We all live in a society obsessed by brand names and the latest gadget. Sometimes with reason sometimes with none.
The RPI has one major problem with audio. The clocks coming from CPU can only output one frequency clock perfect (very close), resulting in major problems with audio files sampled at 44Khz (and multiple). Too much jitter on i2s clocks. So we invented the Kali but there is a second way.
Enter the master mode for i2s. Instead of the RPI giving the clock on the line, the DAC itself sends the clocks and RPI sends the data (file to be played). Since we used 2 clocks the problem above disappears. Ours is not the first master DAC on the market, there are others… read on.
The BOSS DAC is unique, because of the way Allo has implemented the design. First they separate the power on 3 channels and filter it: one for the digital side, the second for analog and third for the clocks themselves. Then they take the filtered power and use a second filter (LDOs) to further quiet the noise. Note that some of the best LDOs on the market (LT3042 from Linear) is used. In addition, Japanese oscillators from NDK for a very low jitter clock are used – almost as good as famous Crystek.
Finally, on the analog stage there is a film capacitor (not ceramic) for a quiet DC to feed the TI IC (ceramic exhibit some piezo distortion, not what you want in analog stage). Not happy with this, Allo has added a supercapacitor for an extra kick when analog stage is asking (like deep bass).
What they have achieved, in our opinion, is the best analog implementation of the PCM5122 on the market, while at same time correcting the clock problem from RPI.
Yes we live in a society obsessed with the latest gadgets. The BOSS however, is a very solid implementation of the PCM IC that will give you the greatest bang for your buck. It will sound great no matter what you throw at it – this was Allo’s goal and promise to you.
- New with 1.2: Latest generation ULTRA low phase noise NDK oscillators (SDA series)
- New dedicated Type C USB power input, 5V 3A independent source (see manual)
- New optimized component layout
- New film capacitors on analog stage
- BOSS 1.2 is a Master DAC compatible only with RPI 2 and 3
- Compatible with OSMC / Max2Play / RuneAudio / Volumio / Moode / PiCorePlayer / PiMusicBox / OpenELEC and others + Roon Ready
- Dedicated 384 kHz/32bit high-quality DAC PCM5122 for best sound quality
- Audio output connectors: 2 x RCA (Left & Right ) & Allo Volt Amp header
- HAT size
- Sampling Frequency ranges from 8 kHz to 384 kHz
- Ultra-low-noise voltage regulators & LPF for optimal audio performance
- Integrated EEPROM for automatic configuration (with write-protection)
- Automatically switching frequencies according to the input I2S signalsa
- Compatibility: RPI 2 and 3 only. Isolator board (at 192Khz). Relay attenuator.
- PSU: BOSS v1.2 can be powered independently after removing the jumper (see manual)
- Not Working With: Sparky, Kali
- Our HighPi case is a great fit with the Raspberry Pi and the Boss add-on board. Designed and made in Canada, it’s made specifically for add-on boards with audio connectors such as this. Now available in black, red, or clear!
- Allo now has two case options available for the Pi+Boss, an acrylic model in black or clear, and an aluminum one in black.
- The Boss Player v1.2 bundles the Boss DAC I2S v1.2 with a RPi 3B, a 16GB MicroSD card with Volumio, an acrylic case, and an Audio Power Supply for a ready-to-go solution.
Support & Downloads
- Download Product Info Sheet
- Boss 1.2 DAC Tech Manual
- Measured Jitter
- Boss Audio Precision Analysis Report
- Technical Details for Boss DAC
- BOSS 1.2 Power Feeding Instructions
- BOSS Driver on Github
- Configuring Allo Audio Cards for Raspberry Pi
- Images, Drivers & Resources
Can the Boss DAC be used in multi-node/multi-room applications? Yes, it can, with certain Raspberry Pi operating systems. Allo has confirmed that Max2Play and Volumio both support this. For further information, see;