Hi guys,
I bought the pretty faulty SA-7800 (looked nice but it was burnt a lot inside) couple years ago.
ONLY because of your knowledge and experience which I found in the forums I was able to repair it during last two months. (Replaced all power transistors, Q6 in the phono part, bad trimmer VR7, burnt bulb, destroyed eyelets, burnt resistors, faulty power source, new AC line, DEOXID everything etc. So THANK YOU, specially to Markthefixer and also the others who were solving similar issues as I did. Among all the problems I also faced right channel oscillation. Finally I solved it by adding 200p capacitor to the B-C of the Q24 (2SC1913). I have to add that in that time there were no power transistor connected as I wanted to reach the right DC ballance first before connecting them. Originally the C18 was 100p (oscillating) and now there is 200p (not oscillating). I am listening to the device for a week now, completely functional. HOWEVER I am wondering what was the exact reason for the oscillation and if there might be some hidden problem or decrease of the sound parameters which could appear in the future. Would you have any reccommendation or similar experience ?
I bought the pretty faulty SA-7800 (looked nice but it was burnt a lot inside) couple years ago.
ONLY because of your knowledge and experience which I found in the forums I was able to repair it during last two months. (Replaced all power transistors, Q6 in the phono part, bad trimmer VR7, burnt bulb, destroyed eyelets, burnt resistors, faulty power source, new AC line, DEOXID everything etc. So THANK YOU, specially to Markthefixer and also the others who were solving similar issues as I did. Among all the problems I also faced right channel oscillation. Finally I solved it by adding 200p capacitor to the B-C of the Q24 (2SC1913). I have to add that in that time there were no power transistor connected as I wanted to reach the right DC ballance first before connecting them. Originally the C18 was 100p (oscillating) and now there is 200p (not oscillating). I am listening to the device for a week now, completely functional. HOWEVER I am wondering what was the exact reason for the oscillation and if there might be some hidden problem or decrease of the sound parameters which could appear in the future. Would you have any reccommendation or similar experience ?