Aikido Line-Stage Amplifiers

Aikido Line-Stage Amplifiers
The Aikido amplifier delivers the sonic goods. It offers low distortion, low output impedance, a great PSRR figure, and feedback-free amplification. The secret to its superb performance—despite not using global feedback—lies in its internal symmetry, which balances imperfections with imperfections. As a result, the Aikido circuit works at least a magnitude better than the equivalent grounded-cathode amplifier.

Aikido Noval Stereo
This is a major new revision of the old Aikido stereo noval PCB, Rev. E. The PCB color is now red, but the real difference is found in two major changes: each channel's B+ RC filter is made up of pure polypropylene (no electrolytic) capacitance and each channel requires its own separate heater power supply.
Aikido All-in-One Tube Rectifier
The Aikido All-in-One 9-pin stereo PCB contains two Aikido gain stages and both the high-voltage and heater power supplies. This FR-4 PCB is extra thick, 0.094 inches, double-sided, with plated-through heavy 2oz copper traces. In addition, the PCB is lovingly and expensively made in the USA. The boards are 8 by 6 inches, with five mounting holes, which helps to prevent excessive PCB bending while inserting and pulling tubes from their sockets.
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.
Aikido Cascode PCB and User Guide
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 LV & User Guide
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.
Aikido 9-pin Dual-Mono PCBs       .
Aikido Line Stage Amplifier Kit (9-Pin & dual-mono)
Aikido Octal Dual-Mono PCB
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 Octal Stereo PCB
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.