ton4eff
Active Member
Ok, I'm in the "big" Marantz team already. Congratulations to me 
The receiver came in pristine condition, with a few scratches here and there mainly on the top cover. Faceplate is in excellent condition (considering it's black and even the smallest issues a more easily to notice, comparing to silver faceplate). A little scratch on the volume knob only. No scratching sounding knobs or switches. Inside it is untouched, there was a lots of dust (easily removed), no smoking smell, very important to me!.All lights working and original. First thing - measured and adjusted bias and offset. They were slightly off, most probably because of the power supply voltage standard change, 220V in the late 70's, 230V - present days. The only issue was with the power switch - flickering lights and sizzling sound when the receiver was switched on for a few seconds, until the power supply soft start delay relay clicks. Then it was a sound nirvana to me. 
. So, removed and opened the power switch, cleaned and swapped good contacts with bad ones. Now it works perfectly well, hopefully for a longer time. Next time the switch will be replaced. Also replaced all lights with white LED's (couldn't stand the enormous heat from the original bulb lamps). Now the light is slightly brighter and bluer than the original bulbs and there is NO HEAT. That is the color I like the most. I don't know why everybody wants blue LED's. The resulting color from the blue LED's looks very weird and ugly to me on the old Marantz. Now I can just seat and stare at the receiver with a drink all night long. Also replaced the stereo bulb with two red LED's, pointed 90deg. from each other (avoiding spotty stereo light). And of curse the pointer red LED light with appropriate resistor, avoiding excessive brightness. The output power is 43V on 8ohm just before clipping (as you can see on the scope picture) That's 230W rms power!?. And what would be a Marantz thread in this beautiful forum without some pictures 
:
The receiver came in pristine condition, with a few scratches here and there mainly on the top cover. Faceplate is in excellent condition (considering it's black and even the smallest issues a more easily to notice, comparing to silver faceplate). A little scratch on the volume knob only. No scratching sounding knobs or switches. Inside it is untouched, there was a lots of dust (easily removed), no smoking smell, very important to me!.All lights working and original. First thing - measured and adjusted bias and offset. They were slightly off, most probably because of the power supply voltage standard change, 220V in the late 70's, 230V - present days. The only issue was with the power switch - flickering lights and sizzling sound when the receiver was switched on for a few seconds, until the power supply soft start delay relay clicks. Then it was a sound nirvana to me. . So, removed and opened the power switch, cleaned and swapped good contacts with bad ones. Now it works perfectly well, hopefully for a longer time. Next time the switch will be replaced. Also replaced all lights with white LED's (couldn't stand the enormous heat from the original bulb lamps). Now the light is slightly brighter and bluer than the original bulbs and there is NO HEAT. That is the color I like the most. I don't know why everybody wants blue LED's. The resulting color from the blue LED's looks very weird and ugly to me on the old Marantz. Now I can just seat and stare at the receiver with a drink all night long. Also replaced the stereo bulb with two red LED's, pointed 90deg. from each other (avoiding spotty stereo light). And of curse the pointer red LED light with appropriate resistor, avoiding excessive brightness. The output power is 43V on 8ohm just before clipping (as you can see on the scope picture) That's 230W rms power!?. And what would be a Marantz thread in this beautiful forum without some pictures : 
Bulgaria looks beautiful!