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Weeb Labs
CommercialRP2350

MicroSRC

Let's make everything a clock master. All at once.

−140.6
dBFS THD+N

measured 48 → 44.1 kHz, digital loopback

Two audio devices that must each be a clock master cannot talk to each other directly. It is one of those problems that sounds like it should have a cheap answer and does not — the commercial boxes that solve it start well into three figures.

MicroSRC sits between them. The source drives the clocks on MicroSRC's input port, the sink drives the clocks on its output port, and the converter bridges the two clock domains continuously at 24-bit quality. Both of its own ports are clock slaves; it never drives an audio clock itself. The input can also be an S/PDIF stream, optical or coax, instead of I2S.

There is nothing to configure. Flash the UF2, wire both sides, power on. The onboard LED blinks at 1 Hz when it is running, two lock LEDs light as each port locks, and audio starts a moment later. Rate changes on either side are detected and handled on their own.

Highlights

  • Measured −140.6 dBFS THD+N through a fully digital loopback
  • 142.8 dB A-weighted dynamic range, no spur above −158 dBFS
  • Every input/output rate combination from 44.1 to 192 kHz
  • Both ports are clock slaves — it never fights your gear for the clock
  • S/PDIF input as an alternative to I2S, optical or coax, either polarity
  • Zero configuration: flash it, wire it, power it, walk away

Specifications

THD+N
−140.6 dBFS (997 Hz @ −1 dBFS)
Dynamic range
142.8 dB, A-weighted
Worst spur
−158 dBFS
Intermodulation
−158 dBFS (CCIF 19 + 20 kHz)
Linearity
0.000 dB error at −60 dBFS
Frequency response
±0.02 dB, 100 Hz – 20 kHz, no droop
Phase
Linear — constant group delay
Rates
44.1 / 48 / 88.2 / 96 / 176.4 / 192 kHz, auto-detected
Format
24-bit in 32-bit slots · I2S Philips · 64 BCK/frame
Latency
~8 ms at the default 5 ms target, 48 kHz
Board
Raspberry Pi Pico 2 (RP2350)

From the dev log

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