Bluetooth DAC/Headphone Amp

LDAC, aptX-HD, AAC, aptX, SBC

14 Hours Playback

USB DAC/Headphone Amp

USB Audio Class 1.0 (48KHz / 16-bit only)

Works as Preamplifier in vehicles

3.5mm output to car AUX

CAR MODE support(auto power on/off)

Proprietary DualDrive Technology

• Two AK4375a DAC/HPAMP ICs

• 3.5mm Unbalanced output

• 2.5mm Balanced output

Proprietary DCT algorithm (on/off option)

• Eliminate noises in digital sound sources

• Enhances 16bit into high resolution 24bit

Built-in Analog Volume control

Noise free even with high-sensitivity earphones

Hands-free call with built-in high sensitive microphone

Companion Android / iOS Application

• Codec selection

• 2.5mm / 3.5mm output mode selection

• Battery level status

• Analog & Digital volume control

• 10-Band Embedded GEQ control

• AK4375a DAC filter selection/ Oversampling selection

• Proprietary DCT level control

• Cross-feed level control

• Microphone gain control

• Ambient mode On/Off

SPECIFICATIONS

Output Power

• 3.5mm Unbalanced: 1.1Vp @ 16Ohm

• 2.5mm Balanced: 2.2 Vp @ 16Ohm

Output Impedance

• 0.5~1 ohm

SNR* (1KHz, 20KHz AES17)

• 3.5mm Unbalanced: 109dB (+2.8dBu)

• 2.5mm Balanced: 110dB (+8.8dBu)

Bluetooth Range

• 10 meter

THD+N* (1KHz, 20KHz AES17)

• 3.5mm Unbalanced: 0.0022%

• 2.5mm Balanced: 0.0014%

*SNR and THD+N measured in USB DAC mode

QUICK GUIDE & MANUALS

QUICK START GUIDE

MANUAL (EN)

MANUAL (JP)

MANUAL (KO)

MANUAL (FR)

WHITEPAPERS

State-of-the-art Bluetooth

DualDrive

Analog Volume

APPLICATION NOTES

DAC Filter

LDAC performance

Preamplifier

macOS Bluetooth Codec

ES100 vs. BTR3 Performance

ES100 vs. M0 performance

ES100 BT/USB performance

FIRMWARE UPDATE

Please download the latest version of firmware and refer to the DFU user's guide in the following zip file. During download, a warning message may appear due to some exe files in the zip file, but please disregard and proceed with the download.

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DFU user guide links: macOS en  jp  ko, Windows en  jp  ko

Version 2.0.2 (Jan. 2, 2019)

v2.0.2.zip  Download
- Changed the press time of power on button to 2 seconds
- Fixed occasional 3.5mm jack detection error

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Version 2.0.1 (Nov. 8, 2018)
- Bluetooth 5.0 support
  This new firmware based on Bluetooth 5.0 would provide more secure and stable operations though it is nothing to do with sound quality.

- EQ filter precision enhancement; double precision

- Fixed an occasional freezing issue when changing EQ filter presets

- 2.5mm 1x voltage mode output volume level adjustment
  3.5mm 1x, 2x current mode and the 2.5mm 1x voltage mode now provide the same output level at a give analog volume.
- Minor bug fixes

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Warning
From the firmware v2.0 or later, ES100 supports Bluetooth 5.0 specification. Firmware update with the latest version v2.0 or later is available, but please note that reverting back to v1.4.2 or before  is not possible. Once you have it updated with v2.0 or later, DO NOT revert the firmware back to v1.4.2. The device will be bricked.

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Version 1.4.2 (Sep. 17, 2018)

- EQ preamp bugfix in v1.4.1

- aptX HD stuttering bugfix in v1.4.0

- Fixed occasional multi-point pairing failure issue
- Optional 2nd device reconnection
- Added USB DAC 44.1KHz support
- Added USB DAC 24-bit support (macOS only)
- Added max. volume limit option
- Added EQ headroom option
- HFP option (for old Android devices)
- Minor bug fix on voice call volume control
- Better antenna sharing with Wi-Fi

WHERE TO BUY

North America - amazon.com

US (*)

CANADA

Europe - amazon.com

UK (*)

ITALY

GERMANY (*)

SPAIN

FRANCE

* Below EU countries can also order from Amazon UK or Amazon GERMANY: 

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Sweden, Finland, Estonia, Latvia, Lithuania, Denmark, Netherlands, Belgium, Luxembourg, Poland, Czech Republic, Slovakia, Austria, Slovenia,

Hungary, Romania, Bulgaria, Portugal, Malta, Greece, Cyprus and Ireland

Japan - amazon.com

South Korea - online shops

South Asia - online shops

TAILAND BKK Audio

VIETNAM Xuan Vu Audio, David Audio Choice

Asia - online shops

  SINGAPORE

HONG KONG

Following countries can also order from Amazon US (non-FBA):

Taiwan, Hong Kong, Thailand, Vietnam, Philippines, Singapore, Malaysia, Indonesia, New Zealand

Customer Support

Please check carefully the manual in this page and the DFU user guide in the firmware zip file first. Afterwards, for technical support, please email to  Basically we reply to customer inquires within 2 business days. For other questions including business proposals, please use Contact Us page 

Warranty Conditions

1. Radsone warrants EarStudio products for 30 days from the date of purchase against manufacturing defects. In this case, we offer an exchange with an equivalent new product for free. This warranty does not apply to damages caused by accident, abuse, misuse, or modification of the products. 

2. Radsone warrants EarStudio products for 1 year from the date of purchase against the damages caused by customers. In this case, the product will be repaired or exchanged with a refurbished product at the customer's expense.