tabpat
Member
I am working on my Sansui QRX-7001. One of the issues that its had for longer than I've owned it (around 20 years) is the CD-4 demodulator has never worked. The phono stage is OK, but it's never properly demodulated CD-4 albums. I can't remember if the light comes on or not, but it's been a dud. Anyway, I opened it up and quickly discovered that someone has been all through this thing. The capacitors are not original and they are of no-name quality. The soldering was horrific. But, there is an addition on the back of a transistor ( that coincides with where TR603 is marked on the other side) with a capacitor and three resistors - one of which has what looks to be a diode strapped across it. On the component side, there is a transistor that has two legs going through and the third leg is soldered onto a resistor (R610). There is no reference to this transistor being there in the schematic. I can't imagine it coming from the factory like this...but I also can't imagine the numb-nuts that did the capacitor replacement being smart enough to attempt a new circuit design. Anyone got a photo of theirs or any ideas???