ton4eff
Active Member
Hi, I bought this Marantz 1060 "in perfectly working condition" recently. Don't ask for the price I paid . What I saw inside however, was a P700 board devastated by some “criminal” and a baked transformer (you know the smell). As you can see from the pictures, there are lots of burnt spots on the board, broken traces and burned insulation paper of the transformer. All transistor were replaced with unknown "things", missing heat-sinks for driver transistors along with the plastic bases for them, missing screws etc... And all this awful solder job...
Long story short: I decided to rebuild the unit, as close to the original as it's possible, starting from the P700 board. I drew new schematic in the PCB editor (attached below in PDF format) and did a 3d model (not finished yet) for the future board. I have yet to see how to recreate these nice curved fat traces, as they are on the original P700 board. For this project I don't like modern "sterile" 45/90deg. angles. And maybe it's important for the sound too.
During the drawing I noticed, that the P700 board is the same for 1060 and 1030 models. The schematic is 99% the same as in the 2230 model. The only difference is swapping of values for some resistors - R713, R721 in 1060 and R758, R759 in 2230 (and the other channel accordingly). As you can see in the schematic attached I made a few minor corrections:
1. Added C705 and C706 - missing in my copy of the schematic for the 1060 and present on the PCB and on the schematic for 1030.
2. Corrected value for C711, C712 from 1uF to 10uF.
3. Corrected designators for C729, C730 -> C723, C724.
4. Bumped value for C703 and C704 to 220uF.
And here I have an important question: On the PCB there is no place for R759 and R760. May be they were soldered on the back side and removed by someone? Or they simply didn't installed in the factory?
And here is the unfinished yet 3d model of P700 board:
Long story short: I decided to rebuild the unit, as close to the original as it's possible, starting from the P700 board. I drew new schematic in the PCB editor (attached below in PDF format) and did a 3d model (not finished yet) for the future board. I have yet to see how to recreate these nice curved fat traces, as they are on the original P700 board. For this project I don't like modern "sterile" 45/90deg. angles. And maybe it's important for the sound too.
During the drawing I noticed, that the P700 board is the same for 1060 and 1030 models. The schematic is 99% the same as in the 2230 model. The only difference is swapping of values for some resistors - R713, R721 in 1060 and R758, R759 in 2230 (and the other channel accordingly). As you can see in the schematic attached I made a few minor corrections:
1. Added C705 and C706 - missing in my copy of the schematic for the 1060 and present on the PCB and on the schematic for 1030.
2. Corrected value for C711, C712 from 1uF to 10uF.
3. Corrected designators for C729, C730 -> C723, C724.
4. Bumped value for C703 and C704 to 220uF.
And here I have an important question: On the PCB there is no place for R759 and R760. May be they were soldered on the back side and removed by someone? Or they simply didn't installed in the factory?
And here is the unfinished yet 3d model of P700 board: