A Modern Driver PCB for the Citation V
NOTE: This is a prototype and I have not fully tested it. Also, The holes are not placed correctly.
When I bought a working, but scrappy looking, Harman Kardon Citation V, I did not dream at the time I would completely tear it apart for a rebuild. I like the design, the output transformers are excellent, so I got the urge to completely rebuild it. While the whole project is ongoing, part of it is to create new, sexier PCBs for the audio circuits and power supply. Here is (re)Vision 1 of the new driver board:
This board is laid out such that each side is a mirror image of the other. All text and designators are printed on both sides. The plan is to put the power resistors on the bottom (which means facing up when amplifier is in operation), and to put the capacitors on the top (which is then down in the amplifier). Being as heat rises, the capacitors will thus be kept cool. Also added is the 10M45 current source in the place of the LTP phase inverter tail resistor. This is also a double-sided layout, and the single part placed will be on the bottom (hot) side of the PCB.
The Altium Designer files are hosted at: HK-Citation-V-Driver-PCB
More to come:
- A power supply PCB, carrying everything but the doubler caps and screen choke;
- Tube complement modified to 6AG7, 6SN7, and 807 (overall circuit topology remains the same).
- Chassis modified for appropriate sockets, chassis and transformer tops stripped and powder coated brown (compatible with original brown transformer cores).