The concept

Audiophonic's RaspTouch is a simple and effective hardware solution combining both network drive and DAC with reclocker. The device offers exceptional audio quality due to high level Digital / Analog conversion based on ES9038Q2M and Allo Kali reclocker.

The RaspTouch lets you enjoy your favorite music while controlling playback from its 7 "touch screen, smartphone or even your PC. The PCB dedicated to playing audio file works with a SBC (Single Board Computer) Raspberry Pi 4 B . This circuit is the reference area and the most powerful model offered by the brand.

With its large screen and wide audio connectivity, RaspTouch combines ergonomics and smoothness of sound reproduction for increased music enjoyment.

Warning: this version does not support DSD

The DAC

For this version of RaspTouch, Audiophonics integrates the excellent ES9038Q2M converter supporting sampling rates up to 384kHz 32bit. It integrates a high precision 100MHz clock, low noise LDO regulator, an ultra-low noise regulator (9μV) for the reference voltage of the chip and an ESS Altera processor.

This DAC uses HyperStream 32bit technology with a wider dynamic range while drastically reducing jitter. With this design, ES9038Q2M displays a dynamic range of 129dB and THD + N of -120dB to offer new musical horizons.

32-bit attenuation technology enables lossless volume control and direct use without preamp. This hardware volume control is controllable from Raspberry through diponible dedicated driver in our Image Volumio or under Dietpi. 

With an integrated microprocessor, the DAC is capable of automatically detecting the format and sample rate source and adapt automatically. It thus automatically detects if the source is 16bit / 24bit remaining bitperfect. This control by CPLD chip maintains high stability while preventing decoding problems as well as audible artifacts apparation.

It is compatible with formats up to 384kHz on its 2 inputs. It embeds two bipolar operational amplifiers NJM 2114 9V fed to the converting section current / voltage I / V, which allows a large analog output quality. A final PDO NJM 2214 used buffer completes the analog output stage and ensures optimum return.

Reclocker KALI ALLO

In addition to the excellent DAC ES9038Q2M the Rasptouch Kali release includes a high performance reclocker KALI developed by ALLO. Thanks to its dual clock 44/48 MHz erasing inaccuracies related to the internal clocks of the Raspberry Pi 4 B, the Reclocker greatly increases the device's performance in terms of accuracy & clock noise.

The Rasptouch KALI EDITION and offers sound quality equivalent to the best streamers audiophile market.

The connection

The RaspDAC offers full connectivity let you enjoy your audio system and it very simply. We find the connections of Raspberry Pi 4 B with 4-port USB-A 2.0, a Micro SD port, an Ethernet port and a remote HDMI output. On the USB ports you can connect all kinds of compatible devices:

• Hard Drive or USB Key
• WiFi USB Key
• USB external DAC
• Keyboard / Mouse ...

  
  
  The DAC provides an analog output and a stereo RCA input SPDIF Coaxial. Power is supplied by a DC base 5.5 / 2.1mm connected to an integrated linear power supply allowing good stability. The maximum input voltage is 7 to 9 V DC and up to 12V maximum.
  
  The power button does not just turn off the power, but before launching system shutdown. It is also possible to switch it off from the interface of Volumio.
  
  Beware, despite the native WiFi connectivity Raspberry Pi 4 B, the latter was sacrificed to install the drive in an insulated aluminum housing disturbances. The wifi connection requires a USB on external adapter (Dongle Wifi) ..

the Software

Announcing himself as a free system, the RaspTouch comes without operating system. This choice depends on your hardware, the ambition of the project and the expected functionality.

The device is ready as far as electronics are concerned, So it remains to choose an operating system and mount it on the provided micro-SD card. Many softwares are available to meet all your expectations: piCorePlayer, Max2Play, OpenELEC, Volumio ...

Depending on the software, you can access the following features:
- Complete Support and unlimited Multiroom
- Remote Play audio files stored on a media server connected to the network (NAS)
- Remote reading from a UPnP source.
- Playback from USB source (hard disk, USB key)
- DLNA Management
- Support Qobuz
- Support Airplay




The unit comes with an appropriate micro-SD card to install the operating system.