Posts from Paul have indicated for the Teensy 4.0/4.1, it is generally better that the path between the Teensy and the audio board be as short as possible (i.e. don't use ribbon cable).
As MartT says using stacking headers is one solution.
- If you are going to solder connections to the bottom of the board, it is best to do that first before adding the connectors;
- Unfortunately, the ethernet pins on the Teensy 4.1are are too close to the walls of the stacking pins;
- If you mount the Teensy audio adapter n top of the Teensy, you loose access to the Teensy reset button (Teensy 3.2 and 4.0), USB host pins (Teensy 3.6 and 4.1), the back row pins (Teensy 3.2 and 4.0), and the special analog pins (Teensy 3.2, 3.5. and 3.6);
- If you mount the Teensy audio adapter underneath the Teensy, you have the last 10 pins hanging out in space for the larger boards (Teensy 3.5, 3.6, and 4.1).
Sparkfun has a set of stacking headers just the right size for the Teensy 3.5, 3.6, and 4.1 (note, for the 5 pin header, you will typically want to clip the pins so that it doesn't stack since the normal breadboard does not have special pinouts for those pins):
Adafruit has a set of stacking headers just the right size for the Teensy 3.2 and 4.0:
Generally what I do is buy larger stacking headers, and cut them down to the 14 pin or 24 pins as needed. I use a diagonal cutter, first taking out the next pin.I use a rotary tool to smooth down the cut. Buy more than you need. I usually mess up one by cutting too close to the last pin:
Another option is to get a prototype board with dual sets of pins, and connect the first 14 rows on each side, so you can mount the Teensy and Audio Adapter in parallel:
Wouldn’t that mean soldering in the Teensy to the audio board? It’s for work and would like everything to be as easy as possible to replace because of the abuse it will likely take. I guess it’s their buck they could buy both. ��*
You could do that. Or you could solder stacking headers to the Teensy board and either stacking headers or regular male headers to the Audio board. Then you can attach the audio board to the Teensy and remove it as necessary. It would be nice if somebody offered a Teensy with stacking headers soldered in instead of either normal male headers or no headers. Likewise it would be nice if the audio board had an option to add the headers.