TAKE US BACK TO YOUR BEGINNINGS AS AN AMP BUILDER.
I was playing drums in a blues-rock band called Martha’s Laundry with a guy named Dave Kessner, who played a Farfisa organ through a Sunn 200S. That amp flamed out gloriously one night, and he thought that was the end of it. But I fixed it, and two days later he said, “Let’s open a music store together.” I said, “What do we know about doing that?” Dave said, “Well, you can fix stuff and there’s big demand for that.” In 1967, he found what had been a Chinese grocery store in Berkeley [California] that we could rent for $75 a month, and that was the start of Prune Music. My electronics pit was the former meat locker. It had thick tongue-and-groove wooden walls with cork stuffing, and a huge refrigerator type door with a giant latching handle. I found out later that our bass player, whom women found particularly attractive, frequently used my carpeted bench for, shall we say “after hours” purposes. When we moved to Mill Valley in 1968, guess what? Another former grocery store with the old-fashioned meat locker. There was so much hanging out and partying in the back room of that place that I eventually moved my shop into an old Dog Kennel shack in Lagunitas, just to get my work done.
What led you to putting beefed-up power sections in small Fender amps?
I was repairing equipment for Country Joe and the Fish, and their roadies, Gary Jackson and David Faison, wanted to play a little joke on [lead guitarist] Barry Melton, so they said, “Can you do something to this little amplifier that’ll blow his mind?” I was into sports cars and had an underpowered Austin Healy Sprite that I’d always wanted to put an aluminum V8 in, so I decided that’s exactly what I was going to do to his Fender Princeton—in the form of a dual-6L6 circuit based on a 4x10 Fender Bassman. I knew the Princeton’s 10” speaker couldn’t handle the power, but I was able to fit a JBL D-120 12 in there if I aligned the spokes on the speaker just right. So the amp was totally stock looking and it blew Melton’s mind. That was the genesis of the first Boogie.
How did you get Santana to play it?
I knew the amp worked on the scope, but I wasn’t sure if it had any tone. So Carlos was hanging around the store that day and I asked him if he’d try the amp. He goes, “Man, I don’t want to play through a Princeton.” I told him I’d done something tricky to it, so he starts playing it and it sounds really good—it’s loud, and it has more gain and sustain than what he’d been used to—so he just went off on it. People were lining up outside and blocking the sidewalk listening to Carlos play, and when he was finished, he goes, “Man, that little thing really Boogies!” So that’s where the name came from. The process became known as getting your Princeton “Boogie-ized,” and I soon realized that I needed to put some kind of label on the amp because it looked like we were just selling Princetons. I had to learn how to silkscreen in order to make Boogie labels to go on the front panel and the grille, and the very first designs are what we started putting on the amplifier so people would know it wasn’t just a Princeton or a Champ.
Did your amp have the extra gain stage at the point?
No. It had more gain, but not the extra gain stage. That was an accident that happened with Lee Michaels, who was known for his Hammond stuff. He had this jones to get some Crown DC-300 amps, because they were the most powerful solid-state amplifiers you could get back then. Lee had expanded his B3 rig so that his Leslies where like four times the size with tons of power and a whole bunch of speakers, and he wanted to do that with a guitar rig. So he asked me if I could make him a preamp to use with the Crowns. I had no idea what it would take to make the Crowns work, so I started with my favorite Bassman circuit but figured I’d better cover the bases by adding another tube stage. To make it controllable, I also put in three level controls. We took it over to his studio and the first thing Lee did was plug the preamp straight into a 4x12 cab, which, of course, didn’t work. When I noticed this, we plugged it right with the preamp driving the Crown, which was now connected to the speakers. By this time everything was also turned up really high too, so Lee hits this big power chord and it felt like we got blown across the room! With the preamp set clean it was like the biggest Fender-style sound you’d ever heard, but you could also unleash a new realm of gain by turning up the first two controls and turning down the output level. Lee was just getting these hellacious crunch chords and endless sustain, and the thought occurred to me, “That’s what Carlos needs.” But instead of the Crowns, this preamp should be driving some 6L6s in the little 1x12 package I was pioneering at the time.
Essentially the concept for the Mark I, right?
Yes. A somewhat modified Fender circuit to which is added an additional 12AX7 gain stage, plus pots to adjust signal amplitude at three different places along the signal chain. At first, I put the added tube stage at the end of the chain, but that made it difficult to adjust for a clean sound. I remember one evening the idea bursting clearly in my mind: ‘The stacked stage should be at the front end, with a separate Input 2 jack after the overdriving Input 1 tube.” It seems so obvious now, as do many of the best solutions once they’re right there in front of you.”
How did you develop your tech skills?
Just by doing it. I never took any electronics courses, but I’d built ham radio stuff and read the RCA Tube Manual and the Radio Amateur’s Handbook as a kid. I didn’t understand a whole lot back then, but I was picking up the bits and pieces. And then as you’re working on it in a practical sense, more things start to fall into place. So really, it’s an accumulation process. I would have never thought to add that tube stage to the preamp for Lee if I had known what the specs were for driving the Crown power amp. If I’d known it needed three volts peakto- peak and low impedance, I would have done what everyone else did and it would have worked, but it wouldn’t have sounded good for guitar.
When you recently examined the Mark I that Santana used at Budokan in 1973, what were some of the things you noticed that account for its sound?
We were using paper-form transformer coils at the time—and still do—and that’s one of the deals. Because believe it or not, just like in speakers, the material that the wire is wound on completely influences how it sounds. It’s less hassle to use a flanged bobbin, but if you want it to sound vintage and musical, it’s got to be on a paper form. Another thing that’s really important is the grade of steel in the laminations of the transformer. There was kind of a weird grade on this particular batch of transformers that we’d used in Carlos’ amp; it was a lower quality iron, which gives a more vintage sound but is heavier. Also, on his Mark I, most of the resistors were carbon-comp, which was the industry standard back in the ’60s and ’70s.
How did the discoveries you made with his amp influence the design of the King Snake?
With most of our amplifiers, we go into great detail to suss out what kind of resistor we use in each part of the circuit. In duplicating the sound of Santana’s amp with the King Snake it was easy: We just did it the way that it was. Some of the resistor values in his amp weren’t spot-on—carbon- comps aren’t as precise to start with, and they vary much more when they age— so we took that into account. Capacitors were another thing too. We couldn’t get the exact same PVC caps, so we auditioned four or five different kinds until we found ones that sounded the same. All the others were either faster, slower, less complex, or more complex—same thing with resistors, all of which have their own signature sonic characteristics. The circuit layout also had some influence on it. We didn’t want to lay out the King Snake’s circuit the exact same way because the home-made printed circuit boards and the eyelet boards were too rudimentary, and wouldn’t have complied with some of today’s safety mandates. There was also one little section on his amp that wasn’t on a circuit board that I’d forgotten about, and that surprised me. But that’s because at the time I was still trying to decide what I was doing. Nevertheless, there were some peculiarities with his amp that influenced the way it sounded, and we made sure that we duplicated those things by comparing with Carlos’ amp to see what mattered, and making sure we were faithful to it.
Can you recreate an amp like Santana’s simply by using the same value components, or do other factors come into play?
Along with everything else, there’s a dynamic envelope that is also influenced by stuff that you would never suspect has any influence, yet it does. So once again, Santana’s amp had a couple of things in it that helped enhance the dynamic envelope. When he was telling me about his tone at Budokan, Carlos said every note goes “pop” and has this certain attack envelope, and he helped us to pin down what it was. We’d already come up with three fourths of the King Snake’s design, but there was one little thing we checked on his amp in a couple of different ways, and yep, it did contribute to that dynamic envelope where the notes sound round, fat, and musical. There was actually one part missing in Carlos’ amp, and I’m not surprised, as it was in a strange place where we don’t put them anymore. These are some of the refinements that have to be carefully built into each amp when it’s wired up. It’s all subtle but important stuff. There are some other things I can’t talk about because they are trade secrets that have to do with getting the harmonic overtones to line up in a certain way on all the amps we make. It’s one thing to build a golden amp, but it’s another thing to be able to build that gold into all of them.
How did you deal with the fact that Santana’s amp had an Altec speaker that’s no longer available?
Well, he has used a bunch of different speakers over the years. He was partial to Altecs for a long time, and he’s been using some that were re-coned, but he likes the Eminence speaker that we’ve been working on. It’s a premium stamped-frame speaker that’s in the vein of our golden-era Celestion references, and it handles distortion beautifully.
Was the chassis itself something you had to take into consideration for the King Snake?
Yes, because back in those days I was basically making the chassis myself and they weren’t as tall as later, when I added the graphic EQ sliders. Doug West pointed out that the old chassis had this archaic look, and I remember working hard to get that sloped front panel angled back. So we redid the first King Snake’s chassis to make it not only the same height, but also the same angle. It looks stubbier and cooler too, so I’m glad that we did it. Back in the day, I also had to drill, punch, and de-burr all the holes. I also had to learn how to do silk screening— not just to do the front panels, but also to screen the printed circuit boards. I was into PC boards because I wanted to get consistency of layout, and have everything in the right spot and not wandering around like you have when it’s wired point-to-point. So I’d buy sheets of printed circuit board material, tape up the circuit-board art work, have a silk screen made, screen the etch-resist on the copper, and then put it into a hot agitating acid tank that I built to etch the boards. Then I would drill the holes, stuff the parts, and solder it up. It was an extremely slow way to do it, but I was learning the processes firsthand, which I thought was interesting and important. Of course, I made the cabinets, both vinyl covered and hardwood, and wired the whole thing up. Eventually, after a minor accident with the etch acid, I found someone to fabricate the boards for me, but those early Boogies were as home made as you could possibly get.
Tell us about some of the King Snake’s new features
There’s a switch on the back that alternates between the two kinds of presence circuits that I was using back in the day. One of them was closely modeled after the Fender tweed Bassman and the other was essentially like a blackface Fender that’s been modded to have a presence control. In that case it’s not in the negative feedback loop, but is actually a high-frequency rolloff that works at the end of the preamp. Back when I was making the circuit boards, I would build a few amps with the tweed-style control until someone would say, “Man, that amp is bright.” So I’d go back and make a few the other way. So I alternated between them. Carlos has the blackface type in his Budokan amp, but the other Mark I that he’s been playing for many years has the tweed circuit. So on the King Snake—and this was another of Doug’s ideas—I made it so you can switch between both presence circuits. In the Tweed position the values are different and there’s less negative feedback, so the Presence control adds brights as you turn it up. In the Blackface position it will only take brights away. So it totally changes not just the Presence EQ, but the entire character of the amp.
You also added a 10-watt setting to the 60- and 100-watt options.
The 10-watt switch runs the two output tubes in a single-ended, class A parallel configuration so you can really crank up the master and get that class A tone without it being so loud. I have a patent on this. There was also a switch on the back of Carlos’ amp that I originally came up with as a mod for a Bay Area blues guitarist named Tim Kaihatsu, who went on to play in Robert Cray’s band. He had a brown Fender Deluxe that he wanted me to juice up for him, so I put a switch in it that alters the tone stack and puts back the gain that gets lost in the tone controls. I didn’t think much of it because it’s so simple, but he loved it, and pretty soon I was getting people asking me to get them that tone. It’s an important part of Santana’s Budokan snake tone too. But I didn’t want to have a switch hidden on the back of the King Snake, and I didn’t want to use a pull pot either; I just wanted to use the big oldstyle CTS 450 pots. So what I came up with, and I’ve applied for a patent on, is a way to dial the Middle control, so when you turn it from zero to noon it works like a normal mid control. But when you turn it up from noon, you get gradually increasing amounts of gain boosting in the last half of the rotation— up to where the old switch works. So now you can get adjustable gain boosting, which works great especially when you’re plugging into Input 2 or want mega gain at low volume from Input 1. The label on the pot now says Mid/Boost, so all you have to remember is if you normally set your Mid control on 5, you’d want to set it at 2 1/2 to get same response. Also, when nothing is plugged into the effects jacks, that circuit disappears entirely to remain faithful to the Budokan snake.
Can you still use an A/B box to switch between inputs on the King Snake, like you can with a Mark I?
Yes, but it’s functionality is still limited because there is only one master volume. The King Snake’s Master is now a dual-section pot, and switches taper according to which input jack is used to make adjustments easier. But we don’t want players thinking this is a fully channel-switching amplifier, because it isn’t. In that light, the Mark I really can be seen as the transitional amplifier, bridging the chasm between traditional and modern amps. It provided all the sonic capabilities, but didn’t offer the ability to preset and footswitch between clean and high-gain modes. That was achieved by the Mark II a few years later.