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First power-up

JP150PCB 1.3PCB 1.4Jan PřibyslavskýThis page does not apply to the product or PCB revision chosen in the header.

From an unpacked module to the first sound. The module ships with its firmware and the default DSP program installed, so nothing has to be programmed first.

Before you switch on

  1. Supply. Either a DC supply of 15 to 36 V on POWER IN: pin 1 GND, pin 2 positive, the polarity is protected and the inrush is limited; or a USB Power Delivery source on USB C PD, up to 100 W. Never exceed 36 V (Specifications). With both connected the module selects its supply itself.
  2. Speakers on the four screw terminals AMP0 OUT A, AMP0 OUT B, AMP1 OUT A and AMP1 OUT B, each with its + and − pin marked. The bridging options and the load the power stages accept are on Configuration and Specifications.
  3. A source, for the first sound preferably a phone over Bluetooth, which needs no cable, or a PC on USB DATA (the USB-C connector or the 3-pin header) with a USB-C data cable.
  4. Optionally the encoder on ROTARY ENCODER and a USB-C data cable to the PC for MuraLink. The pinouts are on Connectors and pinouts.

What you see at power-up

Indicator Expected If not
Power LED A low level with a short bright blip once a second: the firmware runs No light: the supply. A blip every two seconds: the module is in a power-down level; a turn or a press of the encoder wakes it
Status LED The colour of the selected input: blue Bluetooth, white Wi-Fi, magenta USB, cyan I2S, amber S/PDIF, yellow test tone Red with a dim white step every second: the safe state. Amber patterns: update mode
DSP LED Flashing (1 Hz with the default program): the DSP program runs Dark: no program in the boot memory, or the module sleeps; see Writing the boot memory
Level meter Follows the signal of the selected input Stays dark with music playing: the input is not the one that plays, or the module is in a power-down level

The whole table is explained on Indicators and LEDs. The firmware answers at once; the DSP program loads within a quarter of a second (Start-up).

The first sound

  1. Select the input. Press the encoder button to cycle through the enabled inputs, or click the input in MuraLink. The status LED shows the selection by colour; only enabled inputs are offered (Inputs and the enable mask).
  2. Bluetooth: with the status LED blue, connect from the phone's Bluetooth settings and start playback (Connect a phone). USB: with the status LED magenta, the PC sees a USB audio device named MURA LABS JP150; no driver is needed. Select it as the output device and play. Wi-Fi: needs the one-time network setup first (Wi-Fi setup).
  3. Volume. Turn the encoder, or use the master volume in MuraLink (0 to 99). The volume is saved automatically a few seconds after the last change and restored at the next power-up (Volume and encoder).

If nothing plays

  • The selected input is the one your source plays to, and it is enabled.
  • The volume is not 0 and the power stages are not muted (MuraLink: Power stage > Controls).
  • The DSP LED flashes. A dark DSP LED with the power LED alive means no DSP program is running.
  • On PCB 1.4 no red FAULT LED is lit next to a power stage; a yellow CLIP LED is only a level warning.
  • The module is in its NORMAL power level, not powered down by the automatic power-down or, on PCB 1.4, by the 12 V trigger (Power levels).
  • The status LED is not red with a white step (safe state) and shows no update pattern.

Troubleshooting continues from here, symptom by symptom.