TANDY 1000 RSX (250-1454/55) Settings Faxback Doc. # 1319 Changing the Line Audio Jumpers: E8-E9 Microphone plugged into connector. E4-E5 Headphones plugged into Ear Connector. E7-E8 For speakers, recorders and other audio equipment. Your system can tell what kind of sound (audio) equipment you're going to plug into your microphone connector by checking to see which two of the three pins have the jumper placed over them. The default setting for the jumper labeled E8-E9 lets you plug a microphone into the microphone connector. The default setting for the jumper (E4-E5) lets you plug a set of headphones into the EAR connector. You can also plug speakers, recorders, and other audio output equipment into the EAR connector. If you want to plug audio equipment with line-level input into the connector, you must change the jumper setting to E7-E8.