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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

Most digital audio gear wants to run on its own clock. Connect two such devices and neither will follow the other, so no audio passes between them. It sounds like a problem with a cheap, easily accessible solution. Now it is.

MicroSRC sits in the middle and lets each device keep its own clock. It takes audio in at the source's sample rate and hands it to the sink at the sink's rate, converting continuously at full 24-bit quality. The two rates can be anything from 44.1 to 192 kHz in any combination.

The source can connect over I2S or S/PDIF. S/PDIF works with optical or coaxial connections through a small receiver circuit. The sink connects over I2S.

There is nothing to set up. Flash the firmware, wire up both devices and switch on. The onboard light blinks once a second while MicroSRC runs. A lock light for each side comes on as that device locks. Audio starts a moment later. If either side changes sample rate, MicroSRC notices and adapts by itself.

Highlights

  • Measured distortion and noise of −140.6 dBFS, far below anything audible
  • 142.8 dB of dynamic range, with no stray tones above −158 dBFS
  • Converts between any two rates from 44.1 to 192 kHz
  • Both devices keep their own clocks. MicroSRC never fights them for control
  • Accepts S/PDIF as well as I2S, from optical or coaxial sources
  • Nothing to configure: flash it, wire it, power it and 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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