ES100 MK2 Bluetooth Receiver (+HE100 Earphones for free!)
ES100 MK2 Bluetooth Receiver (+HE100 Earphones for free!)
ES100 MK2 Bluetooth Receiver (+HE100 Earphones for free!)
ES100 MK2 Bluetooth Receiver (+HE100 Earphones for free!)
ES100 MK2 Bluetooth Receiver (+HE100 Earphones for free!)
ES100 MK2 Bluetooth Receiver (+HE100 Earphones for free!)

ES100 MK2 Bluetooth Receiver (+HE100 Earphones for free!)

Regular price $99.99
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  • 24bit Bluetooth receiver designed to deliver studio-quality sound through your ears WIRELESS - using your existing wired headphones, earphones or even speakers.
  • Dimension 1 x 2 x 0.5 inch / Weight 20g / 14 hours of continuous playback / Dedicated app featured with 10 band EQ and Ambient mode / USB audio playback / device firmware update
  • Including 2 independent Hi-fi DACs and Amplifiers (Asahi Kasei AK4375a) – the optimal Dual DACs/AMP design for both single-ended and full-differential outputs
  • Analog volume control allows to keep the optimal audio performance even at low volume level using Programmable Gain Amplifier (PGA) which is known for the best way to control the volume/ Built-in microphone supports answering calls while using earphones without a microphone
  • Max. Output Power (No load): 1.1V (3.2V peak-to-peak) at 3.5mm unbalanced output/ 2.2V (6.4V peak-to-peak) at 2.5mm balanced output [Output Impedance: Approximately 1-ohm]

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.

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

Version 2.0.2 (Jan. 2, 2019) Download
- Changed the press time of power on button to 2 seconds
- Fixed occasional 3.5mm jack detection error

​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

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.

​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

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 We reply to customer inquires within 2 business days. For other questions including business proposals, please use the Contact page. 

Warranty Conditions

1. EarStudio warrants 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. EarStudio warrants 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.