hopjohn
Silver Face
I recently purchased a SX-1080 (Thanks Dan) that I intend to restore. I've done some reading in other threads in preparation, but I've not seen any where a comprehensive restoration was in mind from the start. I've found threads involving recaps and general repairs of various things and even read the entire thread where MTF patiently guided a beginner through 13 pages before ultimately having them give up. A real heartbreaking thread.
Here's what I've come to know about the SX-1080 so far. Unobtanium output devices. A thermal resistor that should be checked. Power board a bit under built. One of a kind tuner ICs that can go bad.
Here's what I know about my unit in particular: It appears to be all original with FM and AM working, though I've yet to check the tape loops, aux or phono inputs. The initial DC offset was 1.2V & 1.1V (Yes, that's VOLTS!) yet the relays would still click on (worrisome). Initially the bias measured about 26mv with ideal at 30mv according the manual and that was reset to within 0.5mv. The offset has been set to under 5mv in each channel with a minimum 20 minute warmup. The offset pot sucks or I'd get it closer to 0mv. After setting the offset and bias I listened to the tuner with speakers connected and the sound seemed normal.
Okay to the point, I'd like to know some general weaknesses, areas for audio improvement (trannys included), pitfalls to avoid or common mistakes, and any other general advice on a full restoration of this unit in particular. Maybe even some replacement parts #'s for transistors that are commonly replaced or can be improved upon. Any specific areas where poly caps can make a marked difference. Any info like this at all really.
Here's what I've come to know about the SX-1080 so far. Unobtanium output devices. A thermal resistor that should be checked. Power board a bit under built. One of a kind tuner ICs that can go bad.
Here's what I know about my unit in particular: It appears to be all original with FM and AM working, though I've yet to check the tape loops, aux or phono inputs. The initial DC offset was 1.2V & 1.1V (Yes, that's VOLTS!) yet the relays would still click on (worrisome). Initially the bias measured about 26mv with ideal at 30mv according the manual and that was reset to within 0.5mv. The offset has been set to under 5mv in each channel with a minimum 20 minute warmup. The offset pot sucks or I'd get it closer to 0mv. After setting the offset and bias I listened to the tuner with speakers connected and the sound seemed normal.
Okay to the point, I'd like to know some general weaknesses, areas for audio improvement (trannys included), pitfalls to avoid or common mistakes, and any other general advice on a full restoration of this unit in particular. Maybe even some replacement parts #'s for transistors that are commonly replaced or can be improved upon. Any specific areas where poly caps can make a marked difference. Any info like this at all really.