1. Read the user's manual and other documents of each product carefully to understand the steps and principle before you get started. Please always download the most updated user's manuals from the links in the page of the items.
2. Have to use suitable standoffs between PCBs. Mind the gaps in between to avoid any short circuit if the standoffs are too short. Poor GPIO connections can also result if the standoffs are too high. 11mm,12mm and 13mm standoffs are the most common options. Connector pins may also need to be cut shorter if there is any risk of touch. The new FemtoMck clocks are pretty tall. You may also need a GPIO Spacer if the board on top doesn't have a window opening for the clocks.
3. Make sure GPIO connector pins are installed into correct positions. Shifted installed pin positions can cause non working projects or even damage the PCB.
4. Never reverse power supply. Otherwise, PCB can be damaged permanently and can not be covered by warranty.
5. Never share AC input. Each AC input must be from independent transformer coil.
6. For analog section such as I/V stage, please use dedicated dual power supply or two signal power supplies if +/- power supply is required. One single power supply can not be used for this application.
7. Never install clocks in wrong orientation. Permanent damage can be made and can not be covered by warranty.
8. To troubleshoot a project, please do it step by step. Please don't mix up software issue with hardware. If you are not sure if the software is working correctly, to make things simple, please just run a Raspberry Pi with a MonitorPi or Pro installed into GPIO. MonitorPi can be a great help to debug a project. You can select the Audiophoincs ESS DAC as the I2S driver. Trying to configure the software player settings to get a correct format showing on the screen when you play music. Please don't install any other modules until you make sure software and RPi is outputting correctly.
9. When first time use an ESS controller or MonitorPi Pro with an ESS DAC, the default volume setting will be -40dB. You have to turn it to 0dB to get a full scale sound. I highly recommend keeping the volume setting at 0dB and use an external analog pre-amplifier for the volume control.
10. FifoPi Q7 has built-in isolator so it needs two power supplies to function. It will not work if feeding with only one power supply. No XO LED is lit means FifoPi doesn't have the 3.3V clean power supply.
11. Some product doesn't by default use the external power supply option , for example a TransportPi Digi. If you want to upgrade it with an separate external power supply, you have to remove the internal power supply jumpers first. Otherwise, a short circuit can be result. The fuse can be blown and PCB can be damaged. Also have to make sure the jumpers are installed if don't use the separate power supply. As same as a StationPi.
12. The standard pin diameter for the XO socket is 0.55mm. Please never install XOs with pins bigger than 0.65mm to FifoPiQ7/MA or TransportPi Digi. It's better to replace the SMT XO sockets if the pins get loose to avoid the poor connections degrade the clock performance.
13. Connecting the coaxial cable to a u.fl socket needs a little skill if you don't use the special tool. Poor MCLK connection can result in no sound, noise or distortion.
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