John Broskie's Guide to Tube Circuit Analysis & Design

18 March 2006


Printed circuit boards for the Aikido amplifier
The rumored Aikido printed circuit boards do exist, and they are beautiful. They look fabulous and feel solid in the hand. They are extra thick, 0.093" (inserting and pulling tubes from their sockets won’t bend or break this board), double-sided, with plated 2oz copper traces, clean silkscreen and solder mask. (The comment was made repeatedly that they look “military grade,” as if their intended use was inside a spy satellite, not a line stage.)

Here is how one buyer responded:

Thanks, John.

My Aikido boards arrived today, as promised, in good condition, five days after placing the order.

Knowing you through your writings I expected good things. Knowing the high end audio community where cables sell for thousands, capacitors sell for $50, ring clamps sell for $600 and stainless steel record weights sell for $100, I didn’t expect much for $39.

I am tickled to death by the incredible quality of the boards and the thorough documentation enclosed with them. Now I know why there haven’t been any new posts on your webzine since December 10th. You’ve been a busy boy!

I can’t wait to get soldering. But now I’m afraid my parts quality won’t live up to the boards!


One problem, though, these boards are so pretty, I can’t bear to enclose them in a heartless metal enclosure. I have to figure out how to safely let them see the light of day while in use, so that all can appreciate their beauty, even when Aikido is asleep.

Stuart (Happy Camper) P.

For a lot more information on the boards, follow the link to the hardware page of the GlassWare Yahoo! store And to download a PDF of the instruction sheets, click below:

     Octal Aikido PCB PDF
     Nine-Pin Aikido PCB PDF
     Three-Switch Stepped Attenuator PCB PDF

Happy soldering!

Next time
A lot more details on the Aikido PCB and its possible applications. The Aikido amplifier can serve for much more than just a line amplifier; for example, the front-end of an SE or hybrid amplifier. But even if we restrict ourselves to line amplifier use, we still have lots of room to move in. Here’s one idea in a nutshell: use the 9-pin Aikido PCB with four 6GM8s (AKA ECCC86 and 6N27P) with a truly low-voltage power supply for a tube circuit, say 24 volts. Or, if octals are more to your liking, an Aikido octal PCB with four 12SX7s and an 80-volt power supply. These two tubes were specially designed to work with low B+ voltages (electrons often bounce off of low-voltage plates, not so in a 12SX7, as it has specially treated plates).

The aikido circuit allows a great deal of experimentation. Experiment and let us know what happens.




Kit User Guide PDFs
Click image to download

BCF User Guide

Download PS-3 User Guide

Janus regulator user guide



Support the Tube CAD Journal


get an extremely powerful push-pull tube-amplifier simulator for

Only $19

TCJ Push-Pull Calculator
Version 2

Click on images to see enlargements

TCJ PPC Version 2 Improvements

       Rebuilt simulation engine
       Create reports as PDFs*
       More Graphs 2D/3D*
       Help system added
       Target idle current feature
       Redesigned array creation
       Transformer primary & secondary
              RDC inclusion
       Save user-defined transformer     
       Enhanced result display
       Added array result grid

                                       *User definable

TCJ Push-Pull Calculator has but a single purpose: to evaluate tube-based output stages by simulating eight topologies’ (five OTL and three transformer-coupled) actual performance with a specified tube, power supply and bias voltage, and load impedance. The accuracy of the simulation depends on the accuracy of the tube models used and the tube math model is the same True Curves™ model used in GlassWare's SE Amp CAD and Live Curves programs, which is far more accurate than the usual SPICE tube model.

Download or CD ROM
Windows 95/98/Me/NT/2000/XP

For more information, please visit our Web site :

To purchase, please visit our Yahoo Store:           Copyright © 1999-2006 GlassWare           All Rights Reserved