TCXO used to reduce the clock jitter, It is be able to match the high-performance desktop audio device.It support SPDIF output, Provide high-performance digital audio output.

Colorfly pocket hifi may be one of the best portable hifi audio products.

支持各种音频格式，不过没看到M4A....

支持24/192格式，D/A采用CS4398，有耳机输出、RCA输出和光纤输出，jitter非常小

采用CS8422作为采样率转换芯片

http://www.cirrus.com/en/pubs/proDatasheet/CS8422_F1.pdf

1644到24192的动态范围是138DB，THD+N为133DB，相比CS4398的规格，可以认为是无损SRC

运放采用的是单个AD823，这个运放有意思的地方是电压非常宽，3v~36v都可以，最适合做这类设备的运放，可惜，usb声卡也好，随身听也好，以前根本没看到过这样的配置

http://www.analog.com/en/amplifi ... oducts/product.html

当然，价格过高是重要因素，3美金一颗啊，价格是某些厂商吹得天花乱坠的OP275的2倍哦，同时也比著名的OPA2132贵，而且似乎定位还不是音频的，成功案例多为中高端设备，比如SOLO耳放和NO.390S CD机

Single-supply operation
Output swings rail-to-rail
Input voltage range extends below ground
Single-supply capability from 3 V to 36 V
High load drive
Capacitive load drive of 500 pF, G = +1
Output current of 15 mA, 0.5 V from supplies
Low distortion: −108 dBc worst harmonic @ 20 kHz
Low noise: 16 nV/√Hz @ 10 kHz
Good dc performance
800 μV maximum input offset voltage
2 μV/°C offset voltage drift
25 pA maximum input bias current
Excellent ac performance on 2.6 mA/amplifier
−3 dB bandwidth of 16 MHz, G = +1
350 ns settling time to 0.01% (2 V step)
Slew rate of 22 V/μs
No phase inversion with inputs to the
supply rails
注意最后一条哦

ADI官方有3.3V的数据，比30V显然不足，但已经比大部分运放在低电压情况下要好不少

这个运放，ADI的定位是：

APPLICATIONS
Battery-powered precision instrumentation
Photodiode preamps
Active filters
12-bit to 16-bit data acquisition systems
Medical instrumentation

实际比一般音频应用层次要高

硬件配置：

ADI AD823 Op-Amp chip
CIRRUS LOGIC CS4398 DAC chip
ELNA SICMIC II BLACK GOLD VERSION HIFI capacitor
1% precision 0805 SMT resistor (Analog circuit)

Using Black PCB with 3U Immersion-Gold Technology
North American walnut or African rosewood housing
Aluminum polymer capacitors(Power circuit)

3U gold-plated RCA on SPDIF IN / OUT port
3U gold-plated on 6.3 headphone jack
AlPS PRO AUDIO mixer
Integrated C4 headphone-amp chip ,developped
by Colorfly and audio chip manufacturer
CIRRUS LOGIC CS8422 SRC configration are manual.

When use the 3.7V battery to drive the 16 Ohm headphones,
the S/N is up to 108 dB ,and THD is less than 0.003% .

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