The Well-Tempered Computer

An introduction to computer audio

Portables

The most famous portable is probably the Sony Walkman.
Sony started producing them in 1980.

 

Modern portables don’t have any moving parts. The storage is an SD-card.
Often they are called MP3 players. Indeed the limited amount of storage almost forces one to use lossy compression like MP3 or AAC.

As SD-card increase in capacity, one day you might go for lossless.
Hence you need a portable able to play formats like WAV and FLAC.
You also need a high quality DAC and headphone amp.

Iriver was the first to market a high-end portable, the Astell&Kern AK100.

If there are people willing to pay seven hundred for a portable, there must be people willing to pay even more.
An indeed during CES 2014 models well in excess of thousand dollar were introduced.

 

Do you need a portable DAP

You probably already have one, your smart phone.
Unfortunately the quality of the internal DAC often is a bit pour.
Over the years they improve on it.
LG is one of the few promoting the audio capacities of their phones.
Equipped with high quality ESS DACs, they perform very well.

 

LG V10 US$ 790

A smartphone with a ESS Sabre 9018 DAC and a ESS 9602 headphone amp.

Memory: internal 64 GB, external microSD (up to 2 TB is supported)

Makes you wonder if you need a hi-end portable at all.

 

A review can be found here.

Review and Audio Measurement of LG G7 ThinQ Smartphone can be found here.

 

Early 2021 LG announced it will stop making phones.

Goodbye quad DAC

Added 2015

Acoustic Research M2 PLAYER US$1,199.00

 

Isolated digital and analogue stages

Dual high precision crystal oscillators for dierent audio formats

Flagship class Burr-Brown PCM1794A DAC

Dual Burr-Brown OPA2134 current/voltage converter

High slew rate low distortion headphone amplifier

 

64GB built-in flash memory.

 

Supports WAV, AIFF, FLAC, ALAC, APE up to 32-bit 384kHz; DSD at 1-bit 2.8MHz or 5.6MHz

 

Added 2016

Astell&Kern AK100 € 699,00

 

 

Touchscreen: 2.4inch QVGA (320 x 240) IPS

Storage: 32GB of built-in, 2 slots for 32 GB SD-card

OS: Linux

 

DAC: Wolfson WM8740

THD + Noise: 0.0009%

SNR: 110dB

 

Formats: WAV, AIFF, FLAC, ALAC, APE, MP3, AAC, WMA, OGG

Input: Toslink

Added 1/2014

Astell&Kern AK240 US$2.400

Dual-mono CS4398 for a true balanced output

SN/R: 116dB

1-ohm output impedance

50ps clock jitter

 

24/192 PCM and native DSD128 support

File formats: WAV, FLAC, WMA, MP3, OGG, APE, AAC, ALAC, AIFF, DFF and DSF.

 

Storage: 256GB of flash memory / 128GB micro SD card

800x400 resolution 3.31" Amoled touch screen

OS: Android


3.5mm combo headfi/Toslink

2.5mm 4-pole balanced headfi port

mini USB for charging or PC/Mac USB DAC use.

Added 1/2014

Aurender Flow $1,295

No, this is not a thermostat. It is a portable DAC with a headphone amplifier.

 

Input USB 3.0 ( Audio Class 2.0)
Input2 SPDIF Optical
Output 1/4 inch/6.35mm Headphone Jack
Volume Control  -110dB ~ 0dB, Velocity Sensitive Operation
mSATA Slot Optional mSATA storage up to 1TB
Output Impedance 0.06 Ohm Max
THD+N Max -114dB
IMD(SMPTE) Max -112dB
SPDIF Mode(Optic) up to 24bit/192kHz
​PCM Mode(USB) up to 32bit/384kHz​
​DSD Mode(USB) ​DSD64, DSD128 / Dop Mode
​DAC Chip ESS9018K2M​
Play Time​ 7+ Hours​
Battery​ SAMSUNG SDI 4450 mAh​
​Weight ​450g(1.0 Pounds)
Output Power THD+N 0.0002%​
                                        0.0005%
                                        0.0005%
 		 43 mW/600 ohms, 87 mW/300 ohms,
320 mW/60 ohms,
380 mW/32 ohms,
 
​THD+N  (1kHz 5.1V rms output) 0.0002%​
Dynamic Rage​ Max 122dB​
​Damping Factor >130​
Dimensions    ​ ​80 x 137 x 28 (mm)
3.1 x 5.4 x 1.1 (inches)

 

 

Added 1/2015

Calyx M $995

 

 

Display: 4.65" OLED 1280X720 (HD), Adjustable-Brightness

Core ProcessorCortex A5, 625MHzUI/UX

AudioFile Format : FLAC, WAV, DFF/DSF(64DSD and128DSD-DoP), DXD, AAC, MP3, MP4, M4A, OGG

Sampling Frequency (kHz) : 44.1, 88.2, 176.4, 352.8, 48, 96, 192 & 384

Bit Depth : 16,24 & 32

 

Output Voltage : 1.25V rms

Output Impedance : 3.3Ohm

Frequency Response : 20Hz~32kHz

THD+N : 0.0008%@1kHz at 32Ohm,

0.004%@1kHz at 16Ohm

Channel Separation : 130dB@1kHz

Dynamic Range : 114dB

 

Stand Alone USB-DAC

Compatible OS : Windows XP, Vista 7 & 8(32bit, 64bit), Mac OS 10.6+

Sample rates : Aysnchronous. 32/384. 128x DSD - DoP Memory

 

External Memory : upto 128G flash (SD-micro)

Internal Memory : 64G flash memory

 

USB: Micro

Wifi For Remote App from iOS and Android phones

 

Dimension134.60 X 69.16 x 14.50 mm (H/W/D)

Weight (160g, TBA)

Added 1/2014

Chord Mojo + Poly

 

The Mojo is a portable headphone amp.

Add the Poly and you have a complete streaming solution.

Roon, DNLA, Airplay, and Bluetooth playback.

You can also play local from a micro SD card.

Added 2016

FiiO X7 US$769.00

 

Android powered portable with ESS ES9018S DAC with swappable headphone amp.

Can be used as a USB DAC.

 

 

Audio Formats Supported
Lossless：

DSD：DSD64/128（“.iso”、“.dsf”、“.dff”）
DXD：352.8K
APE FAST/High/Normal：384kHz/24bit（MAX）
APE Extra High：192kHz/24bit（MAX）
APE Insane：48kHz/24bit（MAX）
Apple Lossless：384kHz/24bit（MAX）
AIFF：384kHz/24bit（MAX）
FLAC：384kHz/24bit（MAX）
WAV：384kHz/64bit（MAX）
WMA LOSSLESS：96kHz/24bit（MAX）

 
Lossy Compression：

MP2、MP3、AAC、ALAC、WMA、OGG...

 

 

Added 2016

Onkyo DP-X1 US$ 899.99

 

The double ESS Sabre ES9018K2M DACs and double ESS Sabre 9601K amps make balanced output possible via 2x 2.5 mm output.

 

11.2MHz DSD, up to 384kHz/24-bit PCM audio, with support for WAV, FLAC, ALAC, & AIFF.

 

dual micro-SDXC card slots

Android


Added 2016

Questyle QP1R US$ 899

  • Patented "Current Mode Amplification" in headphone AMP, all discrete components, Pure Class A circuit.

  • File Format Support：WAV, FLAC, ALAC, APE, AIFF, ADPCM, LPCM, MP3,

    WMA,WMA Lossless, OGG, AAC, DFF, DSF

  • Sample Rate：

    PCM Native: 44.1 kHz - 192 kHz（16bit/24bit）

    DSD Native: DSD64(1bit 2.8MHz)/DSD128(1bit 5.6MHz)

  • DAC：Cirrus Logic CS4398

  • Output：3.5MM headphone output, 3.5MM line out & optical output 

  • Frequency Response: 20Hz-20 kHz（±0.1dB）

  • QP1  THD+N= 0.0015%

  • QP1 R THD+N = 0.0006%

  • Output Impedance ：

    QP1: 0.19Ω 

    QP1R: 0.15Ω 

  • Memory：

    Internal: 16GB(QP1)/32GB(QP1R),

    External: supports Micro SD card 2*128GB

  • Battery：3300mAh Li-polymer， 8-10 hours

 

 

Added 2015
© Vincent Kars June 7, 2023