New Aikido 12Vac

Introducing the new Aikido 12Vac PCB and part kits. The key advantage of the Aikido 12Vac is that it can be operated from a lowly wallwart power supply, yet develop a fairly high-voltage B+ for the triodes.

The 5687 Aikido PCB is back, but different. Now, all the tubes are 5687s and the PCB is an All-in-One effort that holds both the high-voltage B+ and heater power supplies, just like the octal and 9-pin Aikido All-in-One PCBs.

Aikido Line Stage Amplifier Kit (9-Pin & dual-mono). Includes tubes, resistors, PS and heater bypass capacitors, two sets of coupling capacitors (PIO and film), two printed circuit boards, ceramic tube sockets, and board stand offs.

Aikido "All in One" LSA/HPA kit. Aikido 9-Pin stereo PCB, resistors, regulated high-voltage and heater power supplies, capacitors, heatsinks, solid-state devices, ceramic tube sockets, board stand offs, tubes and coupling caps—everything that is needed to populate the PCB available as options.

New Aikido "All in One" LSA/HPA kit. Aikido octal stereo PCB, resistors, regulated high-voltage and heater power supplies, capacitors, heatsinks, solid-state devices, ceramic tube sockets, board stand offs, tubes and coupling caps--everything that is needed to populate the PCB available as options.

New octal CCDA PCB and custom kits: PCB, resistors, high-voltage PS and heater PS capacitors, heatsink, solid-state devices, a selection of coupling capacitors and tubes, ceramic tube sockets, and board stand offs—everything that is needed to populate the PCB. Comes 16-page user guide

New Rev. B 9-Pin CCDA PCB and custom kits: PCB, resistors, high-voltage capacitors. Comes 16-page user guide

The ACF-2 octal is an All-in-One design that holds both the B+ and heater power supplies and two Aikidoized cathode followers. In other words, the ACF-2 octal is a unity-gain buffer for those who do not need any extra voltage gain, but do need more current delivery than a passive line stage would allow.

The Unbalancer is a tube-based, balanced-to-unbalanced converter that accepts a balanced input signal and puts out a single-ended, unbalanced signal, much like a Broskie cathode follower, but with gain. (In fact, a Broskie cathode follower is the output stage in the Unbalancer circuit.) The input stage is a differential amplifier with a constant-current source load on the coupled cathodes. Besides performing its unbalancing conversion, the Unbalancer circuit provides voltage gain and exhibits a fine CMRR.

The ACF-2 is an All-in-One design that holds both the B+ and heater power supplies and two Aikido-ized cathode followers. In other words, the ACF-2 is a unity-gain buffer for those who do not need any extra voltage gain, but do need more current delivery than a passive line stage would allow.

The cathode-coupled amplifier needs a bit more help to make a first-rate line-stage amplifier. Adding an Aikido cathode follower to the CCA input stage makes a complete, high-quality line-stage amplifier that offers low distortion, low output impedance, wide bandwidth, no phase inversion, and a stellar PSRR figure.

A new Aikido PCB, the LV Aikido, which is meant to replace my old 24V Aikido board. The 6GM8 is an amazing little tube and I am quite surprised by just how good this little tube can sound, but the 6GM8/ECC86 tubes have become so rare and so expensive that some other tube must be used. Thus, the "LV Aikido," which stands for low-voltage Aikido, as this board could be used with either a B+ of 24Vdc with 6GM8 type tubes or 48Vdc with ECC99 or 12BH7 tubes.

The BCF receives a balanced input signal and converts it to an unbalanced output. It is a unity-gain buffer that offers a high input impedance, a low output impedance, low distortion, and great CMRR. In addition, because the BCF uses a push-pull topology, its use is not limited to line-stages, as the BCF can be used as a headphone buffer-amplifier if the headphone's impedance is high enough (say, 300-ohms).

The Aikido cathode follower PCB/kit is a modest affair, consisting of one tube per channel (two triodes per tube envelope) and a handful of capacitors and resistors. This unity-gain buffer, using a modified cathode follower, offers a high input impedance, a low output impedance, low distortion, and a great PSRR figure. In addition, the ACF does not invert the phase. The ACF use is not limited to line-stages, as the ACF can be used in creating an active crossover or even a headphone driver, if the headphone's impedance is high enough and the tube robust enough.

Custom Aikido Line Stage Amplifier Kit (Octal & dual-mono). Select only what you need: tubes, resistors, PS and heater bypass capacitors, two types of coupling capacitors (PIO and film), printed circuit boards, ceramic tube sockets, and board stand offs.

Aikido Line Stage Amplifier Kit (octal-based & stereo). Includes tubes, resistors, PS and heater bypass capacitors, two sets of coupling capacitors (PIO and film), printed circuit board, ceramic tube sockets, and board stand offs.

The Aikido Cascode amplifier is a compound circuit consisting of a cascode input stage amplifier and an Aikido cathode follower output stage buffer. The cascode circuit offers two huge features: gain, lots of gain; and low, very low input capacitance; thus, it delivers high gain and wide bandwidth. The cascode amplifier offers high gain, but a dismal PSRR and high output impedance. Fortunately, the Aikido cathode follower topology can undo the leaked power-supply noise, while presenting a low output impedance

Aikido Line Stage Amplifier Kit (9-Pin & stereo). Part kits include tubes, resistors, PS and heater bypass capacitors, coupling capacitors, printed circuit board, ceramic tube sockets, and board stand off assemblies.