KHADAS Tone2 User manual

Quicksta Guide
Tone2 Maker Kit
Hi-Fi USB DAC Audio Board

* The ‘Khadas BT Magic’ Bluetooth audio receiver module needs to be purchased separately.
Setup
3 5421
3
5
4
2
1Computer / Smaphone / SBC (data-in and power-in)
‘Khadas BT Magic’ Bluetooth audio receiver module /
USB-C 5V linear power supply (power-in)
CD player (S/PDIF coax-in)
Pre-amp (analog out)-> Amp -> Hi-Fi speaker
Pre-amp (analog out)-> Amp -> Hi-Fi speaker

Inteaces
Power LED
RGB LED
Shield Cover
(Analog Circuit Area)
Balanced RCA
(Right Line Out)
Balanced RCA
(Left Line Out)
Balanced RCA
(Coaxial-input)
USB-C
(I2S, DC 5V)
USB-C
(USB 2.0, DC 5V)
30-Pin 0.5mm FPC 40-Pin 2.54mm Header
(USB 2.0, GPIO I2S, UART, DC 5V)
Khadas Audio
Tone2 V12
2207 2230
20
40
1
21
14-Pin 0.5mm FPC
CPLD
(Intel 5M80ZM68)
XMOS
(XU208)
Encoder & Button

Inteaces
14-Pin 0.5mm FPC
(USB 2.0, DC 3.3V)
4-Pin 1.2mm VIN Input
(DC 4.8~14V)

Document Download Instruction
Schematics: dl.khadas.com/products/tone2/schematic/
Specication: dl.khadas.com/products/tone2/specs/
2D DXF: dl.khadas.com/products/tone2/dxf/
3D CAD: dl.khadas.com/products/tone2/cad/
Encoder Specications: dl.khadas.com/products/tone2/specs/
Encoder & Enclosure 3D CAD: dl.khadas.com/products/tone2/cad/
Website Introduction
For the function, usage and Pin denition of each extended inteace and more
technical information, you can visit docs.khadas.com/tone2.
If you encounter technical issues during development, seek help at
forum.khadas.com.
To purchase additional accessories, please visit www.khadas.com/shop.
Maker Guide
1
2

Driver Installation
1
2
Install the Khadas ASIO USB driver
Download the latest driver from dl.khadas.com/products/tone2/driver
Resta your Windows PC
The Khadas ASIO USB driver will activate after your PC restas.
1Step 1 2Step 2
* Windows’ default USB audio driver has high latency, low sampling rates, and does not
suppo ASIO. For a better user experience, please install the Khadas ASIO USB driver.

1
2
Open the Khadas DFU Upgrade Tool
Download the latest tool from dl.khadas.com/products/tone2/dfu_tool
Download the latest Tone2 rmware
Download the latest rmware from dl.khadas.com/products/tone2/rmware
3Flash new rmware to Tone2
Connect your Tone2 via a USB-C cable to your PC, and use the DFU tool to
burn the new rmware.
4Power o and resta your Tone2
After the rmware update is completed, Tone2 needs to be powered o and
restaed to activate the new rmware.
Firmware Upgrade
1Step 1
3Step 3
2Step 2
* For more details, visit docs.khadas.com/tone2

1
2
* With the external Bluetooth Module plugged-in and Tone2 powered o (USB cable with 5V
power still plugged-in), long-press the volume knob for 5s to clear the Bluetooth pairing record.
Push
2 2
Volume Knob
Rotate
*
********
*
**
**
Action
Mode Function
Input
General
Play/Stop
Lock/Unlock
O
********
**
Mode
switch
**
Mode
switch
**
Mode
switch
**
Mode
switch
On
Increase
Decrease
Volume
Next
Previous
Track
Filter Next
Previous
Next
Previous
Single Double Triple Long Clock Anti-C
***
*
Erase
BT record
1
Push Rotate

2
2
3 1
Power Priority
* The USB-C (I2S) inteace is not standard. Only specic cables (sold separately)
can be used for linear power supplies connected to the USB (I2S) po.
* Refer to docs.khadas.com/tone2 for the priority of power input to each I/O inteace.
40-Pin 2.54mm Header
(USB 2.0, GPIO I2S, UART, DC 5V)
Power supplyPriority Power LED color
USB-C
(I2S, DC 5V)
USB-C
(USB 2.0, DC 5V)
14-Pin 0.5mm FPC
(USB 2.0, DC 3.3V)
4-Pin 1.2mm VIN Input
(DC 4.8~14V)
2
3
2
2
1
2
White
Light red
Red
Red
Red

Volume
turquoise
Light Interpretation
Volume
(mute)
1-20%
Track
red
Track
21-40% 41-60%
61-80% 81-100%
* HID volume adjusting refers
to the ‘system volume’ of the playback device, e.g. PC, Smaphone, Tablet.
HID volume adjusting
（Flashes 3 times）

Linear fast Mini fastLinear slow Mini slow
Apodizing
USB S/PDIF GPIO (I2S)I2S
AUTO
Hybrid fast Brick wall
Input selection
yellow, red
Filter selection
blue, red
* In ‘S/PDIF’ input mode,
playing, pausing, skipping tracks and adjusting HID volume are not suppoed.
* GPIO (I2S) input refers
to input I2S signal via GPIO inteace, it's only suppoed in the Tone2 Maker Kit.

* The audio format is only
indicated by the RGB ring light when Tone2 is in ‘USB’ input mode.
44.1 / 48K 88.2 / 96K 176.4 / 192K 352.8 / 384K
705.6 / 768K
64 128 256 512
DSD format
white
PCM format
yellow

Locked
(Flashes 3 times)
Encoder locked
white
Power o
Power o
grey

FAQ
Why does Windows require the Khadas USB driver?
The Khadas USB driver provides ASIO suppo and removes the latency and sample rate
conversion issue experienced with the default Windows USB driver for DACs.
What is Balanced RCA?
A new balanced audio connector standard, designed by Khadas for small form-factor
desktop DACs. It is backwards compatible with standard RCA plugs and cables, more
details visit https://khadas.com/balanced-rca
Which Khadas single board computers can be connected to the Tone2 Maker Kit’s 40-pin
2.54mm header?
The VIM1S, VIM3, VIM3L and VIM4 are all suppoed, however you will need to solder a female
40-pin header to the Tone2 rst. Please refer to the instructions in docs.khadas.com/tone2
for more information.
Please note that the Khadas Warranty Seice is no longer valid once you have peormed
soldering on the Maker Kit.
Which Khadas single board computers can be connected to the 14-pin 0.5mm FPC
header on the bottom of the Tone2 Maker Kit?
The VIM3, VIM3L, VIM4 can be connected to the Tone2 Maker Kit in this way via their onboard
female M.2 connector. You will need to purchase the Khadas T2V adapter board for this
purpose. For specic information, please refer to the instructions in docs.khadas.com/tone2.
I have connected DC power to the VIN inteace, however the Tone2 Maker Kit does not
power on, please help.
Firstly, ensure that the supplied voltage is between 4.8 to 14V. Secondly, please check if there
are any discrepancies with the DC power connector’s pin layout. Please refer to the instructions
in docs.khadas.com/tone2 for the pin layouts for each I/O inteace on the Tone2 Maker Kit.
What is the electrostatic protection level of the Tone2 Maker Kit?
All inteaces have undergone static discharge testing, the protection level is 1000V for
contact and 3000V for non-contact. Do not touch the PCBA’s circuits when the board is
powered on to avoid undesirable eects; such as damage to the board.

* For the latest FAQ, visit khadas.com/tone2-faq
What is the voltage level of the Balanced RCA connection?
4.0Vrms for balanced RCA mode, and 2.0Vrms for standard RCA mode (single-ended).
How do I use my existing XLR-3 equipment with Balanced RCA?
Purchase the Khadas Balanced-RCA to XLR-3 adapter; it is a male Balanced-RCA plug
connected to a male XLR-3 plug.
How do I use ‘S/PDIF’ input?
Attach a standard RCA cable to the orange-coloured RCA jack, and set the input mode
to ‘S/PDIF’. Alternatively, set the input mode to ‘AUTO’ and stop music playback from
other sources.
How do I connect my smaphone to Tone2 via Bluetooth?
Attach a Khadas bluetooth module to the USB-C (I2S) po, and set input mode to ‘I2S’.
Can the USB-C input be used with the USB-C output of Android phone?
Yes, Tone2 can be powered by most Android smaphones via USB-C.
What are the input priorities of the ‘Auto’ input mode?
When connecting both USB-C (USB) and S/PDIF inteace in ‘Auto’ input mode, “USB”
input has the highest priority.
When music playback over USB is stopped (you do not need to remove the USB cable),
input will switch to the ‘S/PDIF’.
Refer to docs.khadas.com/tone2 for the priority of audio input to each I/O inteace.
Can I connect Tone2 to my iPhone or iPad?
Apple’s iPhone does not suppo the Tone2. You can still connect Tone2 to your iPad using
a USB-C to C cable, but the Tone2 device information will not appear on your iPad.
Does the Tone2 suppo native DSD decoding?
Yes, DSD512 native decoding can be enabled by installing the Khadas USB driver.

Can I use the Tone2 to receive a signal from the TV via coaxial and send it to the
amplier via RCA?
Yes. Set the input mode as ‘S/PDIF’ or ‘Auto’, Tone2 will output to the RCA.
How do I adjust the HID (system) volume using the volume knob?
When Tone2 is not at or above maximum volume, turning the volume knob clockwise will
increase the device’s hardware volume. Once Tone2 is at maximum volume, continuing to
turn the knob clockwise will cause the RGB indicator to ash turquoise 3 times.
Continuing to turn the knob clockwise after this point will instead increase the HID
(system) volume of your PC.
Why can’t I adjust the HID volume whilst playing DSD formatted audio?
Tone2 does not suppo HID volume adjustment whilst playing DSD formatted audio.
Can I supply power to the USB (I2S) inteace using my computer, PC or laptop?
No. Please instead connect a linear power supply or batte bank to the USB (I2S) inteace.
* For more technical assistance, visit forum.khadas.com/c/khadas-tone

Troubleshooting Guide
The Volume Knob is unresponsive and ashing full-white when I turn it.
It has been locked, triple-press it to unlock.
My Android phone can’t detect Tone2, the power LED remains o, and USB-C is
plugged-in correctly.
Go to ‘Settings’ and enable the ‘USB-OTG’ feature, most phones have this o by default.
My Tone2 is connected to my PC and I’m playing a song but there’s no sound!
Check your computer’s sound-output device, switch from ‘Speakers’ to the ‘Tone2’.
Secondly, check that your Tone2’s input mode is set to ‘USB’ or ‘Auto’.
Help! I’ve connected my PC to the Tone2 and the lights are on, but my computer
cannot detect it!
Ensure that you’ve plugged your USB-C cable into the USB-C po labelled ‘USB’.
I cannot hear any sound from Tone2 when playing music through the S/PDIF input.
Check to ensure that your music is not DSD formatted. The ‘S/PDIF’ input does not
suppo playback of DSD music.
HID volume control does not work when playing non-DSD formatted audio and the
input source is set to USB input.
Please check if there is more than one audio player running simultaneously on your
playback device. In such cases, the HID volume control command will only be sent to one
of the audio players. Close additional audio players, only open one audio player when
using your Tone2.

Specications
Balanced RCA Line-Out Peormance
THD+N：0.000126% (-118dB)
DNR：121dB
Crosstalk, 200KΩ：> 120dB
Noise level：3.5uVrms󶀅
Output, 200KΩ：4.0Vrms
Single End RCA Line-out Peormance
THD+N：0.000158%(-116dB)
DNR：118dB
Crosstalk, 200kΩ：>118dB
Noise Level：2.3uVrms
Output, 100KΩ：2.0Vrms

What’s In The Box
Tone2 Maker Kit * 1pcs
Instruction Manual * 1pcs
Warranty Card * 1pcs

www.khadas.com
生产商：哈哒科技（深圳）有限公司
电话：[phone] 邮箱: suppo@khadas.com
地址：深圳市宝安区西乡街道海城路5号前城商业中心2709
Manufacturer: Khadas Technology Co., Ltd.
Tel: [phone] E-mail: suppo@khadas.com
Address: Room 2709, Floor 27, Qiancheng Center, Haicheng Road,
Xixiang Street, Bao'an District, Shenzhen