Design your own kit. If you already own many or none of the parts needed in building your own giant-killing Aikido line-stage amplifier, the above lists of parts will help you design an Aikido kit that includes everything you need to populate the PCB. Buy just what you need and save.
All that is needed to finish the entire line stage is a chassis, power supply, volume and input selector controls, and a handful of RCA jacks and hookup wire. Although this custom Aikido kit isn't all that is needed, it is a great start.
A new single channel Aikido amplifier printed circuit board for 9-pin triodes, such as the 6AQ8, 6BQ7, 6DJ8, 6CG7, 6FQ7, 6GM8, 6H30, 12AT7, 12AU7, 12AV7, 12AX7, 12BH7, 5751, 6922, ECC99…as the input or output tube.
Why a mono version? Several reasons come to mind: some have returned to the purity of mono hi-fi (half the cost, half the headaches), on the other hand some are running five-channel systems and they require a single Aikido board for the center channel, some need a single microphone amplifier, some cannot use the larger stereo boards in their high-jacked cabinets, some are building monoblock power amplifiers and the stereo boards would be half wasted, and some might be building a stereo amplifier that will not work with the long stereo Aikido PCB, but could accept two smaller PCBs.
The board can be used with either a DC or AC (if the heater shunting capacitor is left off the board) power supply (6.3V or 12.6V) for the tubes' heaters, so that 6.3V heater tubes (like the 6FQ7 and 6DJ8) or 12.6V tubes (like the 12AU7 or 12AX7) can be used. Both tubes must share the same heater voltage. For example, 6GC7 for the input tube and a 6H30 for the output tube can be used, although they differ in heater current draw; a 12AX7 and a 6FQ7 could not be used, as they differ in heater voltage; however, a 12AX7 and a 12FQ7 could be used.
The boards are four inches by six inches, extra thick (0.93"), with 2oz copper traces, with five mounting holes. Boards are made in the USA and come with 12-page user guide, which includes schematic and recommended part values and design examples.