About this project
IMPORTANT NOTE: The 2.5mm MMCX Cable add-ons are SOLD OUT! Please do not pledge for this reward. Thank you all!
Says who? EarStudio is the world’s first and only 24bit Bluetooth receiver designed to deliver studio-quality sound through your ears WIRELESS - using your existing wired headphones, earphones or even speakers.
This thumb-sized gadget packed with technologies supports Qualcomm’s aptX HD codec, which allows you to stream 24bit hi-res music wireless. Unluckily for the iPhone users, the aptX HD codec has never been of their interest - but don’t you worry. EarStudio automatically enhances 16bit music into 24bit sound. Meaning, whatever device you are using(iPhone or Android), whatever the source is(from Spotify streaming to hi-res music files), you will be able to enjoy 24bit sound through EarStudio.
EarStudio places the most focus on the sound quality along with convenience and affordability. We use CSR 8675 Qualcomm Chip and 2x DACs of AK4375a.
- Noise free, jitter free.
To brief you through the journey of EarStudio’s operation, EarStudio reproduces the sound over Bluetooth into 88.2KHz/24Bit through Radsone’s patented DCT technology which reduces subtle digital noise and cleans the jitter from Bluetooth streaming.
- Dual DACs with analog volume control
EarStudio has optimized circuit architecture, proprietary DualDrive technology, using 2 independent Hi-Fi DACs and Amplifiers. Unlike other dual DAC audio systems, the fully differential audio signal path directly goes to the output jack, with NO switch components in the way, delivering pure signal without any loss or distortion, and with enough power. Moreover, 2 selectable operating modes support 2x current or 2x voltage, as needed by depending on the type of connected headphones. Then, we took a further step for details by adopting an analog volume control. Digital volume adjustment has the downside because it scales down PCM audio sample before the D/A conversion, resulting in harsh sound and the loss in sound detail, SNR, as well as THD. EarStudio offers analog volume control to keep the optimal audio performance even at low volume level using Programmable Gain Amplifier (PGA) which is the best way to control the volume.
- Full Balanced and single ended output
EarStudio offers two outputs: A single-ended/double current 3.5mm jack and full-balanced/double voltage 2.5mm Jack.
- The Overview
- How to use
- World's first studio-quality 24bit sound playback through Bluetooth
EarStudio supports the Qualcomm aptX HD codec, which allows you to receive 48KHz/24bit audio via Bluetooth. What’s even more special about it is that it will reproduce 24bit sound from any music streaming through over 16bit codec such as SBC, aptX or AAC. The magic behind it is Radsone's patented technology called DCT which big names in the industry(LG, Audio Technica, Astell&Kern etc) have adopted in their latest products.
As an official member of Qualcomm’s CSR eXtension program, we are one of the few R&D teams in the world with the capability of handling CSR Digital Signal Processor, especially CSR8675. EarStudio is a total assembly of our technologies, algorithms and years of dedication for high-quality Bluetooth audio streaming.
- DCT(Distinctive Clear Technology)
DCT technology solves fundamental digital audio problems by eliminating the subtle digital noise inherent in all digital sound. The longer you listen, DCT, a kind of advanced dithering will be done for a natural pattern, and it improves the masking curve associated with audio signals to virtually eliminate quantization errors. Meaning, DCT makes the sound more precise and natural, and users will be able to listen in detail. This technology is patented including USA and Japan.
DCT eliminates quantization errors, thereby generating analog-like natural patterns
Spectrogram after DCT demonstrates improved masking curve with noise suppression. Details are emphasized while maintaining the overall shape.
- DCT Blue
DCT Blue is a newly developed version of DCT specialized for Bluetooth streaming. Of course, EarStudio is the first product in the world to showcase the technology - its proprietary precise Sample Rate Adjustment scheme enables jitter-free wireless audio streaming as shown below.
EarStudio is the first Bluetooth receiver in the world equipped with 2 external Hi-Fi DACs. Our proprietary DualDrive technology doubles the given HW performance by using 2 external DACs(Asahi Kasei AK4375a), pure-balanced 2.5mm port and a customized 3.5mm port. This improves the dynamic range for headphones, especially in the bass band.
EarStudio’s 350mAh battery provides 14 hours of continuous playback. You could literally listen to music all day without charging!
Typical Bluetooth receivers usually have much shorter playback time, mostly under 10 hours. Even with its extensive battery life, EarStudio only weighs 20g, lighter than one AA battery (24g)!
EarStudio provides a regular single-ended 3.5mm jack and a pure-balanced 2.5mm jack that doubles the output power and cancels out unwanted DC offset and noise from analogue component.
Single-ended, 2x current mode fits low impedance headphones and full-differential, 2x voltage mode fits high impedance headphones. Meaning, EarStudio effortlessly drives ANY type of low/high impedance headphones you own.
The digital volume control operates on a fixed-bit field; in that case, the DAC cannot make the fractional part of the number and degrades sound quality especially in low level.
When adjusting the analog volume down to a certain level with EarStudio, the signal peak is decreased as well as noise floor; resulting in no loss in SNR as shown above. The EarStudio supports analog volume control(when controlling the volume via the app or the buttons on the device) which maintains the sound quality.
EarStudio also offers a USB port through which you can play lossless music even while charging.
Unlike most other devices, we will be supporting Device Firmware Updates for your EarStudio. This means that our further updates, optimization and bug fixes will be done at your home in a matter of seconds, not having to send the actual product to us. Keep your EarStudio software fresh for the rest of your life!
All EarStudio backers will have free access to the EarStudio iOS/Android mobile application! Through this app, the users will have detailed control over the sound and hardware.
- Basic Control
- Power On/Off
- Analog Volume Control
- DJ Mode(sync)
- Sound Control
- DCT On/Off
- Crossfeed On/Off
- 2x Oversampling
- 5 Band GEQ/PEQ
- Hardware Control
- DAC HW Control(Filter Options)
- Full-VDD/Half-VDD/Class-G Mode
Sharing with you all an incredible sound from the EarStudio demo unit through 2.5mm full balanced output, connected to FOCAL active speaker full balance input. EarStudio is connected to iPhone 7, playing through Bluetooth AAC codec. EarStudio works as a preamplifier with analog volume control capability. The FOCAL active speaker has a built-in power amplifier with +4dBu (Vpp 3.472V) professional line level input specification, which can be driven by EarStudio effortlessly. This demonstration shows that EarStudio shares a role of a preamplifier for any power amplifier with professional line level input specification.
(This demo was recorded in the Radsone office - not in a professional recording studio)
- Audio Precision Test
Audio Precision is one of the most credible devices for audio performance measurement. In this test, we have used Audio Precision 2722 equipment full balance input, then connected EarStudio through USB with PC and played a 1KHz tone. This is to measure THD+N and output voltage. Our primary goal is to provide the best sound quality, and we have gone through continuous improvements.
- Our Story
We, Radsone, are the first mover in commercializing high-quality Bluetooth audio technology. We have provided solutions for most aptX HD supported audio devices out in the current market including Audio-Technica, Astell&Kern, LG, etc.
However, some of you may recognize our name from the Radsone music player app. And yes you are right - we had developed the app a couple years back which topped the charts in 47 countries and currently has 1.4 million downloads across the globe.
- Our Partners
We currently hold 8 registered patents including DCT technology which eliminates the chronic micro noise in the digital audio. Millions of audio products with DCT technology have already been released in the market and this time, we are about to shock the world with the tiny yet mighty Bluetooth receiver packed with our own technologies.
Risks and challenges
We already have our 2nd “working” prototype which demonstrates nearly perfect performance as we had intended. Just little modifications will be made on the software and design sides before jumping into the manufacturing process.
EarStudio will be manufactured at Sambon Precision&Electronics - that has been running the Audio-Technica and JVC ODM business for more than 20 years.
We guarantee you will get what is worth more than what you paid for. Thank you for your support!Learn about accountability on Kickstarter
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