Reverb Interview: Mark Bartel and the Tone King Imperial MKII

From afar, there's something markedly classic yet undeniably modern about Tone King amps. It's that '50s TV aesthetic matched with the glowing panache of a new boutique amp. Once plugged-in and warmed-up, this balance between old and new is superbly maintained: absolutely classic tones with the best modern tools and reliability.

It's this sweet spot between vintage sound and contemporary quality that's made Tone King one of the go-to boutique brands over the past couple decades. For many discerning players, finding and maintaining a vintage guitar that can keep up through jam sessions, recording projects and shows is easy. Finding a genuine vintage amp that can run the same gauntlet? Not so much. For this reason, pairing your prized guitar with a boutique option that delivers the timeless tones you crave is a no-brainer.

This year at Winter NAMM, Mark Bartel and Tone King unveiled a new version of their flagship Imperial combo, the amp that started it all back in 1992. Watch our video demo below and read on for Mark's explanation of the Imperial MKII as well as what goes into designing the world class Tone King amp line.

Reverb: It's been over 20 years since the first Imperial. What prompted you to go back? What needed improvement?

Until recently, we had been building both the standard Imperial, and the 20th Anniversary Imperial. The 20th Anniversary model was to be a limited edition, and the time had come to end the run. This gave me the opportunity to consolidate these two models, and apply some developments I had come up with over the years.

One thing I wanted to include in the MK II was the “handwired board” construction that used on the Royalist. It's kind of a hybrid approach combining the advantages of handwiring with the layout flexibility of PC boards. Most of the electronic components are mounted to a flat board, but all signal wiring of any significant length is done with handwired cables and jumpers. This scheme allows me better control over component placement and wire routing, and results in less wiring length overall and better component placement when compared to most handwired arrangements. I really think this is a superior way to build an amp.

Another thing that I wanted to include was the Ironman II attenuator, which I had been experimenting with for a while. This included a neat bypass feature which began as a customer request, but it worked so nicely that I made it a standard feature.

Onboard attenuation is a great example of how Tone King amps embrace new ideas. For some of our readers who are less familiar with attenuators, what are the advantages of having one built into the amp? How does the new Iron Man II achieve this?

To me, the best kind of guitar tone involves simply plugging the guitar straight into an amp with a simple, direct signal path, and cranking it up to full output for natural tube overdrive. Unfortunately, volume expectations are different these days than they were in the '70s, and this is just not practical for most people anymore. I first got involved with attenuator design when it became clear that most of my customers were just not able to crank up their amps and get them into the ‘sweet spot’ where they sound their best. After experimenting with lots of different schemes for reducing volume level, I decided that a well designed attenuator was the least offensive method. It preserves the critical balance of gain among stages of the amp, and allows the output tubes to operate as they should, which I think is critical to maintaining the ‘feel’ of the amp.

I put a lot of effort into the original Ironman attenuator, and it turned out great. It was an over-the-top, proof of concept design that was quite complex and included 5 large custom transformers. I found a way to scale that design down to fit inside an amp chassis, and have been including it in all of my new amps ever since. Aside from the convenience, one advantage to a built-in attenuator is that it can be tuned to perform particular amplifier circuit and speaker chosen for that amp.

The Imperial also has onboard Reverb and Tremolo. How do these circuits and sound compare to classic 'verbs and trems we all know?

Reverb and Trem are about the only effects I ever use, so they’ve got to be excellent. I like my reverb sound to be on the vintage side – shimmery and deep, but with plenty of genuine spring pan character. I don’t want it to sound like a perfect studio reverb. I want it to sound like the real thing – splashy when you hit it hard, shimmery when you back off.

I don’t want it to sound like a perfect studio reverb. I want it to sound like the real thing – splashy when you hit it hard, shimmery when you back off.

I like my tremolo sound to be smooth and rounded, but not necessarily technically perfect modulation – it needs some nonlinearity to give it some authentic mojo. I use the old “bias modulation” method in the Imperial and Sky King to get this kind of sound. It’s a primitive method, but it has the right sound to me.

Do you have any tips for particular settings on the Imperial that might work best with different types of guitars and pickups?

The Imperial is fairly easy to dial in. I don’t like to include a lot of switches and dials that radically alter the tone. I like to make it easy, so you can plug in and get a good sound without messing around too much.

If you are playing a Strat, I’d try these three basic settings to get a feel for what this amp sounds like:

1. Clean rhythm: rhythm channel, vol=4, treble=4, bass=6
2. Clean rhythm with a bit of edge: rhythm channel, vol=6, treble=4.5, bass=6
3. Fat edgy roadhouse rhythm: lead chan, vol=4, tone=3, mid_bite=1
4. Hot tweed cranked up: lead chan, vol=8, tone=3, mid-bite=8

Here are the same sounds, but dialed in with a Les Paul:

1. Clean rhythm: rhythm channel, vol=2, treble=4.5, bass=5
2. Clean rhythm with a bit of edge: rhythm channel, vol=3, treble=4.5, bass=5.5
3. Fat edgy roadhouse rhythm: lead chan, vol=2, tone=3.5, mid_bite=1
4. Hot tweed cranked up: lead chan, vol=3, tone=3, mid-bite=9

The Imperial along with other Tone King amps uses a specially designed, unique speaker. What goes into the process of selecting and designing a speaker to match your amp design? What do you look for in speakers?

When I designed the Imperial, I needed a speaker that could cover a wider range of tones than most. It had to deliver a nice BF Fender clean sound, but also have enough growl and punch for a hot tweed / early Marshall sound. I worked with Eminence and they developed the speaker we’re still using today.

To me, the key is the synergy between the speaker and the cabinet. A good sounding speaker can be awful in the wrong cabinet, and vice versa. When I design a new amp, the cabinet design and speaker choice happen together.

Back when I designed the Comet amp, in the 90s, I remember building literally more than 100 test cabinets to get the sound I wanted, and had a custom speaker commissioned for that design as well.

Nowdays, I have enough experience from past work that I can usually get in the ballpark on the first few test cabinets. I still begin by designing the cabinet. After tuning the cabinet through a few iterations, with various speakers, the speaker choice becomes fairly obvious. Once the speaker choice is made, I’ll run through a dozen or so more test cabinets to work out the fine details, and settle on the final design.

Since the original Imperial, you've ventured into a few new areas including more British-like amps such as the Royalist. Are there any other eras or styles of amps you see yourself looking to for inspiration in the future?

The Royalist project was a lot of fun, and I’m still delighted with that amp. I’ve always been a big fan of Marshall amps. That’s the sound I grew up with. I’ve wanted to develop an amp in that style for along time, but was hesitant to take it on until I thought I could do right.

At the moment, I don’t have any specific plans to take on another iconic sound like I did with the Royalist. I’ve been revisiting some of the sounds that I found inspiring way back in the beginning – funky old “pre-tweed” amps that really had a lot of vibe and character. I kind of worked in that direction with the Falcon, but I think there’s more that can be done with designs that bring back the raw roots of early tube amps.

As guitar gear and sound processing equipment becomes more complex and more integrated with computer systems, my taste seems to be going in the opposite direction, to the authentic vibe of early tube amps.

What has been the biggest breakthrough for your amp designs to come about since the first Imperial was introduced?

Quite a bit of design work has happened since the Imperial. In general, I prefer to approach design from engineering perspective, and often start off with a blank sheet of paper and come up with my own ideas for solving design problems. I honor the work done by the designers of the classic vintage amps we all know and love, but I don’t feel bound to repeat their work by cloning their designs. Even when the intention is to design an amp with a genuinely authentic vintage sound, there are cases where some innovation can get you closer to what I see as the ideal for a particular sound. A perfect example of that is the Royalist, which I think does a great job of capturing the essence of the JTM45 sound, but the circuitry is certainly not a clone of a JTM45 circuit.

I think the area of design with the greatest frontier still ahead is attenuator design. Attenuators are certainly not new, but the vast majority have been simple resistive loads that didn’t do such a great job at preserving the tone and feel of a cranked amp. Nowdays there are a number of units out there with reactive loads of varying quality, which do a much better job. However, I think that there is still room for innovation that will get us even closer to the goal of preserving the experience of playing a cranked amp, but at low volume.

I think the work I’ve done with the Ironman and now the Ironman II is probably the closest thing to a breakthrough that I can claim. The Ironman II includes circuitry to correct for the way the ear perceives sound differently at different volumes (i.e. per the Fletcher-Munson curve), and I haven’t seen this done before. It also includes some hard- to-describe circuitry which controls the damping factor as seen by the speaker to help it perform more naturally at very low volume.

Another area where I think I’ve made some useful progress is cabinet design. As far back as the Imperial, I at least recognized the huge contribution the cabinet itself makes to the overall tone of an amp, and did my best to develop a cabinet that helped make the Imperial sound the way I wanted it to. Now, 20+ years and several hundred test cabinets later, I have a much better understanding of how even minor details of construction affect certain tonal characteristics, but I still learn something new every time I design a new cabinet.

Bonus question I like to ask everyone: What is your all time favorite recorded guitar tone?

Tough question.

I always thought this was one of the greatest. The sound quality isn’t great, but you can get a sense of how incredible this must have sounded in the studio.

Aside from that, this is a tone I can’t stop listening to lately. Deke always sounds great, but the tone on this one is just so over the top – my kind of thing.