Reinhold Bogner on the Future of Amps, Part 2

Reinhold BognerAfter more than 25 years in the business, legendary tube-amp guru Reinhold Bogner knows what it takes to get great tone. Read on to learn his secrets, and see what challenges he overcame while co-creating the DT amp series.

What makes a great amp? How do you create amps that musicians love to play?

There’s a lot of things that are unexplored and unexplainable. Sometimes you come across an amp, and it’s just like, ‘wow, this one’s a good one.’ It’s like when somebody puts together a guitar, and maybe that tree was just grown right, in the right season, and the right spot of Earth’s magnetics and voilà. And there’s some of that esoteric stuff with tube amplifiers, too.

I’m very scientifically oriented, but I know our scientific vocabulary and our physics understanding is limited. We think we know it all, but certain things, you can put them under a spectrum analyzer and you won’t see a difference… but you hear the difference. Sometimes it’s easy to produce the effects, but they’re very hard to measure. Or you can measure the effect, but you cannot measure the cause.

And so it is with amplifiers. That’s why I don’t measure too much. Of course, you measure the voltage, and you measure certain things that you want to go out of range of the component specs, but with most of this stuff you just have to play it. And you hear it and how it feels. That’s the ultimate thing that you can’t replace with an analyzer. That’s why it’s important to play guitar, you have to understand the vocabulary of guitar players, and you have to feel it.

Any other secrets that you can share with us?

My secret is paying attention to the all the details, every little thing. The last percent you want to squeeze out of a project takes the longest, but if you add up those little half percents over 30 years, you come up with something that makes the difference.

At the same time, you need to see the whole picture. Like some musicians they have such great ears, but they can never enjoy music. At a certain point, it stands in your way. They never finish a record. I got sucked into that world for a while too. But now I understand that you have to see the overall project and you have to let it go. At a certain point, it just becomes, like, “Dude, when are we going to start making music?”

Tell us about the goal of creating the DT amp series.

The idea was to combine my expertise in the sound and flexibility of guitar amplifiers with Line 6’s expertise in cutting-edge technology. We wanted to create something that represents the best of both worlds—that nobody else has ever done before. There hadn’t been anything that combined tube power amp sections with HD technology to get maximum flexibility with keeping the tonal qualities. You couldn’t just do it in analog, you’d have to make too many compromises.

What were the biggest challenges in getting a single amp to produce so many different voicings?

To get each DT voicing, we played with three parameters: feedback topology, power supply and biasing. Each parameter has certain variations, you know, the feedback topology has four, the power supply has two (saggy and tight), and the biasing has two (Class A, Class A/B). You can mix them up in various ways, so we have different combinations for each of the four topologies. Any combination of them makes a huge difference, so that’s how we achieve those really dramatic characteristics of the feel and sonic experience of the power amp.

It took a while to get all of those parameters to work in the right ratio. Also what’s really hard to do is to make it reliable. Switching high voltages and things like that is not so easy to do in a reliable and stable way. And you don’t want to have huge popping and noises. It really took some work. And that’s probably why it hadn’t been done before.

Learn more about DT50 and DT25

Read Part I of the interview