RAL keb02ip dac headphone amplifier

In Stock
Add to Wish List

NEW improved KEB02iPL V2 Version.

This RAL Audiophile grade DAC and balanced headphone amplifier is iPod, iPhone, & iPad compatible.

Dual operation mode enables to you to connect to various music source devices.

The brand new ESS SABRE32-2M ES9018K2M DAC allows you to enjoy a finer, more crisp sound.

Includes dual separate headphone jacks for balanced output and single end output.

Battery life varies depending on connection type and load. But for example the battery will last 5hrs. to shutdown when continuous playing with SONY XBA-40(8 ohms) earphone and iPad Mini. It requires Aprox. 2hrs.45min. to be charged fully.

EnjoyTheMusic.com Review

Dual operation mode enables you to connect to various music source devices

KEB02iP has two operation modes, iPod® compatible USB Host mode and USB-DAC device mode.

USB Host Mode

iPod Compatible mode works with iPod®, iPhone® and iPad®.

USB Host mode to communicates with Apple Devices like iPod, iPhone or iPad with USB-A to 30 pin dock connector or Lightning connector cable.

In this mode, the USB-A connector is enabled and KEB02ip works as an USB Host. The Apple Device works as a Full Speed USB Device. As music data is transferred by Apple's specified protocol, the resolution and sampling rates are limited to 16bit / 32k, 44.1k and 48kHz.

This mode is set at iPod position of Mode Select Slide Switch.

KEB02iP derives digital music streams from apple products or the iPod / iPhone / iPad. It then converts the digital signal to audiophile quality sound and drives balanced headphones with a fully balanced analog circuit.

USB Device Mode

In this mode, the mini-B connector is enabled and KEB02ip works as an USB Audio Class 2 compatible High Speed device and supports 16 or 24 bit resolution, 44.1k to 384kHz sampling rate and native DSD2.8/DSD5.6(DoP format 1.1).

This mode is set at BT or BP position of Mode Select Slide Switch. USB data transfer gets executed in Asynchronous Isochronous mode.

USB-DAC mode works as a USB Audio Class 2 compatible Device with Windows® PC or Mac® running on MAC OS X 10.6 or newer.
Note: USB Audio Class 2 driver for Windows is required Download from www.ratocsystems.com and install it to PC

KEB02iP supports High Resolution Audio up to 24bit/384kHz PCM and DSD128.

Fully Balanced Circuit and Balanced earphone output

Incoming Music data through USB is converted to I2S(PCM) or DSD music data stream clocked by accurate 22.5792MHz (512*44.1kHz) or 24.576MHz (512*48kHz) X-tal Oscillator modules and then transferred to the DAC.

KEB02iP has a High-grade Audio File Class DAC, ESS ES9018K2M. The DAC includes Jitter-Free processor, selectable digital filters and brings low distortion(-120dB), high DNR(127dB), accurately decoded analog signal and pure high quality sound.

TheDAC is consists of a fully balanced analog circuit from the DAC to the earphone driver.

The circuit includes four independent I/V converters, six independent filters and six independent amps. The output level volume of all six amplifiers are controlled digitally by only one DSP Master Volume controller in ES9018K2M to avoid gang error at low volume level(*1).

The fully balanced circuit and balanced connection of earphones bring good separation of L, R, accurate positioning of instruments and spreading of sound space.

KEB02iP has high quality 3.5mm mini-jack and 2.5mm mini-mini jacks made by Japanese company Hoshiden, these jack are suitable for faint and low current audio signal, superior to environment resistance and have strong durability for plug-in-out(*2).

(*1) DENON DA-10 Portable DAC uses analog double-ch. variable resister and had this gang error between L and R at low level (8 to 10 o'clock) and was claimed as an initial failure.

(*2) Some Portable Amp manufacturers ALO or others use IRIS Connector(4P). But the connector was originally developed to drive telescope lens motor of security camera and to support high current and DC battery DC30V/0.5A. It is not suitable for faint and low current audio signal. Also, this connector does not have shield GND.

Dual separate headphone jacks for Balanced and Single ended output

KEB02iP includes two independent headphone amps for balanced output (2.5mm-L and 2.5mm-R) and single ended output (3.5mm stereo).

Balanced headphones driven with a fully balanced amplifier brings good separation, good positioning of instruments and clear natural sounds.

The volume control of both KEB02iP and KEB02AK are controlled by digital with DSP inside ESS DAC to avoid gang errors.

Convenient functions

KEB02iP has two convenient switches. A Filter Selection switch enables the user to select Sharp roll off or Slow roll off digital filter curve.

Output level Low/High selection switch enables the user to select headphone output level. Use these switches and set your favorite sound and level.

Press and Reviews

Enjoy the Music Review by Michael Mercer - Feb. 2015

Headfi Review by FullBright 1 - Feb. 2015

Positive Feedback Review Issue 78 - March 2015


Compatible with:

- 30P Dock connector models.
iPod touch(1st – 4th generations)
iPod nano(3rd – 6th generations)
iPod Classic, 120GB Classic, 160GB Classic
iPhone3, iPhone3GS, iPhone4, iPhone4S
iPad, iPad2, iPad3

- Lightning® connector models.
iPod touch (5th generation)
iPhone5, iPhone5C, iPhone5S
iPad(4th generations), iPad mini, iPad Air

- Digital Audio streaming format.
L-PCM 16bit/32kHz, 44.1kHz, 48kHz
* Restricted by iPod Firmware or iOS Audio Output Driver.

- Includes reliable 3.7V/1200mAh Li-Polymer battery(made in Japan). It brings 4hr
operation with two hour charging time.

- 32bit Multi Thread processor and two independent X-Tal oscillator modules
(24.576MHz and 22.5792MHz) are included. The silicon and oscillators brings Low jitter
accurate Audio Master Clock to ES9018K2M DAC and brings clear sound.

Power & Volume Level

(1). Power & Volume Level
Power off : Turn Counter Clock wise to 7 O'clock position and check Click sound and
lighting off PW/LB LED.
Power on: Turn Clock wise from 7 O'clock position and check Click sound and lighting on
Volume level control: adjust Headphone output level to your favorite level.

(2). PW/LB LED.
Light on to indicate the operating state. Green light indicates Battery level is over 3.4V
and Red light indicates Low Battery state below 3.4V. In this case, charging is required.

(3). HP level Slide Switch
Select Headphone output level.
Right position shown in above brings High-Level for high impedance headphones.
Left position shown in above brings Low-Level for Low impedance headphones.

(4). Analog Filter selection Switch.
You can select Analog Filter Curve inside ES9018K2M DAC with this switch.
Right position brings Sharp Roll-Off Curve and Left position brings Slow Roll-off Curve.

(5). 3.5mm mini Jack.
Stereo analog audio output for headphones. Supports 8 Ohm to 300 Ohm impedance.

(6). 2.5mm micro jack ( L –BAL – R )
Analog Audio Balanced amp output to drive 4-wire ( 2 wire for L, 2wire for R) type

Rear panel

(1). Digital Audio Stream Input for iPod/iPhone/iPad
USB-A Connector : Compliant with USB 2.0 Full Speed(12Mbps) Spec.
*KEB02ip works as USB-Host but does not provide charging current from this connector.
It can provide USB Bus_Power to USB device up to 100mA.

(2). Digital Audio Stream Input for PC/Mac.
USB mini-B Connector : Compliant with USB 2.0 High-Speed(480Mbps) Spec. and
KEB02iP works as the USB Audio Class 2 Audio Device.
*This connector is used in USB_DAC mode. Don't connect any device when iPod
Legacy Support Compatible mode.

(3). DC+5V power input for charging.
USB micro-B Connector : Must connect DC+5V( +0.25V, -0.25V, 0.5A minimum )
Power supply unit to charge internal battery with USB-A to micro USB-B cable.

(4). Mode Select Slide Switch
Use this slide switch to change KEB02iP operation mode. This switch must be set in
Power_OFF state, Volume Knob at the front panel must be set at 7'Oclock position. And
the Volume Knob must be turned clockwise to enable operation mode being selected
by current setting of this switch for iPod Legacy Support mode or USB_DAC mode.

- iPod position(Left) : iPod Legacy Support mode.
KEB02iP works as an USB Host and iPod/ iPhone/iPad works as an USB Device. Must
be set this position before turning Power_ON KEB02iP to use this mode.

- USB position(Middle or Right) : USB_DAC mode.
KEB02iP works as an USB Audio Class 2 Device and High-Speed(480Mbps) Device.
Must be set this position before turning Power_ON KEB02iP to connect PC or Mac to
USB mini-B port. KEB02iP works with internal battery and does not require USB BUS
Power at BT position. Must select BT position to connect Apple Camera Connect Kit,
Lightning to USB Camera Adapter or SONY WALKMAN USB Connection canle.
KEB02ip works requires USB Bus_Power at BP position. In this case you can connect
to USB high-speed enabled HOST port of PC or Mac.

(5). LEDs

(5-1) USB(Green)/ iPod(Red)
Lights on Red when succeeded to detect iPod and starts brink to indicate being
communicating successfully with iPod.
(5-2) PCM(Green)/DSD(Red)
Disabled in iPod Legacy support compatible mode. Enabled only in USB_DAC mode.
(5-3) EXTP(Green)
Indicates External DC+5V Power source or USB Bus_Power(BP mode) is being
supplied and KEB02iP is working and charging internal battery with the external
power source or USB Bus_power(BP mode).
(5-4) Charge.
Indicates internal battery is being charged with the external power or USB
Bus_Power(BP mode).

Technical specifications

(1). Digital Audio stream from iPod/iPhone/Pad:
L-PCM 16bit/44.1kHz or 48kHz.
(2). Analog Audio output:
Single-end 3.5mm mini-jack x1(Stereo L,R). 1.62Vrms/68-Ohm x2
Balanced 2.5mm micro-jack x2 ( mono. L and R) 1.7Vrms/22-Ohm x2
(3). Battery Life:
5hr. Continues playing back music with 12'oclock Volume position with 8-ohm
Stereo earphone.
Charging time: 3hr for full charge.
(4). External DC Power requirement:
DC +4.75V to 6.0V regulated 0.5A minimum.
Required charging cable with USB micro-B plug.
Note) KEB02iP does not supply charging power to iPod/iPhone/iPad.
(5). Size: 69.2(W) x 102.2(L) x 23.4(H) mm. 2.72"(W) x 4.02"(L) x 0.92"(H)
Excludes surface projection.
(6). Weight: 232 gram, 8.18 oz.
(7). Regulations : VCCI, FCC Class B, RoHs.

iPod Compatible mode

USB Std. A -

30pin Dock
connector models


iPad/iPod touch (4th/3rd/2nd/1st generation)

iPod classic (80GB/160GB)

iPod nano (6th/5th/4th/3rd generation)

connector models

iPhone 5s, iPhone 5c, iPhone 5

iPad (Air/mini)

iPod touch (5th generation)

iPod nano (7th generation)

Sampling rate

L-PCM : 16bit, 48kHz / 44.1kHz / 32kHz

USB-DAC mode
USB Mini-B -
Windows® PCs or Mac with Hi-Speed USB (480 Mbps) port.
Windows PC

Windows 8.1, Windows 8, Windows 7

*Windows 64bit versions are also supported.


Mac Book®/Mac mini®/Mac Pro®/iMac®

Mac OS X 10.8.6 or later.

iPhone 5 / 5s, iPad

*iOS7 later.

*Lightning to USB Camera Adapter or Camera Connection Kit required.


NW-ZX1 NW-F880 Series.

*SONY Hi-Res music conversion adapter [WMC-NWH10] required

Sampling rate

DSD 2.8224MHz / 5.6448DATE data with Markers for DoP and standerd-compliant.

Linner PCM 24bit / 16bit, 384kHz / 192kHz / 176.4kHz / 96kHz / 88.2kHz / 48kHz /44.1kHz

Supported Analog Audio Output

Two Headphones output ( single-end 3.5mm phone jack x1 / balanced 2.5mm monoral phone jack x2 [L, R] ).

Blanced output: - 2.5mm micro phone jack for L-ch, and R-ch. (*1.7Vrms / 131mW(22-Ohm)non-clipping maximum per ch.)

Single-ended output: - 3.5mm mini phone jack for L and R ch Stereo. (*1.62Vrms / 38mw(68-Ohm) non-qlipping maximum per ch.)