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Copyright © 2003 John Broskie††† All Rights Reserved

Cars, Planes, and Circlotrons


A Letter from Arizona

First of all, a pat on the back for an impressive website. I had heard of the Tube Cad Journal years ago, but only recently have I ever visited your site. I followed a link from rec.audio.tubes (you get mentioned there every once in a while, but you never post there, why?) to December 2000 and at first I thought you didnít know what you were talking aboutÖa SRPP circlotron? Ö a cascaded circlotron? Öjust not possible. But after searching your site and reading every article and letter that dealt with the Circlotron amplifier, I must conclude that either you donít know what you are talking about or that you are probably the best informed and cleverest tube guru on the net. Iíve got hours and hours of more reading ahead of me, but my leaning is definitely towards the latter (the late Dr. Gizmo had already come that conclusion it seems.) I do however have one problem with your take on the Circlotron amplifier: you say that the amplifier is functionally identical with the totempole amplifier. In your own words:

Johnís Response

First of all, thanks for the pat on the back. No, I donít post to rec.audio.tubes, as I donít read rec.audio.tubes. And while we are at it, thanks for considering me a guru, although I donít think of myself as a guruówell at least not a tube guru. Why not? Well, the tube gurus Iíve met have disciples (or are ardently seeking them), something I neither have nor want. This quote from Nietzsche, which I always recollect when I read of Adolph Hitlerís National Socialists, is germane:†††

ďYou would multiply yourself by ten,

†††††††† by a hundred?

†††††††††††††††† You seek followers?

††††††††††††††††††††††††† Seek zeros.Ē

No zeros here. There are a thousand places on the net where tube circuit schematics and tube circuit theory can be found, but this journal's readers are not swayed by gee-whiz enthusiasm, obvious huckstering, magic, or passing fads. Based on the email I receive and the readerís websites I have been invited to visit, I am convinced that this journalís readers are the brightest, most capable tube practitioners in the world.

Nor will gurus restrict their terminologyís meanings to those definitions found in a dictionary; instead, the word ďdriveĒ will mean voltage or current or gain or power or whatever they want it to mean at the time. Of course, when a word can mean anything, it means nothing (something the universal pantheist never figured out).

Furthermore, like all good magicians, gurus do not reveal trade secrets. I, on the other hand, cannot help but to spill the beans. A bit messy at times, but no beans are left hidden up my sleeve; whereas gurus will not give you any formulas or explanations of their designs. And why should they? How could we ever hope to understand their art, lacking as we do their secret knowledge? Without secrets, a guru is as sought-after as an empty ATM.

Now, I will let you in on a little secret...

Sorry, but how can this be so? They are nothing alike. Itís like saying that an airplane is functionally identical with a car because they both move passengers from here to there. If you can explain this to me, Iíll give you my full endorsement. Anyway, good luck and thanks for the wealth of information on all the other topics.


Arizona USA

ďAs for the performance difference between the circlotron bridge amplifier output stage and the totem pole output stage, there is none, as long as the same tubes, the same idle current, and the same drive voltage is provided. I was distressed the first time I saw an electronic textbook treat the two circuits identically. "Wait a minute, these circuits are totally different?" I thought to myself. And they are in terms of ease of setting up bias points and living within the heater-to-cathode voltage limits, but not in electrical terms. The electrons do not know that they are in a long-named circuit: they just flow and their flow is governed by the voltage relationships and impedances in the circuit. To the electron, the both circuits are identical. Our eyes disagree. But then our eyes do not have to move the loudspeaker's diaphragm back and forth.Ē
- August 2001