The DAC BOSS from ALLO is a converter with DAC PCM5122 decoding signals up to 32Bit / 384kHz for Raspberry Pi and Allo Sparky . It is part of the range working with the ALLO Sparky SBC universe.
The present technologies are inspired by the ALLO KALI Reclocker fused into a compact 32-bit DAC.
Digital processing in high-end I2S format :
The clocks generated by the Raspberry Pi's CPU and not by an external clock cannot output a precise frequency of 44.1khz, which can cause problems with audio files sampled from 44.1Khz to 384Khz. The direct consequence is a much too high Jitter on the clocks.
A PDF to download showing the masterclock jitter rate of the DAC ALLO BOSS on Teledyne Lecroy's measurement bench (see download tab.).
The DAC BOSS generating its own Masterclock it recovers the fragile DATA digital signal in its entirety providing a very low noise drift. You just have to switch to I2S master mode on your dedicated software player, so the Raspberry Pi no longer sends its clock but only the data to the DAC.
The analog stage has as few passive components as possible on its path using DC film and non-ceramic filtering capacitors (less piezo distortion).
3 Very low-drift LDO regulations :
The DAC BOSS is unique in its design and implementation. ALLO separates the voltages on 3 channels by using 3 filters per shielded choke and capacitors :
- One channel for the digital stage
- A second one for the analog stereo stage
- A third one for the 2 NDK clocks 45.1584Mhz (for multiple of 44.1Khz) and 49.1520 MHz (for multiple of 48Khz)
Then the filtered power is filtered again by regulators (LDO) to further reduce the noise. The best LDO regulators on the market are used (LT3042 Linear), as well as clocks in the same range as the audiophile brand Crystek: NDK Japanese clocks. Finally, a super double button cell type capacitor under the main regulator acts as a current reservoir avoiding pumping effects during high dynamic demands of the audio message.
the DAC ALLO BOSS directly compatible with the ALLO VOLT AMP amplifier thanks to its 8 PINs provided directly on the PCB. These two devices being themselves compatible with the SBC ALLO Sparky or the Raspberry Pi 3 and Pi 2. So you can use it on a Raspberry Pi 3 or Pi 2.
In conclusion, this DAC ALLO BOSS is one of the best implementation of the DAC PCM5122 on the market, while correcting the native clock problems of the Raspberry Pi and the THD electrical pollution.
This DAC BOSS is a HAT type DAC and can therefore be directly connected to a Raspberry Pi.
It is also compatible with the ALLO Sparky SBC.
This DAC is compatible with the following distributions for Raspberry Pi (click on the logos) :
This DAC is compatible with the following distributions for ALLO Sparky (click on the logos) :
Review knock OUT AWARD
DAC Features :
- DAC PCM5122: 32Bit / 384kHz (Data sheet attached below)
- HAT Size : Raspberry Pi compatible, Allo Sparky compatible
- Signal-to-noise ratio : 112dB
- THD+N: -93dB
- Dynamic range: 112dB
- RMS output level: 2.1Vrms
- Crosstalk between channels: -110dB
- Supported sampling rates: 8kHz to 384kHz
- Linear technology voltage regulators LT3042 (very low drift)
- Integrated EEPROM for automatic configuation (with write protection)
- Automatic frequency switching based on I2S input signals
- 2 NDK Ultra Low Noise clocks for the Master Clock generation
- Frequencies 45.1584MHz and 49.1520MHz with ultra low phase noise oscillators
Dimensions / Weight / Connections :
- Gold Plated RCA Stereo Output
- 40-pin GPIO connectors
- 8 PIN connectors for the VOLT AMP amplifier
- Screws and spacers supplied (see photos)
- External battery connector (solder)
- Operating temperature: 0 to 70°C
- PCB dimensions: 67.4x65x22.2mm
- Net weight: 28g
- Complete test comparing dac allo boss to dac audiophonics es9018k2m -
- Illustration du DAC BOSS branché sur un Raspberry Pi 3 -
Schéma de branchement
pour GPIO RPI Pi2/Pi3 et ALLO VOLT