The amp wizards: how Reinhold Bogner, Paul Rivera, Michael Soldano and Jose Arrendondo advanced amp technology, and gave the world great tone

When you walk into your local Guitar Center or Sam Ash in need of a high gain amp, or an amp with channel switching, or an amp that can handle the thunderous bottom end of a seven or eight string guitar, chances are pretty good you can find what you’re looking for. This wasn’t always the case.

For many years, guitar players were demanding more than their stock amps could give them. Why couldn’t they get a great, distorted sound without cranking their amp to oblivion? Why couldn’t their amp have more gain, or switchable channels? Why can’t they replicate the tones of their favorite players?

But if you had the cash, and knew who to look up, or knew someone who could hook you up, you could see a tone wizard that would “mod” or “hot rod” your amp, and help you capture the tones you were chasing. Once these amp gurus became overloaded with work, most of them took the next step by starting their own companies, and as time has proven, their designs and innovations have shaped the amps of today, and continue to shape the amps of tomorrow.

The amp gurus who founded their own high quality companies include Reinhold Bogner, Paul Rivera, Michael Soldano, and the most recent to enter the arena, Mark Cameron, who formerly worked for Bogner. And no story like this would be complete without one of the original amp wizards from back in the day, the late Jose Arredondo, who because of his relationship with Eddie Van Halen enjoyed an incredible late life success story.

There are no college courses on how to build a great amp. The tone masters featured in this story learned from trial and error, musician input, and gut instinct. Now they’re willing to share with Guitar World what they’ve learned along the way.

Speaking with the amp wizards featured in this article, one thing is clear. There was no organized plan among any of them to take over the world of tone. Many started out naively tinkering with electronics, having no idea it would one day lead them to running their own companies.

There weren’t amp mod guys in the late-Sixties, but there was of course amp repair, which is what Paul Rivera’s business grew out of. Rivera was modifying amplifiers as early as 1968 in New York. As he recalls, “In my first shop, this guy came to me who was a big Leslie West and Eric Clapton fan, and he asked me, ‘How can I get that sound?’ He played through a Fender Twin, and it was loud and clean, but it didn’t really have that much gain and distortion unless you’d modify the output stage. That’s how you start, from the requests of musicians.” (In 1971, Randall Smith started modding amps, and his small, woodshed business eventually grew into Mesa Boogie.)

Rivera is one of the only amp wizards with electronics schooling, but he says, “The only thing you learn in school is fundamentals. You can learn various formulas, but that doesn’t tell you how to make something sound good. That’s something that’s done from your own research, and trial and error.” Rivera also learned a lot when he worked as an apprentice in New York recording studio as a teenager. “Working on recording consoles teaches you a tremendous amount about audio,” he says. “That kind of background helped a lot in training my ears.”

Rivera settled in Hollywood, California in late 1975, and word of mouth from musician to musician made his business snowball from there. “I was doing mods for studio cats like Jay Graydon and Dean Parks in L.A., but I also got turned on to a lot of session cats in New York and Nashville. Chet Atkins had heard about me from Larry Carlton, and once I did a mod for Chet, then the Nashville cats called. I was very fortunate in the early days to be in places where we had great musicians, and I had their ears.”

By 1980, Rivera was hired by Fender to help bring the company back to life. “I brought my mods into Fender, and spun them into a lot of the amplifiers they made during my tenure there. The problem was, how do you work for a company, get to be creative, get to design products, and enjoy yourself in that creative sense? It’s very hard to find an outlet for that in a corporate environment.”

While working at Fender, Rivera learned a lot about marketing, manufacturing and distribution, and by 1984, when he was in his early thirties, the time was right to leave and start his own company. “I thought, If I don’t do it now, I probably won’t, so…let me do it!” [laughs]

As with many amp wizards, necessity is what drove Mike Soldano to seek great tone. As he relates, “The whole beauty of American ingenuity is that if something’s not doing what you want it to do the way it is, you can figure out a way to do it better, or do it differently. So I applied that same ethic to guitar amps, and it worked.”

At first, Soldano built his own guitars because “at the time I couldn’t find a guitar that really played the way I wanted it to, and I just couldn’t buy an amp that had the sound I wanted. At the time, I still had the big dream of being a rock star, and I was trying to get this killer guitar sound that nobody else had.”

Soldano had taken high school physics courses, but when he tried to further his electronics education at a local community college, the teacher told him, “Nobody’s doing tubes anymore. We’re doing solid-state stuff now. If you took this course, we’d probably touch on it for five minutes, and that’s it.”

“Being the Mr. Do-It-Yourself I’ve always been, I thought I’d just go to the library,” Soldano continues. “There’s gotta be books on this.” Soldano then dove into old tube reference books, and Navy electronics manuals. “It’s pretty dry reading, but I learned how vacuum tubes worked, and all the things you need to know to do engineering.” Soldano then bought an oscilloscope at a pawn shop, and worked on friend’s amps at night while working at an auto body shop during the day.

It’s hard to believe today, but as Soldano remembers, Marshalls weren’t easy to come by when he was growing up in Seattle. “If a guy had a Marshall, he was the cool guy on the block because they were expensive,” he says. “Seattle was a blue collar town back then, and most of the guys that played around here didn’t have a ton of money, so they had old Fender Bassmans, or Fender Twins.” But this proved fortuitous for Soldano when he was learning to modify amps. “50 watt Bassmen were dirty cheap back then, and it was the easiest amp to mod. You could tear into one of those, and not feel bad about it.”

Soldano knew that a great high gain sound at any volume was obtainable, but it was proving elusive. Eventually, he found the key. “What everybody was doing prior to what I was doing was you took one tube, you hit it really hard, and got a lot of gain out of that one tube, then use that to overdrive the entire amp.”

For Soldano’s amps, “There’s a lot of tubes that are doing the gain, but no one tube that’s doing very much gain. It’s like you’re driving a car with a six speed. You’re gently going from first, to second, to third, to fourth, to fifth, to sixth gear, and you’re slowly ramping up all the gain through a lot of stages, whereas other amps were doing it from first gear to high gear. They’d get all their gain in one, big jerky lurch, where I was kind of finessing it.”

And instead of overloading the power section of the amp, “My whole deal from day one was I wanted to get it all in the preamp, because I wanted to be able to have this thing sound just as good at any volume. I wanted to be to turn it down, and play in my living room, and still have the same tone when I went to a club and cranked the thing up."

Soldano was “a total headbanger at the time,” and called his standard amp modification the “Metal Master” mod. Soldano then took what he learned from modding amps into his own amp design, the Super Lead Overdrive, or the SLO. Although he was going for a metal vibe, the SLO “turned out to be a much more versatile amp than that because there were other guitarists playing through it that were better than I was, and they could expand on its usefulness.”

After leaving Seattle for Los Angeles, Soldano opened his own shop in Hollywood on April Fool’s Day, 1987. “I had no idea how to run a business,” Soldano says. “I didn’t know if I was gonna make it or not, I was just going for it on youthful ambition.” Two years later, Reinhold Bogner would make a similar journey to Los Angeles himself…

As a teenager growing up in Germany, Reinhold Bogner also began building his own amps because he couldn’t afford to buy one. His father was an engineer, and his passion was collecting old tube radios. “Electronics were around the house all my life,” Bogner says. “I didn’t have the money to buy an amp, so I tried to make an amp from parts my father had laying around.”

In developing his own amps, Bogner tried to emulate the tones of his favorite players, like Rory Gallagher, Gary Moore, and Angus Young, from listening to their albums. Trying to replicate those tones at a low volume was also a necessity. Whenever Reinhold played too loud, his father would go to the fuse box and shut off the electricity to his room.

Once Bogner was happy with the sounds he was getting, local players started bringing over their amps. “It wasn’t a plan, it just happened,” Bogner says. Once he was in his early twenties, Bogner realized he could only go so far in his native homeland and wondered, Okay, what’s next? Then he modified a Marshall for Kansas guitarist Rich Williams, the first somewhat known player Bogner worked for, and Williams told him, “Man, you should go to L.A.”

Then Bogner read about Andy Brauer, who rented boutique gear to every hot guitarist under the sun. So with a Marshall he modified under his arm, and about $600 in his pockets, Reinhold headed out to Los Angeles in 1989, hoping Brauer would give him a job. “For some reason, I just knew it would work out,” Bogner recalls. Once Brauer heard Bogner’s Marshall, he told Reinhold he could start that Monday.

Once Soldano and Bogner set up shop in L.A., they didn’t have to wait long for players to beat down their doors. The SLO attracted a wide variety of great players including Eric Clapton, Warren Haynes, Eric Johnson, Warren DiMartini, Steve Lukather, and Eddie Van Halen, among countless others.

At Andy Brauer’s shop, Bogner first mods were for Steve Stevens, studio legend Michael Landau, and Dave Jerden, who was producing Facelift, the debut album from Alice in Chains. Once the world was punched in the face by the brutal tone Jerry Cantrell got from Bogner’s modified Marshall, the floodgates opened, and Slayer, Megadeth, and Anthrax soon came knocking as well. Not to mention Eddie Van Halen bought the modified Marshall Bogner brought with him to the States for $600 and one of Ed’s guitars.

From modifying Marshalls, Bogner then created his first rack mount pre-amp, the Triple Giant, then the Fish model. “A preamp was easier to do because I didn’t have the resources at the time to do a whole amp,” Bogner says. “Also at the time, preamps were kind of like the hip thing.” But once preamps started dying out, Bogner created his first full blown amp, the Ecstasy, which took a year to develop, and came out at the end of 1992.

“The idea was not just to make a single channel or a two channel amp,” says Bogner Amplification co-owner Jorg Dorschner. “Reinhold went for a three channel amp with tons of options on it so everybody could customize their amp. You can take it from a basic vintage Marshall kind of tone, to a hot-rod modified high gain sound.”

“It’s easier to make one channel sound great, but it’s really hard to make a two or three channel amp, and have each channel sound good in one amp,” says Bogner. “I think I put those two things together, not just the high gain sound, but also the flexibility.”

Before you could track down and order everything on the internet, keeping a new amp company well stocked wasn’t easy. “Back then it was a lot of footwork,” says Dorschner. “Checking out companies to do the sheet metal work, going to little electronics stores to source parts, going through catalogs, calling people on the phone…it was tremendous work to find out where to get stuff.”

After the Ecstasy, other models would follow including the Shiva, the Metropolis, and the Uberschall, which is Bogner’s most recent example of player research and development shaping an amp. The Uberschall, Bogner’s ultra high-gain amp that’s perfect for drop tuning and deep low end, was influenced not by a big name guitarist, but John Ziegler, from a local L.A. band called Volto. “Amps can have a particular player who influences them, and sometimes, it’s not even a famous guy. John was just a local guy I know, and players like that are more accessible, more easy going.

“I usually try to come up with something I like for myself,” Bogner continues. “If I can make something I like, and expand on it so others like it too, that’s usually my goal. If I don’t feel it, or don’t get it myself, then I’m not comfortable with that, and I can’t put my name on it. Sometimes it takes me a while, and the Uberschall was the first amplifier I had a bit of a problem with. John told me, ‘I need more bass, more gain,’ I said, ‘What are you crazy?’ ‘No, no, you need more.’ We tried it, he started playing through it, and it sounded good. He was right. That was the first time I didn’t feel it from the beginning, but now I understand it, I feel it.”

Rivera also entered the down-tuned world with his Knucklehead model, and his Powered Sub cabinets, that can handle extreme bottom end. Rivera loves the variety of players he’s worked with over the years, and says, “To me, the biggest error an amp guy can make is thinking he knows it all in terms of what something’s supposed to sound like. You box yourself into a particular tone, and it precludes you from learning and growing, and creating new products for players.”

Once bands like Korn and SlipKnot came to Rivera, he was excited to work with something new. “You talk to these cats, ‘What do you want?’ ‘Well, here are the kinds of chords I’m playing…’ Then you realize, ‘Oh my God, these guys are playing in drop-A! How are we gonna do it? How are we gonna get speaker cabinets to do this?’ Then you start scratching your brains, and create something. That’s the fun part, and I just hope it keeps going and people keep coming up with new things.”

Except for Lee Jackson, who modified amps for Paul Gilbert, George Lynch, Steve Vai, and Zakk Wylde, and Caesar Diaz, who gained fame as Stevie Ray Vaughn’s tone doctor, the amp wizards usually didn’t advertise, preferring to let their tones speak for themselves, and let their businesses grow by word of mouth.

One of the most mysterious amp wizards was the late Jose Arredondo, who is both one of the most well known, and at the same time unknowable, tone gurus in history. He didn’t save his secrets for future generations, and trying to track down any biographical information, or any of his amp secrets, is like trying to catch fog in a butterfly net.

Although Arredondo worked for Vox, (he had a hand in their Super Beatle amps), and for Ampeg, where Paul Rivera believes he knew him from, he was of course best known for reportedly working on Eddie Van Halen’s amps. If Van Halen mentioned he used Charmin toilet paper, it would have put their sales through the roof, and sure enough, once he started dropping Jose’s name, Arredondo was modifying Marshalls like crazy.

In recent years, Van Halen has maintained that Arredondo didn’t really mod his amps, he just mentioned Jose’s name to help out his business. Whether Arredondo did or didn’t hot rod Ed’s amps, Jose did have many satisfied customers, including James Hetfield, Vai, and John Sykes, among many others.

Bryan Jay, who played guitar in the ‘80’s metal band Keel, had a Marshall modified by Jose, and recalled that even back in Arredondo’s hey-day, he wasn’t the easiest guy to track down. “You had to know somebody that knew somebody that knew him to get a hold of him,” Jay recalls. “Thinking back, [my mod] was kind of difficult to get.”

Jay, and Keel’s second guitarist Marc Ferrari, got in touch with Jose through Keel’s management, and they brought over two brand new, fifty watt Marshalls. Jose usually didn’t work on fifty watt models, and Bryan and Marc’s were two of the first he modified. “I don’t know this for a fact, but I think what it was because of the transformers,” says Jay. “What he did was he took old transformers, old parts out of old Marshalls, and put ‘em in the new ones, he’d modify them. And I think the 50 watts didn’t go back that far, so he couldn’t get those parts.”

Jose had a shop, Arrco Electronics, but Jay recalls going with Ferrari to Arredondo’s home (both were in the San Fernando Valley). As they arrived in a regular middle class neighborhood, Jay wondered, Is this it? When a man who looked to be in his sixties answered the door, again Jay thought, We don’t have the right place. But once it was clear the man was expecting them and invited them in, it was indeed Jose.

In Arredondo’s garage, Jay saw several Marshalls sitting around with name tags on them: George Lynch, Yngwie Malmsteen, Jake E. Lee. “Oh, you’re doing an amp for Yngwie?,” which apparently was another fifty watt Marshall Jose was working on. Although Arredondo was a friendly and talkative guy, he never talked about what he was doing with anyone else’s amps. “He was very secretive,” says Jay.

Although Jose was much older than the musicians he worked for, “He was definitely young at heart,” Jay recalls. “Definitely had some fire in him.” Arredondo was from Argentina, and he spoke with a heavy accent that at times was hard to understand, but when it came to tone, there were no communication problems. “What I basically wanted was that kind of that first Van Halen album sound, and he seemed to know exactly what I wanted.”

When Jay picked his amp up several weeks later, he was very pleased with the results. “We’d put up different amps in our rehearsal studio, play through this one, switch to that one, and the Jose always blew everything away. It was unbelievable how good it sounded.” Jose gave the amp an extra pre-amp tube, as well as a pull knob. “When you pulled the knob out, it dropped the volume, but you still had all this gain,” Jay says. “It sounded like it was on ten.” (John Sykes reportedly has this same mod).

Arredondo didn’t live long enough to have his own model amp on the market, but ironically, an amp based on Jay’s Jose modified Marshall was released, the Peavey VTM.

“The Vice President of Peavey was best buddies with one of our managers,” says Jay. “They wanted us to use their equipment because they were real big on the country side, but they were really trying to break into the rock world. They said if they borrowed the Jose amp, designed an amp that sounded as good or better, would we use it? We said okay. They took it apart, saw what he did, and modeled the VTM after it. They didn’t know the amp was based on a Jose modified Marshall.”

As for the Marshalls that Jose modified over the years, they remain as elusive as the man himself. Anyone who still owns one has a rare, and valuable, commodity. “I know you could get a good penny for it,” says Jay. “I remember somebody offering me like $15,000 for the thing. Now I feel like I should have sold it for that, but I never would have seen it again.”

Jay did end up selling his Jose Marshall to a friend, so he knows where it is if he ever gets the urge to play through it again, “And I know he won’t sell it.”

At first many amp wizards were secretive about what made their products great, and often for good reason. “There was a lot of competition, which drove that secrecy,” says Soldano. Rivera says one of his former techs copied one of his six position “fat switch” mod, and used it in other companies he’s worked for, and Soldano says his circuitry design has been ripped off by two major amp companies.

But looking back today, Soldano says, “It never hurt my business. I was really worried that it would, but I still sell as many amps as I can build. If I was doing bigger volume, I might be worried about all this stuff, but there’s still purists who want my amps, they know it’s hand built in America, and they know they’re getting a certain level of quality.”

Bogner says, “Nowadays, most people have two or three amps, one from him, one from me, so it’s kind of immature to be insecure about this. A great artist needs many colors, that’s why I think there’s space for everybody.”

Some amp designers will tell you that with schematics and amp secrets popping up on the internet, it takes away the magic of what makes an amp special. But what truly can’t be replicated or copied is an amp creator’s personal touch. “It’s not magic, it’s pretty much just physics,” says Soldano. “The key is how you do it, because we all put our own personal twist, or signature, on it.” Or as Rivera puts it, “Our personalities come out in our products.”

Bogner says he’s never felt he’s had to keep anything about his amps hidden, that there’s no magic in making a great amp. “If you ask me what’s the secret sauce, there isn’t any.” It’s attention to detail, a little thing here, a little thing there, and the details all add up. It’s putting a lot of love, labor and passion into it.”

The innovations that the amp wizards developed over the years certainly woke the major companies up in a big way. “You can see Marshall caught on,” says Bogner. “They brought out a four channel amp, but it’s a give and take. We started out taking stuff from Marshall and expanding on it, now Marshall’s expanding our stuff, so in a way it’s good, the competition keeps it somewhat fresh.”

Soldano also feels the quality and care the boutique companies put into their amps has made the big companies re-examine their own quality control. “You really learn from modding and repairing amps when you see the mechanical and electrical failures of other manufacturers,” says Rivera. “Pop open my amps and see what we use for parts. We don’t compromise; it’s not worth it. Pay now or pay later. Pay now with high quality parts, you won’t have to pay later with warranty claims, and making a bad reputation for your company.”

As for the next step in amp innovation, Bogner doesn’t feel it will be with tubes. “I will be really surprised if there’s something really new and different coming out through tube technology,” he says. Bogner recently took the big step of creating a combination tube/solid-state amp with Line 6, which could be the first stage of a new generation of amps.

“The next thing I see happening is modeling companies trying to find a new sound that can’t be done with regular old-school technology,” Bogner says. “It’s just a matter of time with some of the big companies. I think they’re scared. You have to have guts in a big company to do that. As a small company, you’re more likely to take that step.”

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