How to connect your phone via Bluetooth and switch to FM radio? (Note: K66-1 version supports Bluetooth only.) Plug in headphones or a speaker with a 3.5mm jack. Press and hold the Bluetooth power button for 3 seconds to activate Bluetooth mode. Press the FM button to toggle between Bluetooth audio and FM radio. A solid blue LED indicates an active Bluetooth connection; a flashing blue LED indicates FM radio mode. When prompted, enable Bluetooth on your phone, search for and pair with device name “HC01”. Once paired, the blue LED remains solid. Play audio from your phone through the connected headphones or speaker. Press “+” or “−” briefly to skip tracks; press and hold to adjust volume. You may also adjust volume directly from your phone.In FM radio mode, press the ▶ button to start automatic station search and save stations. After saving, press “+” or “−” briefly to switch between saved stations; press and hold to adjust volume. Tape playback is not available when using Bluetooth or FM radio modes.How to connect a Bluetooth receiver? Ensure the Bluetooth receiver is powered on. Press and hold the Bluetooth power button for 3 seconds to enable Bluetooth mode. The white LED will flash rapidly while searching and pairing automatically. Once paired successfully, the white LED stays solid. Insert a tape and press “PLAY” to begin playback. During Bluetooth pairing, do not plug anything into the headphone jack, as this prevents automatic pairing. Press and hold the Bluetooth power button for 3 seconds to turn off Bluetooth. If no Bluetooth device connects within a set time, the white LED will flash and Bluetooth will auto-disable.