Amps and Effects

This page (and its sub-pages) are for reference purposes only. 


When I retired after decades of electronic engineering (mainly, but not exclusively, digital), I had a notion that it might be fun to spend some time with vacuum tube circuits. I started studying every schematic, and every piece of historic literature I could find. After 6 years or so, I had a pretty good handle on how these venerable old glass bottles worked. Though I had assumed at the outset that, after a century or so of development, there would probably be little room for innovation, but I was mistaken. Indeed, although a vast amount of research was conducted in the first half of the twentieth century, most innovation in the audio domain was done by a handful of visionaries (most notably, Leo Fender), after which almost everyone simply copied those early designs (often with only the most perfunctory understanding), tweaking a parameter here, adding a component there, but at the end of the day, producing designs that were easily recognizable as incremental modifications of those original designs.

This was an approach that held no attraction for me. 

When one considers the cost of top-quality components (particularly transformers), and the labor-intensive nature of building hand-wired circuits, there's very little profit potential, so if you eliminate the joy of innovation, what's left? I could probably make the same money flipping burgers!

As the designs in the sub-pages illustrate, the amps I've designed and built are quite different from anything anyone else has done before, or is doing as of this moment.

All of my designs are completely documented, and every one has been built and thoroughly tested. If you see something you like, I encourage you to bring the schematic to your favorite amp technician and have him or her build it for you.

I will certainly continue to design and build musical instrument amplifiers, and my designs will continue to evolve (wouldn't bother otherwise), so what I'm building now is undoubtedly more sophisticated than anything you see here, but what's here is still leaps and bounds beyond anything you'll find elsewhere.

When I finish one amp,. I use it, and if someone I like and respect appreciates it, I may sell it to them, or I might give it to them, and then I'll build another, but I will not cast pearls before swine, regardless of how much money the swine may offer. 

So no, Mr. Donald Trump has never had, and will never have enough money to buy an amp from me

Indeed, this goes to the basis of my reluctance to engage in any commercial venture: I will not associate with those of low nature, and will not abide my work going to the undeserving. Money can't buy everything, and my integrity is not for sale. 

“There is nothing new to be discovered in physics now, All that remains is more and more precise measurement.”

— Sir William Thomson (Lord Kelvin),  addressing the British Association for the Advancement of Science in 1900. 

Lord Kelvin was one of the greatest scientific minds in history, and it is emphatically not my intent to denigrate him for this one unfortunate faux pas. It is, however, difficult not to observe the parallels with the arrogant pomposity of a far less endowed individual whose website features the following bit of high-handed hauteur:

Q: Are there any new tube amp circuits? One amp builder claims they do not copy or clone anything. Seems hard to imagine.

A: The basic circuits for pure tube preamps and power amps have not changed in many decades. If you look at modern guitar amp schematics, you will see odd values sometimes, but the circuits will resemble those of older amps. It is only in the area of hybrid technology tube circuits where you find new ideas, such as with Z-B-X and ZBX-2, or with David Berning’s and Lars Lundahl’s resonant transformer output circuits (from the 2000s and the 1960s respectively).

Everyone building amps – or any other product – thinks they are doing something new and incredible. For the individual, the mere fact they could assemble it and have if work IS new and incredible! In the bigger picture, we see most people re-inventing the wheel… 

Well, there you have a definitive pronouncement from another inter-know-it-all ….

Okay, if what he means is: Is anyone inventing any new laws of physics; blowing their own glass, creating new varieties of vacuum tubes, revising Ohm’s Law, Thevenin’s Theorem, or perhaps employing some alien technology purloined from Area-51, then yes, I must humbly concede his point. 

Short of that however, he is simply full of shit.

This is like saying that there are no original paintings because everyone uses paint and canvas, or no original music because they all use the same notes. In my experience, the most ubiquitous conceit of all is the smug propensity to project one’s own limitations onto others and, indeed, elevate them to the status of universal, cosmic constraints.

Verbiage is meretricious so I’ll let one picture punctuate my refutation:

No claim is made that any individual component in the above architecture represents fundamentally unique basic technology; I did not invent a new kind of vacuum tube or discover a new addition to the periodic table of elements. My circuits are configured in accordance with Ohm’s Law, Thevenin’s Theorem, and the same laws of electrodynamics employed by every other Electronic Engineer for the past several centuries.


On the other hand, over the past fifty years or so, I have examined schematics for virtually every commercial tube-powered musical instrument amplifier ever built, along with technical manuals, datasheets, and scholarly papers on tube technology from throughout the 20th century, and can state with confidence that the architecture upon which every one of my amps are built is demonstrably and defensibly unique. If anyone can identify another commercially produced musical instrument amplifier that has ever used a remotely similar basic configuration to that depicted above, I will humbly stand corrected, and will withdraw my patent application.

Of course, anyone can be different for the sake of being different, but devising something that is unique and toneful … well, that’s the trick, isn’t it?

I believe the Cascodyne Architecture achieves that objective, and that’s why I use it as the basis of all my custom-built amplifiers.

In the past, I typically published my designs with complete details, right down the calculations, load lines, and build notes for every component, but I’ve been advised by legal counsel to curtail this practice. Nevertheless,  in the interest of future maintenance, I include complete schematics and board layouts, with sufficient detail to allow any competent amp technician to easily maintain or even modify my creations, with every sale. As should be obvious from the above diagram, this design is extremely simple, and indeed, this very simplicity is a major contributor to the purity of the resultant tone.

I discuss the major components in more general terms, and analyze the impetus behind this architecture here:

The Cascodyne Architecture

As to the tone, always a subjective assessment, I invite the interested to peruse some audio and video examples:

Hear here!