CAVEAT EMPTOR/DISCLAIMER: Besides the multi-million dollar annual fee I get from PF as Techno-Shaman of Coolosity many manufacturers easily corrupt my judgment with lavish gifts, like expensive foreign cars, expensive vacations in the Caribbean, and events in my honor, like the one I will describe below. With the Colombian Drug Cartel entering the turntable mat business to launder their money and bribing audio reviewers with million dollar payoffs to recommend their mats, it is essential that readers of PF be on their guard. Clearly Count Kron, by spending hundreds of thousands of dollars to celebrate my birthday was attempting to influence my judgment, and he was successful. I have made this full disclosure to protect the integrity of PF, and to admit, with pride, my imperfections and vulnerability to all forms of mortal corruption...I am very biased (because my brain is a triode ), never objective (because only machines have that ability), have a clear political agenda (I want to be President), howl like a Siberian wolf when I make love ( I am 99% mad dog/1% audiomaniac), and I am very must read all of my articles on the potty ( I only relate well to really smart people). And because I am about to become a "Golden Oldie" I have less and less tolerance for almost dead brainy white audio professors who can’t dance and express a narrow view of the audio arts. So much for audio reviewer pomposity, so let’s party.


On November 3rd I received an email from Count Riccardo Kron insisting that I come to his castle in the Czech Republic with members of the Triode Guild to celebrate my birthday, which is on November 28. At first I was embarrassed but when I showed the proposed menu and agenda of festivities to Fritz, the Audiomaniac Vampire, he said..."Dude, what you are crazy, how can you refuse....not since the Golden Days of Rome’s orgies has such a party been planned?"....and he was right, so I accepted.

Last year on my birthday my girlfriend served cold left-over Spam fritters, lumpy chocolate pudding, moldy corn dogs, and Green Cool Aid...which was okay with me because I am really not a food person. As far as I am concerned eating is time wasted that could be better spent playing with audio circuits, which is why I prefer to eat frozen TV dinners at my workbench, which I defrost with my heat gun.

On November 25 we all boarded the XH-1 ( see picture of Triode Guild XH-1 dirigible on the Triode Guild web site) with Fritz, The Audiomaniac Vampire, piloting we crossed the Atlantic. We especially enjoyed the trip because we listened to Fritz’s 78 mono collection of Django Rheinhart playing at the Hot Club of Paris in the 1930s on Terry O’Sullivan’s (Lorricraft) new version of the original Garrard 301 on a Western Electric Theater System.

We were met at the gigantic iron doors (made from output transformer laminates) of the Kron Castle with trumpets blaring, and warm greetings by the Count, who was dressed in his Lawrence of Arabia garb and his wife Eunice who had just finished her Queen Nefretitti make-over. I don’t want to bore you with details of the three days of festivities at the Kron Castle so I will just list some of them. Members of the Moral Majority, before you make a harsh judgment of these festivities.... remember I was just an invited guest and I had nothing to do with the planning. All of these activities occurred in the main hall of the Count’s ancient stone castle which measures about 150 by 150 feet, with a ceiling that is about 100 feet high.

(1) A MAGIC BIRTHDAY THRONE: On a platform near the back of the hall, which was the ideal place to sit to watch the festivities, was the most magnificent throne of the most unusual and splendid design. On close inspection, it was a classic white porcelain potty that was encrusted with the jewels of the Maharaja of Gingapoor. Count Kron was being exceedingly gracious to create this seat of honor, and let me make this plain to is a unique thrill to sit on a potty that is encrusted with diamonds, sapphires and pearls, and painted with the most divine scenes of Krishna and dancing elephants. The flusher was made from a 10,000 carat emerald rod.

(2) BARBECUE: Within the main hall was installed a gigantic barbecue pit and various exotics were roasted to delight the guests including, but limited to:

  • Brazier of Zebra tongue in a rendered wild cherry sauce with brandy
  • Leg of Ethiopian Desert Gazelle in a fig and garlic sauce
  • Indian Peacock breast stuffed with puree of mango and saffron rice
  • Mandarin Doberman in an orange sauce
  • Amazon River Anaconda in a pesto and chili sauce
  • Sumatra Rat TaTwoeey

While there were many more exotic dishes, these were the crescendos. It should not surprise you that Eunice Kron was responsible for these Epicurean dishes..... because the entire Kron family is dedicated to satisfying the exotic cravings of eccentric men of highly refined sensibilities, like you.

(3) AMAZONS MUD WRESTLING: I don’t know how the Count was able to recruit Amazon’s who, as you know, were mythical 6’5" women warriors from Scythia (near the Black Sea) who fought during the Periclean Age of Greece. Let me assure World Federation of Wrestling fans that Hulk Hogan is a weeny compared to these Amazons. The Count told me that because the audio arts are all about wrestling with the paradoxes of life this was an appropriate form of entertainment, though one Amazon had a very bloody nose.

(4). LION AND BEAR COMBAT: After Saturday’s night dinner an African lion and a Kodiak bear was brought into the center of the hall I know this will upset animal rights groupies, the eco-senstive, and Disneyites, but they fought to the death in a battle that filled the halls with the most horrible screams of agony and pain....which quite frankly (and I am embarrassed to admit this) reminded me of the pain and anguish that audiophiles often express to me. The Kodiak bear won, demonstrating once again, the power of a sincere hug.

(5). VIRGIN BURGUNDY GRAPE PEELERS WITH HOOLA-HOOPS: All during the three days of festivities, high breasted young French virgins wearing nothing but sheer tunics carried around wicker baskets of Burgundy grapes and peeled them for the guests while keeping their hoola hoops in constant motion. By the third day their skin was almost completely red from the grape juice. When was the last time a French virgin peeled grapes for you while you listened to music in your living room? Why not, you deserve it?

(6). MERLIN’S ROCKIN’ THUNDER AND LIGHTENING BAND: Again the Count blew my mind, with the guest appearance of Merlin, the magician of King Arthur’s Court, who did magic tricks that amazed us all, but the second part of his act was the most thrilling...and I still can’t figure out how he did it...but as he waved his baton this totally cool rock and roll music was heard in the hall and then when he moved the same baton with a jerk, lightening and thunder filled the sky and shaked the entire about accurate transient response and bass.

(7) THE BIRTHDAY SURPRISE: On Sunday, just when I thought it was impossible for anything to top what had happened, four Mandingo warriors wearing nothing but leopard skin tunics pushed into the center of the hall a gigantic birthday cake...maybe ten feet tall.... in the shape of a 300B...with two hundred and thirty eight for each year that I have lived in this, and all of my other previous life-times...and with a clap of Merlin’s hand, out jumped Cindy Crawford covered in nothing but whipped triode cream and walks over to me, gives me a big hug and presents me a red box. I opened the box, as I wiped the whipped cream off my body, and lo and behold the box was filled with four brand new KR 10 tubes; the new dual OCTAL medium mu triode (mega-6SN7s) that will catapult the directly heated triode revolution to the next highest plane of creamosity. As I was gawking in amazement at this new tubes, Count Kron, said, "Dr. Gizmo, it is only right that the gifted listeners of Positive Feedback should learn about my newest creation first, because it is recognized all over the world that the PF tribe is totally out there in exploring the edge of the audio arts".

I was so touched that humble little me was being given this scoop that I started to wail uncontrollably, and my tears become so profuse that a flood, or I should say, a tidal wave of tears, started to fill the hall threatening to drown everyone, and just in the nick of time Merlin clapped his hands and the flood of my tears disappeared.

Do you understand how grand this gesture was? Do you grock how much intense dream energy is in our tribe of thermionic techno-shamans for a NEW advanced form of dual triode that can be used as a voltage amplifier/driver for our beloved directly heated triode output tubes? Have you any idea of the significance of this tube and what it will mean in advancing the audio revolution on all fronts? Can you grasp the confluence of politics and art...the edge of the American music revolution is being created in the Czech Republic that was once under the control of the Communists? If not sit down by my side, get a piece of birthday cake, scoff a scoop of triode cream, and let me tell you an amazing but true story...after I ask you this important question:


It is 1493, and we are just at the beginning of the renaissance in the audio arts, which will not come into full bloom until "The Age of Discovery" gains momentum. We are in Europe coming out of the Dark Ages, and Columbus has just discovered the new world, and we are just beginning to understand that Europe is not the whole world, but only a tiny part of it. We are discovering exotic new cultures and territories we never knew existed, and we will never be the same again.

It is the same time in our audio industry. We are coming out of the Dark Ages, and entering the Age of Audio Discovery because the Internet has opened up an amazing new world to us. We are the explorers. We once thought that our world was the world, and we now know this is false; there is much more. The monolithic power authority that once dwelled in audio magazines has shattered because we are discovering that our old view, which we thought was an expansive view of the audio arts, is in fact, a very narrow minded view. This revolution is not easy. It is causing much pain, confusing to manufactures, upsetting the pundits, and it is the only and best hope for the revitalization of our community. There is no going back, so keep waxing your surf boards.



Those of you who have excavated at the Temple of Karnak in Egypt know that at the top of the main temple is written, in hieroglyphics...THE FIRST QUARTER INCH IS THE MOST IMPORTANT. We all know this ancient wisdom to be true, and it has many first few bars of any piece of music is most important...poets know the importance of the opening words of their poem (This is the forest primeval), and this logic also applies to all audio circuits....just give this piece of piety a chance.

One of the benefits of being such an old audio dog, who has published so much dribble on audio circuits over the last two decades, is that it is easy to discover that my thoughts on audio circuits haven’t change much over the decades. This may be because of severe brain damage I suffered when I was thirteen in a bicycle accident, or I may have stumbled upon some good ideas that work....I am not sure. You be the judge.

There are thousands of copies of UNDERSTANDING TUBE ELECTRONICS (published in 1982 ) out there in Audioland and you will notice that over and over again the expression LESS IS MORE, but there is one notion that is also repeated over and over again, and it had direct bearing on the Futterman circuit and my pioneering development of hybrid tube/mosfet amplifiers, i.e.....the importance of the first tube in determining ultimate audio quality of a tube circuit. Julius appreciated how important the first quarter inch was, because he planted this notion in our head....the first tube is critically important.

When I started to consider this I realized that this was like Einstein’s theorem of reality; a general theorem of the audio arts: If you screw things up in the first stage you can never get it can not be repaired. Just think about this for a moment: whatever is corrupted at the input of your audio chain will be amplified through the audio gets worse from that point...each stage will also add its own corruption. This especially applies to recording studios where microphones are the first quarter inch, and why there is such passionate consideration of different brands and types of microphones....with tube microphones still representing the concresence of the art.

We have been so gleeful over the renaissance of high quality output tubes, that we have forgotten how important the first tube is, but the thermionic tides shift, and it is time to return to aesethetic consideration of the input stage. Obviously on the Triode Guild web site this theme is repeated ad nauseum, with me suggesting you should hunt for the best NOS, pre-1960s input tubes for your single-ended triode amplifiers. I have gladly paid fifty smackers for select 6SN7s.

This is the most conventional wisdom and a subject that the master Nobu Shishido took great relish in discussing with me, and why he had a passion for the very rare, very esoteric and out of production Western Electric 437 miniature triode, which are used in all of the WAVAC amplifiers. I recently paid $150 each for some 437s and 417s just to have them. As you know from Eric Barbour’s articles in Glass Audio, the weakest area in the current thermionic revolution is the lack of high quality miniature triodes....meaning that those 12AX7 and 6922s are not that cool. Want an insider secret...I don’t know a tube entrepreneur who isn’t trying to have high quality 12AX7s made. Will smooth plate Telefunkens ever return?

As the directly heated triode revolution grows you and I are realizing just how critical, the first quarter inch, the voltage/driver is to the success of our SETs. I have been aggravating about this subject on my web site, suggesting that MORE than the classic 6SN7 is needed (in it is various configurations) because we are learning more and more about the subtleties of these circuits. Have you noticed how quickly designers have shifted from the 12AX7, 12AU7, 12AT7 tubes to the octal varieties which are so superior they are JAN.....Joint Army/Navy tubes, which, because of the ending of the Cold War, are now available in truckloads. Even the Soviet military loved this tube which is why there are so many Sovtek 6SN7s around....again the politics of art. Now there are skads of higher quality 6SN7s available and everyone is rightly using them because they are electrically superior. There is only one reason to use the 9 pin miniature triodes...they are cheap. Eric Barbour, Svetlana’s thermionic-techno shaman has written and extremely important article about the hierarchy of small signal triodes in Glass Audio, Volume 9, # 6 which discusses this subject in detail. This is extremely important information. Check it out.

It shouldn’t surprise you that this notion of using the 6SN7 as a driver tube was popularized in Japan where SOP is 6SN7/300B, and for an interesting reason...empiricism. It is like mustard and hot-dogs. There are many octal dual triodes, just like the 6SN7, and many are direct substitutes. The combination of electrical superiority and the tonal quality of this genre of tube sets it apart from the 9 pin miniatures, because there is a family sound, just like the 300Bs, and there are good, better and best...just like the 300Bs, but there are no real you can get in the 12AX/T/U Family.

Am I suggesting that by simply switching to the new KR 10s that all of those amplifier that use 6SN7 will advance in shifting from Chinese 300Bs to KR 300BXLs? Read on Socrates.


Let’s get one thing straight job is to cause you pain and aggravation, not feed you putrid audio placebos. If I didn’t have enemies I wouldn’t be doing my job. If you want to read audio dribble written by custard sucking mamby pamby ex-yuppy scum audio pundits in pink tights you know what to read, so here is a double heavy dose of pain: The thermionic revolution is zooming ahead on two fronts, but there are still two areas of retardation, and you better be suffering because of it...because your job Job is to suffer. Isn’t suffering what this sport is all about?

300B polygamy is now legal and available to everyone. There are so many good 300Bs available at different price points, everyone can now join the exclusive club. Cool.

With the appearance of the new generation of KR directly heated triodes no one can belly ache that directly heated output tubes of absolutely the highest quality are not available. Because Count Kron has created a new directly heated triode vernacular I have labeled him the Beethoven of Triodes, and he, better than anyone else, knows that his superior tubes need a superior driver tube. The new Western Electric 300Bs are also a stupendous, but the KR tubes are now defining the outer edge of possibilities and no one...let me say that one yet has a clue about their ultimate expression..that’s how good they are. Have you noticed how many of the DIY amplifiers designers at the edge are creating circuits to exploit the unique qualities of these new generation of KR tubes, and they need superior driver circuits? Surf the web and you will get what I am saying.

No more complaints about output transformers...transformer artists in American, Japan, and Italy are offering us an enormous variety of the super high quality iron, and that includes the Magnequest re- innovation of "parallel-feed", and the new Plitron torroid single ended transformers, that I will report on shortly...and the new KR output transformers...glorious iron abounds. Hip-hip hooray!

I shall not relent on the feebleness of power supply design in America. What’s the problem here? It can’t be cost, because even the most expensive amplifiers don’t have properly designed power supplies! Boo, fart, burp. Just wait until I become President and pass The Federal Power Supply Standards Act.

We need for more advanced and subtler driver stages that will reveal deeper levels of directly heated triode cream. It is not that the driver stages that designers are using are not properly designed...they are.... within the "normal" context, but the world wide web has taught us that there is much more work to be done in this area, and that is why the KR 10 tube is such an important development. It is the driver tube we have longed for, and I speculate it is the driver tube that is essential for releasing the nascent magic of all 300Bs, and especially the high powered directly heated triodes and the higher powered KR tubes. The KR 10 is the first new dual triode design that has appeared, and it is not just an exact copy of a 6SN7, is it much more. The darkness is lifting.


A recent experiment which is one of the oldest and least used ideas in tube amplifiers, which was first brought to my attention by Ike Eisenson in the Audio Updates in the late 1970s, proves the point about advancing the input stage of amplifiers. This experiment took about 30 minutes to complete, and is now permanent. I connected an independent tube regulated power supply to the driver stage of both my single-ended 300B amps and Sun SV 300 MKII, which also have their own independent tube regulated power supplies for their output stages, creating two completely isolated tube regulated power for the input stage and one for the output stage.......and wham bang thank you Mam!

By totally isolating the voltage amp/driver stage power supply from the output stage power supply, I achieved improved transient response, clarity and made the lower octaves more solid, equally an expansion of the harmonic/space/time continuum in my home aural matrix. This is especially relevant in single-ended triode because improving the quality of the front end power supply improved the quality of the bass response, which is their weak point. No circuit alteration, just power supply isolation. I know you all know why this type of power supply isolation works: it is a low IQ no-brainer tweak of the highest order, and helped me discover a deeper level of the KR 300BXL magic musical cream.

A prediction: savvy solder slingers DIY tube artisan will start designing with separate power supplies for their input stages....just think about using one of those darling little tube rectifiers! It only takes another teeny beeny winding on your power transformer, or at the very least using a choke from your main B+ for isolation. For only a few dollars in parts you can achieve very significant results.

What is the point? We are not paying enough attention to the subtle qualities of the input stage of our amplifiers, and that includes push/pull. One of the reasons that I recommend subscribing to Costruire, the Italian audio magazine is this is the place where a great deal of serious attention is put into this subject. I also call your attention to the series of articles in Glass Audio, by Reid Welch, which discusses the piety of driver circuits for directly heated triodes. If you want to fully exploit this new KR-10 make sure it has a very high quality power supply because it demands it.


You can say the KR 10 is a 6SN7 on steroids, because it is designed to dissipate more current, swing much more voltage and needs more 6.3 Volt filament current, in the same way you can claim that the new KR 300BXL is a 300B on steroids. This analogy misses the whole point of how this tube will potentially push the envelop of harmonic cream, dynamism, and subtly. And why do I say potentially? Because in my rush to meet the deadline for this issue and alert you to this new development I haven’t had a chance to use them, which...ALERT, ALERT... will require us to rewire our input circuit because the tube pin connections are not exact substitutes for the 6SN7, and this tube again needs three times the filament current...1.8 amps. This tube is about 20% larger than a 6SN7 with much larger plates and looks very much like a chunky 5881.

There is a good reason for deviation. The KR 10 is not made like a 6SN7 or the 9 pin miniature triodes which have tiny little wires from their "guts" to the tube pins, The KR 10 uses much heavier and stiffer tube connection wire in its construction and this wire can’t be bent and moved around so that Count Kron must use a different pin layout. This is a good thing because that is what it takes to exploit its more advanced precision construction, including the very high vacuum in these tubes. I don’t want to bore you about KR’s advanced construction techniques, innovation in design, or the importance of the very high vacuum achieved.....but the reason why these tubes can achieve such high levels of performance...(remember...these are vacuum tubes...and all things being equal)..the higher the vacuum the better the performance, and longevity of the tube.

The reason I alert you to the larger current and voltage demands of the KR tube is that if you want to retro-fit this tube, be sure that the power supply of your amp can produce the extra current. I believe that most amplifier power supplies have the reserve, and this is like going from a two barrel carburetor to a supercharger on your Camaro. But again...if you are retrofitting be sure that your amp’s power supply can deliver the goods. Count Kron assures me that KR 10 can be operated up to 500 volts! Yikes.

Most miniature dual triodes are mass produced on "carousels" and there is a great deal of variation from one triode to another and from one tube to another, which is why every tube audio manufacturer goes through a sorting process to chuck 25% of the tubes that don’t make specs...which is what we did at New York Audio Labs. The KR 10s are made in the at hand made their output tubes and are very precision devices...and you have to pay for this level of is the price you pay for quality.

So how can I be sure that the KR 10 has the potential I assert when I haven’t used them yet (be on your guard)? (1) Count Kron is the concrescent genius of tube design and (2) Every KR tube that I use every day, and that includes the KR 2A3 and the KR 300BXL has a family trait, which makes sense because they are all from Count Kron’s gene pool, and I am assuming that the KR 10 has the same family, creamy, clear, very low in distortion, dynamic, complex yet subtle, and of the highest quality build. If you are not on the web go to your local library and read my various articles praising the KR power tubes. These are, like all of the KR tubes, beautiful hand crafted works of art, and holding them in your hand is like holding a jewel. If you own a solid state amp buy these tubes instead of a Cartier diamond for your girlfriend.

Do I sound like a KR salesmen? Are your eyes getting heavy and are you sliding into a dreamy state, wondering what these tubes will do for you amplifier? Let me shake you up and rattle you out of your triode dream state. Let me keep on huckstering and paint a picture for you that has a very wide and deep thermionic event horizon.

What if I told you that the KR 10 can be had in high, medium or low mu so that you can use it in any tube circuit from phono preamps, and...(sit down on your potty and buckle your safety belt) you can use them as an output tube? Like I said...just give this piece of piety a chance.

Vinylmaniacs have you ever heard a state of the art tube preamp that uses 6SN7s? Have any of you heard a state of the art line stage that uses 6SN7s? What about mic preamps with 6SN7s, or output stages of DACs? Can you imagine any of these with the high mu version of the KR 10? All of you push/pull pentode amplifier lovers, have you ever experienced a driver stage using these tubes? All of you smart thermionic techno-shamans who are, following in the footsteps of New York Audio Labs and, by designing hybrid tube/solid state amplifiers are you considering 6SN7s? Have any of you played with hybrid cascodes with a Fet on top of a 6SN7, or a tube current source connected to a 6SN7? Are you getting my drift...all of those classic tube designs that use miniature low or medium or high mu is time to move up to the creamier higher quality octal spread...improve the quality of that first quarter inch...and then if you understand this logical thermionic ascension and want to get even higher and higher, do the KR 10 which is probably the breakthrough, breakout in all of those circuits that are designed to amplify small signals.

Do you get my point? There is no need and no such thing as "new and better" in tube circuits. Just take those proven classic tube circuits and redesign them for the KR 10, and Voila, you are on the next highest plateau of ecstasy.


Can we come full circle know the mystical bagel of the audio arts. There is no better place to experience the dynamism of the current audio revolution (made possible by the world wide web) than in the arena of directly heated triodes. More passion and creativity can be found here than in any other place, and Count Riccardo Kron, as far as the Guildmeister of the Triode Guild is concerned, has challenged us all by creating a new thermionic vernacular. We need his KR 10 to release the nascent beauty of all directly heated triodes, and especially his tubes. We need the high mu version of the KR 10 to create a new generation of line stages and phono preamps. It will take years before we gain the skill to fathom full measure his achievement in tube design. The KR-10 is the key we have been missing. This new medium mu dual triode, is offering us heretofore undreamed of creative possibilities in tube amplifier design and by direct ontological implication expanded possibilities of musical ecstasy in our home...and what could be a better birthday gift than expanding the pleasure possible with the first quarter inch?

I am not now going to reveal some other awesome new creations the Count revealed to me because I have not yet received my PF Reader’s Liability Indemnification Insurance Policy that protects me in case of your heart fails from what I reveal. All that I can promise you is that just when you think you have gotten as high as you can get on Mt. Triode, the clouds clear and there is another higher peak way off in the distance, and as your telescope focuses you notice...there is Lawrence of Arabia beckoning. Be sure to check the Triode Guild web site for more thrills, spills and chills from the Czech Republic.


This is not easy to write because I am dancing while I am writing.

On my birthday I would like to ask the forgiveness of all of those who I have offended during the year. I was born a bad boy, and I will die a bad boy. I have been aggravating the orthodoxy since I was in kindergarten, and I figure I must have, beside brain damage, some kind of genetic damage from eating moldy salami sandwiches as a child. My astrologist told me I have only another five hundred years and ten life times left to figure all of this out, and I hope I make it.

On the other hand one of the great sources of joy this last year has been the contact I have made with my fellow revolutionary music aliens on the world wide web. Thank you for the poetry you sent me, sharing with me your beautiful works of audio art, your longings and your encouragement. Your passion and restless creativity is the audio revolution, and I am honored to dance by your side within the circle of life, and serve you. The sign above The Triode Guild says: Vita Nil Musica Subite Cum Pessimo Tuo, which translated from the Latin means...Life Is Nothing Without Music, So Get Down With Your Bad Self.

And of course I want to thank Count Riccardo and Eunice Kron for a great birthday celebration at their castle in the Czech Republic.

Over and out from Music HyperSpace

Dr. Gizmo

Costruire Magazine: Subscribe to this magazine because you will discover a completely new vernacular of tube design from a culture that, like the Japanese, is artistically refined, and this is reflected in their audio arts: Germani Ruscitto Comunicazione, Piazzale Loreto, 9-20131, Milano, Italy

KR TUBES/Ron Welborne: 303 470 6585 Fax 303 791 5783









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