Bert 1100
Super Member
Ok, the board is now finished and it's working ! Thank you all who contributed !
The only parts reused were the SV-3A diodes (with new soft flexible wires to avoid breakages!), the 1N60 diodes and the two orange film caps.
For the pins I used some thick copper solid core wire and flattened one end in the vice, it worked very nicely. I tried to get the old pins out but it is a pain, and they were breaking as I was untwisting them, so...
Putting the board back in, I noticed the pin numbers on my old board do not match with either the marantz schematic or the new board, strange... but I did find pictures around with the same numbering as my board. probably they changed along the way since there was at least one error on my old board : output pins are both P715, for the left and for the right channels !
Also I had noticed on my old board R743 and R744 were 33 ohm and not 10 ohm like on the schematic. I first put in the 33 ohm, but as I realized there had been changes in the boards I swapped them with 10 ohm. Who knows, my board might have come from another model ?
Anyway, the power amp is back in temporarily since I will now continue with a complete overhaul.
The bias dialed in easily, as did the voltage balance. On my test speakers it seems to sound pretty good already !
I will be starting a new thread about the complete overhaul.
The pins :
Done !
Back in temporarily, monitoring the bias...Of course first "on" was with the DBT....
The only parts reused were the SV-3A diodes (with new soft flexible wires to avoid breakages!), the 1N60 diodes and the two orange film caps.
For the pins I used some thick copper solid core wire and flattened one end in the vice, it worked very nicely. I tried to get the old pins out but it is a pain, and they were breaking as I was untwisting them, so...
Putting the board back in, I noticed the pin numbers on my old board do not match with either the marantz schematic or the new board, strange... but I did find pictures around with the same numbering as my board. probably they changed along the way since there was at least one error on my old board : output pins are both P715, for the left and for the right channels !
Also I had noticed on my old board R743 and R744 were 33 ohm and not 10 ohm like on the schematic. I first put in the 33 ohm, but as I realized there had been changes in the boards I swapped them with 10 ohm. Who knows, my board might have come from another model ?
Anyway, the power amp is back in temporarily since I will now continue with a complete overhaul.
The bias dialed in easily, as did the voltage balance. On my test speakers it seems to sound pretty good already !
I will be starting a new thread about the complete overhaul.
The pins :
Done !
Back in temporarily, monitoring the bias...Of course first "on" was with the DBT....
