27-03-2015, 05:29 PM
(25-03-2015, 10:07 PM)Old Sparky Wrote: The red and black wires are the speaker connections, the red pair should be the LH, and the black pair RH channel. These sets have a conventional stereo amp. in which one side of the o/p goes to chassis. The 108SR (and 106S) has two pairs of AD161 & 162 transistors on the back panel, whilst the older 103S & 104SR has a seperathe amplifier in a small box which connects to the head unit via a multi-core cable. A few years ago I repaired two 108SRs in which the wiring had suffered due to the ingress of water. Because of this, all the internal wiring had to be removed and replaced, which was time consuming to say the least! Fortunately I had the service manual, which includes an inter-pcb wiring diagram, and had worked on these back in the 70s. Incidentally the 103, 104, and early 106/108 models used a complex brushless motor with a 3-phase circuit. This was replaced, no doubt on grounds of cost, in later sets, by a standard DC Motor. A further point to note is that some players were dual polarity, indicated by the N/P suffix, whilst others were Negative Earth Only
Mine has 108 SN N/P written on it. There is a thick black wire plus another grey one fixed to a plug. Last time I spent a few minutes seeing if it would power up I got no joy at all. Next time I'll see if the motor is still up and running but I think some rewiring will be on the agenda.
I've been playing my other 8 track a fair bit and, once in a blue moon, the belt may flirt off.
I was surprised by how negative people are online towards 8 tracks. Most have called it the worst system ever invented due to wear of tapes, wow and flutter, tangled tape and basic audio quality. However, one guy has opened an 8 track museum in Texas and it's true some of the tape fetch a lot of money.
