I have an old Marantz 240 power amplifier with a blown output transistor. For the last few years its been sitting on the shelf, just begging me to convert it into a Leach amp. The transformer is correct, and the heatsinks are set up for 4 TO-3 devices per channel. I've finally decided to get busy on it.
The Marantz PCBs were mounted on the back of the heatsink, as shown in the picture below. I could have made the original Leach v4.5 PCBs work, but since I procrastinated so long that Professor Leach has passed on, and his boards seem to be no longer available, I have made a new layout in a (larger) board size dictated by the mounting holes of the original Marantz modules. I have tried to copy the original component placements and circuit tracks, with some minor changes. One such change is to take advantage of the larger board size to add a TO-126 footprint in parallel with the TO-39 can footprint. This will allow me to experiment with different VAS transistors.
Sorry to ramble on so. I'm interested in comments on this new layout, also below. PCB layout is not my strong suit, but I've followed Leach's original layout pretty closely. I'm just wondering if any of the experts out there have any suggestions.
Also, if anyone is interested, I'll be happy to share the DesignSpark files and/or the Gerbers.
Best regards to all,
Mike
The Marantz PCBs were mounted on the back of the heatsink, as shown in the picture below. I could have made the original Leach v4.5 PCBs work, but since I procrastinated so long that Professor Leach has passed on, and his boards seem to be no longer available, I have made a new layout in a (larger) board size dictated by the mounting holes of the original Marantz modules. I have tried to copy the original component placements and circuit tracks, with some minor changes. One such change is to take advantage of the larger board size to add a TO-126 footprint in parallel with the TO-39 can footprint. This will allow me to experiment with different VAS transistors.
Sorry to ramble on so. I'm interested in comments on this new layout, also below. PCB layout is not my strong suit, but I've followed Leach's original layout pretty closely. I'm just wondering if any of the experts out there have any suggestions.
Also, if anyone is interested, I'll be happy to share the DesignSpark files and/or the Gerbers.
Best regards to all,
Mike