The TD-25 has an "AUDIO IN" input on the side panel which lets you connect an external audio player. This is convenient for when you want to play the TD-25 while listening to music at the same time.
To do this, all you need is the correct cable to connect your audio device to the TD-25.
- If your audio player has an 1/8"(3.5mm) output connection (iPhone, etc), then you'll need a 1/8" "stereo" cable. This type of cable can be used to connect to your cell phone (iPhone etc.), or even for the Line output on your computer. One like this;
https://www.roland.com/us/products/rcc-5-3535/
-If your audio player has 1/4" connection for its output, you'll need a 1/4" -1/8" stereo cable. One like this;
Other cables are available as well, including RCA - 1/8" stereo;
https://www.roland.com/us/products/rcc-5-352r/
Once you have chosen the correct cable, simply connect the appropriate end to your audio device, and the opposite (1/8") end to the AUDIO IN jack on the right side panel of TD-25. Then, turn up the volume and press play on your audio player. Make sure you have headphones connected to your TD-25 and its volume is up as well. If you have the main outputs on the TD-25 connected to an external mixer or amp, make sure the mixer / amp's volume is up.