Preamplifier DAC Network player with DSP
MiniSharc Controller is an uncommon device which uses a powerful MiniSharc DSP. It was designed to fulfill two main functions :
- Drive a multi-amplification system with active filtering through DSP MiniSharc (from 4 to 8 channels)
- Drive a stereo system with MiniSharc's equalizer / IIR / FIR Filters (2 channels)
Usually, many devices are required to perform such tasks before the signal reaches the amplifiers. It means that using single-use devices will lead to this kind of installation :
- Source : PC, DAC, Network player...
- Source Selector
- DSP for Filtering / equalization
- Multi-channel volume control (which in the best case is set after equalization and filtering)
Using single-use devices means more and more signal conversions, external connections and usually ends with a massive and intricate system. The MiniSharc Controller avoids this issue by performing all the tasks with no conversions : all internal signals are I2S.
MiniSharc can handle any 24bit/48kHz or 24bit/kHz signal depending on the selected plug-in. It can nevertheless be fed with sample rates from 16bit/44kHz to 24bit/192kHz.
The core of this product is a DSP MiniSharc which offers many tools for audio signal enhancement.
This model is very specific since it possesses only I2S inputs, thus significantly limiting the need for sound conversion.
Moreover, it is equiped with a processor powerful enough to apply filtering parameters directly on audio-curves in the MiniDSP plugin. It can process FIR/IIR filters using data from a FIR measurement software (such as Room EQ Wizard) as well.
MiniSharc Controller has many inputs to meet all modern audio streams :
- USB Amanero for PC connection
- SPDIF Coaxial / Toslink for CD transport, DVD, Internet box
- Bluetooth apt-X for direct, fast and stable connection with smartphones / tablets.
- RJ45 thanks to a Raspberry Pi that works as a network player (Volumio, LMS...) and DLNA receptor.
Each input is linked to the MiniSharc through I2S through a source selection board specifically designed for this system. Signal conversions are thus limited to the bare minimum.
The MiniSharc has 8 channels outputs allowing the board to adress 4 stereo DAC at the same time.
BCK, LRCK signals are duplicated by high-speed logical gates.
We choose Audiophonics DAC ESS ES9038Q2M because of its small size, its precise hardware volume control and it's conversion quality.
Just after the conversion chip, two bipolar operationnal amplifiers NJM 2114 powered in 9V are used in the amperage / voltage I/V conversion, ensuring a great quality analog output.
Another OPA NJM 2114 working as a buffer secure the precision of the analog output stage.
Minisharc controller is protected by a 100% aluminum casing.
A white OLED screen displays every parameter and can be set to display Master volume or single channel volume.
3 LEDs on the right side of the device keep the user aware of the power supply status : Standby / MiniSharc active / DAC, trigger, amplifier .
An encoder on the front pannel manages volume, mute function and display mode (simple / advanced).
Input selector and Standby button are located on the left-side of the device.
The connectivity is located on the rear pannel :
On the left side : DAC outputs (RCA) towards power amplifiers .
Then a USB Port for I2S Amanero, HDMI output, Raspberry Pi SD Card Slot.
Thanks to an extension port at its core, the device carries a Bluetooth apt-X and a S/PDIF Module with Coaxial and Toslink input.
MiniSharc DSP Software can be accessed and edited through the Mini-USB connector.
Two parallel 5V trigger output can handle the power-on function of external amplifiers .
The power supply input is found on the right side of the panel. There is also a power on / power off switch that handles the whole power supply and the raspberry Pi (the Raspberry Pi stays powered when the MiniSharc Controller is in sleep mode).
A linear power supply working on a LM1084 regulator feed every module in the device.
MiniSharc Controller has an integrated micro-controller for ESS chip hardware volume. To put in another way, the MiniSharc always works at 100% volume which means that no data is lost when the volume is set at a very low level.
This setting allows the introduction of a ponderation between each channel on the DACs as well.
Every DAC can thus be set to +/- 10dB relative to the main signal. Maximum and minimum volume are automatically modified to ensure that level difference is constant all over the circuit.
Thanks to an inverted trigger, the micro controller manages the amplifiers power status.
Two 3.5mm jack 5V trigger are used to turn on/off the amplifiers.
The LED on the front side indicates in real time the state of external devices powering sequence. (Standby, DSP-DAC, Trigger).
The device can be remote-controlled thanks to an IR receptor compatible with Audiophonics' remote.
The remote offers input selection, volume control, channel ponderation parameters and display settings.
Hardware volume can be controlled through a network with the Raspberry PI using a pré-installed Python script to synchronize ALSA (or Volumio) volume with DAC volume.
( https://github.com/audiophonics/minisharc_controller_serial_vol )
MiniSharc controller is a modular device, meaning that it is possible to change the number of channels by integrating from 1 to 4 DACs.
The Bluetooth apt-X or S/PDIF module can be removed to add a I2S (HDMI) instead.
The standard version has 3 DAC that can output 6 channels and actively drive 2x3 channels speakers.
This product is produced on demand, and hand built in France, requiring a lot of assembly hours that impact the final product price.
Exemple of a connexion for active filtering on stereo
|Sample rate supported||PCM up to 24bit 192kHz|
Internal processing 16/48 or 24/96kHz
RJ45 ( DLNA / Volumio )
Mini USB for MiniSharc settings
|Outputs||6x RCA |
Output level1.54V Vrms / 2.24Vpp @ 0dB
2x Trigger 5V
HDMI (Raspberry Pi)
|Casing materials||Brushed Aluminum|
|Dimensions||41.5 x 23 x 6.8cm|
|Package||1x MiniSharc Controller|
1x Power cord