03-22-2023, 12:57 PM
Thanks for the answer. I suspected as much...
The Merus *hat* is hardware limited to 48K due to the chip's BCLK and MCLK being tied together on board. But the chip itself can handle up to 192K if properly clocked. The amp board I have exposes all the pins and can be fed up to 192K/32 using correct BCLK and MCLK supplied via the USB->I2S board (although IIRC the chip internals only use up to 24 bits).
It sounds like the solution is to keep the microcontroller but be smarter about it. For posterity, probably what I'll do is have the micro apply the settings on power up over I2C, monitor LRCLK for activity, enable the amp after I2S starts, and unmute the amp. If I feel like being especially clever, I'll make a settings menu similar to the official Merus mixer and connect over serial.
The Merus *hat* is hardware limited to 48K due to the chip's BCLK and MCLK being tied together on board. But the chip itself can handle up to 192K if properly clocked. The amp board I have exposes all the pins and can be fed up to 192K/32 using correct BCLK and MCLK supplied via the USB->I2S board (although IIRC the chip internals only use up to 24 bits).
It sounds like the solution is to keep the microcontroller but be smarter about it. For posterity, probably what I'll do is have the micro apply the settings on power up over I2C, monitor LRCLK for activity, enable the amp after I2S starts, and unmute the amp. If I feel like being especially clever, I'll make a settings menu similar to the official Merus mixer and connect over serial.
