More interesting Raspberry Pi hi-fi from Allo


Allo Boss for Raspberry Pi

Boss is an DAC with a difference: it avoids jitter using a technique I have not seen before in a Raspberry Pi product.

Unlike the same firm’s Kali product which scrubs jitter from the Raspberry Pi I2S audio signal by re-clocking (using an FPGA, amonst other chips), Boss generates a clean local clock and injects in into Raspberry Pi’s I2S interface for it to clock audio data out on – at least, that is how I understand it.

Allo Boss DAC block diagI am not one for audio woo. All I can say is that the music that came out of a system with Kali was astoundingly clear and very ‘stereo’ sounding – however, the available software was a bit buggy at the time – hopefully that is now sorted – my system ceased to function for unexplained reasons before I could try later software versions.

Anyway, I am really looking forward to trying Boss with Raspberry Pi.

Allo Boss DAC

Allo Boss. There is a super cap on the back, and a 40pin socket for Raspberry Pi.

Boss at a glance

  • 384 kHz/32bit PCM5122 DAC
  • 2 x RCA (left right) output, and header for stacking Allo Volt power amp
  • HAT size (67.4 x 65 x 22.2mm, 28g)
  • 112dB SNR
  • -1dBFS –87dB THD+N
  • 2.1Vrms full scale out
  • 112dB dynamic range
  • 8-384kHz sampling
  • Ultra-low-noise voltage regulators and low-pass filtering
  • 66.27uVrms noise level:
  • On-board EEPROM for automatic configuration (not sure if this is filled yet)
  • Frequency auto-switched according to the input I2S
  • 45.1584MHz low phase noise low jitter NDK crystal master oscillator
  • 49.1520MHz low phase noise low jitter NDK crystal master oscillator


Source link

Leave a Reply