tim jessup in front of Chicago live stage.

Dispelling the Myths of Digital Modeling

Dispelling the Myths of Digital Modeling

With Veteran Mixing Engineer Tim Jessup.

Well, how did we get here?

Recently I caught up with Tim Jessup at his mixing studio in Sedona, AZ. It was a studio like no other I’ve seen at that caliber. For starters, no mixing console to speak of, usually command-central for a sound engineer’s arsenal of exotic gadgetry. No sound-proof room either. A vintage Grand piano. Ok. Check that. Got the Grand piano thing going on. One studio artifact present.

As my eyes re-calibrated to the relative darkness, a good measure of vintage, tube-based contraptions came into focus. Black and grey metal panels with mysterious nobs and speedometer-like level indicators flanked both sides of Jessup’s nondescript swivel desk chair. More like devices filled two rows high across the deep end of his desk. In the center of it all was the new control-God. A souped-up Mac with three large display monitors.

Time Jessup's mixing station.

Tim Jessup’s seemingly modest mixing station. Featuring a late 2013 8 Core Mac Pro computer, with 64 GB of RAM, running Pro Tools HD Native, and three large thunderbolt displays. Additional DSP for the plug-ins is provided by three Universal Audio Thunderbolt Octo Cards and a Universal Audio Apollo interface, for a total of 28 Motorola Sharc chips powering the plug-ins. The main computer interface is a Black Lion Audio modified Avid Omni, featuring the latest BLA MkIII clocking. Various vintage hardware interfaces are seen nestled below and on his desktop.

It all reminded me of a scene in The Matrix whereby digital manipulation of reality is instigated through anachronistic rotary dial telephone pulses. “You mean to tell me all this shit is real?”

I was afraid that if I started with minutia, I might never escape it. Too tempting and risky anyway. So I decided to play it safe with big picture questions to disguise my ignorance.


As everyone knows, the mixing war of digital innovators versus analog purists has reached almost religious proportions. Who’s winning and where do you stand in the spectrum?


The war is over, actually. Digital modeling of analog gear crossed a nexus point just a few short years ago, where many of the new plug-ins and processors coming on the market today are virtually indistinguishable from their analog counter-parts. When I see distinguished Grammy Award winning engineers, fanatical long-time devotes of the pure analog signal path, trading in their $4,000 vintage processors in favor of the latest plug-in version of the same thing, it is quite obvious that, to some extent, they have come to trust digital modeling to provide the same character that they have come to depend on for many decades. This fact alone is astonishing to me. As for my own position on digital modeling, as always, you must first trust what your ears are telling you and not what the product marketing proclaims. Some models are more true to their analog counterparts than others. You can have five different versions of the same processor from five different manufacturers, and they will all sound different from one another.

Tim Jessup in the studio with Jazz guitarist virtuoso Stanley Jordan.

Tim Jessup in the studio with Jazz guitarist virtuoso Stanley Jordan. Tim recorded and mixed Jordan’s Grammy nominated album “State of Nature”.

They each provide slightly different “shades” of the coloring and character of the original hardware, depending on the depth of detail in the circuit modeling stage, and often in the DSP demands the model requires. However, its not really a matter of which is better any longer. These “variations on a theme” actually give us a broader spectrum of tools to work with, some more aggressive and obvious, some warmer, fatter, or more subtle and transparent. So depending on the style of music you are working with, it is now easier than ever to find just the right tool for the job. It is also, of course, a matter of personal preference. I have four different versions of the SSL mix buss compressor, from Waves, Slate Digital, Universal Audio, and SSL themselves. I use them all, but each in a completely different scenario, depending on how obvious or transparent I want the VCA compression character to be. To use a well worn-out descriptive, it depends on how much “glue” I want to inject into a mix.

But the biggest gain in digital modeling is of course cost, and it couldn’t have come about at a more opportune time, as recording budgets and music sales in general continue to decline. Even long-established “legacy” bands that have been around for 40+ years are finding that they need to tighten their belts, and be much more cost-effective when it comes to studio production. However, they each have a long established “sound” and a character that their fans have come to expect. Digital modeling enables legacy bands to produce new music that remains consistent with the sound they have established, without losing money in the process of recording a new album. It helps us adapt to the harsh economic realities of the music industry today, without compromising the final masters.

For new artists and engineers coming up in the business, digital modeling gives them access to high quality tools they might not have been able to get their hands on in the past. This will help them to grow their skill set and advance their own techniques much faster. I can think of no better way to develop someone’s talent than to give them access to the best tools the industry has depended on for decades. When you have the right tools for the job, mixing is no longer a struggle.


So what you’re saying is that digital modeling has reached parity with the analog devices they are emulating? That seems impossible to me. How can a virtual device be just as good as its hardware source counterpart?


As an outgrowth of modern digital programming and design, a new art form has emerged, which blends analog circuit design and digital coding. It requires extensive knowledge of digital programming, analog circuit design, and very discerning ears. Engineers in this field are reverse engineering analog hardware down to the individual component and the tolerances found in the original circuit designs, and then recreating the behavior of each component in the digital realm. The goal is to arrive at a complete model of the entire analog circuit path, including the behavior of transformers, resistors, capacitors, transistors, various types of vacuum tubes, etc. In the case of vintage digital devices, such as the AMS RMX-16 reverb or the EMT 250 from Universal Audio, the original algorithms and coding of the hardware are being imported from these devices so the model is an exact replica.


Universal Audio’s AMS RMX16-digital-reverg-plugin

The end result is a digital clone of the analog circuitry that gives these devices their unique character. The digital models respond to varying input signal level and generate harmonic distortion, cross-talk and other anomalies in the same dynamic way that the hardware does, particularly as the model is driven harder. This makes it possible to find the same “sweet spot” of tonality that one would listen for on the hardware. One of the big advantages of this type of modeling, is that it provides a consistent response and tonal character from one instance of a plug-in to another. In the analog world, generally, no two devices of the same model will ever sound exactly alike. Some units sound better than others, depending on age, maintenance history, capacitor condition, etc. So you can have two vintage UREI 1176 E series compressors from the early 1970’s that will sound quite different from one another. Whereas a digital plug-in of an 1176, modeled after a factory maintained “Golden Unit” will be absolutely consistent from one instance to another.

1176 Classic Limiter Plug-In Collection. Even looks like the original hardware.

1176 Classic Limiter Plug-In Collection.

Modeling analog devices down to the component level is all well and good, but what does it sound like? This is where the real magic happens. Entrepreneurs in this field, such as Steven Slate of Slate Digital, ultimately have to rely on their ears. Steven is a studio engineer and a producer himself, so he knows what the ideal sound is, that he prefers, for each of the analog devices his company models. Through an extensive series of listening tests, comparisons to the hardware, frequency cancellation analysis, and then going back and making a plethora of minor tweaks to the digital code, they eventually arrive at a plug-in that sounds and measures as indistinguishable from the original hardware.


Do you feel there will come a time when digital models will actually be superior to their analog counterparts?


In many ways, we are already there, which is why so many engineers are trading in much of their analog hardware today. The most obvious way this has already occurred is that every function of a digital plug-in can be automated. We can make them respond intentionally over the course of a mix, in ways that the hardware never could, such as automating compression thresholds on a vocal to prevent “pumping” during periods of heavy transients. Many digital devices are now being designed with a “balance” control on the output, which for instance enables internal parallel compression, without having to set up multiple channels to achieve the same result. Some manufacturers are now designing what I call “Frankenboxes” where they will blend certain characteristics of one device with another, such as Slate Digitals version of SSL’s VCA mix buss compressor, called the Grey compressor, which includes a model of the transformer from Neve’s mix buss compressor to achieve a fatter character than the original SSL processor.

Slate Digital FG-GREY

Slate Digital’s VBC (Virtual Buss Compressor Series) FG-Grey, what Jessup refers to affectionately as a “FrankenBox”.

This was a completely subjective design modification by the company to achieve what was considered to be a more pleasing tonal result. For a number of years, Waves Audio has been designing an “Artist Series” of plug-ins, which model entire chains of analog devices, based on the specs provided and listening tests done with certain well known and highly respected recording engineers. In a single control surface, the plug-ins give the user access to specific groups of devices that would typically define a particular engineer’s sound. Generally, each of these devices provides an optimized signal chain for a specific group of instruments, i.e. strings, acoustic instruments, drums, vocals, bass, electric guitars, etc. Design engineer Fabrice Gabriel has invented an entirely new concept in parametric EQ with his AirEQ design by Eiosis.

The AirEQ

The AirEQ designed by Fabrice Gabriel takes EQ beyond vintage analog sampling and into an entirely new way to sculpt sound.

The device has functions unlike any other traditional EQ, which include an instant band solo and sweep, with an adjustable narrow bandwidth and amplitude, which makes sweeping and finding offending frequencies incredibly fast and convenient. The AirEQ also allows for radical re-shaping of a particular band’s EQ curve, independently from the other bands, from a sharp narrow spike, to a rounded traditional shape, to a ruler flat peak. The AirEQ represents an entirely new way to sculpt sound.

So a trend has begun, in which designers are starting to think outside the box, as it were, and extend the capabilities of what were once static, “set it and forget it” processors. I see the design industry in a transitional period. Some companies, like Universal Audio, have a long history in designing and building world-class, industry standard hardware. They are at the forefront of digital modeling because of their deep history with analog circuit design, and they tend to stay very true to the original designs in their modeling. More than any other company, Universal Audio has a reputation for capturing the most accurate modeling of industry standard analog processors, and they have been continuously pushing the boundaries of what is possible, in terms of the realistic translation of analog character into the digital domain. Other companies have started to consider questions of “what if?”, and are allowing their imaginations to run outside the boundaries of traditional analog processing. It’s an exciting time to see what new tools are being imagined, and how this will ultimately transform the world of music production.


So let me raise the bar here. It seems like the technology is there to allow new virtual devices to no longer need to model an analog device at all. Of course, they wouldn’t be digital “models” anymore since they’re no longer modeling anything, quite literally. Do you see that happening and what would it look like?


With digital modeling, given enough DSP, anything is possible. So the limitations are only in the imagination of the designers. The pursuit of modeling that which already exists in the hardware world, is just the beginning, and it is helping to refine the techniques used to achieve the most realistic sonic results. It also makes sense from a financial perspective, because we engineers and producers tend to have a religious dogma about the processors we use. So we tend to invest our money in what is familiar, those processors that have helped us to create our successes through-out the years. In this way, traditional analog modeling is helping to finance design companies and ultimately, to enable them to start thinking and creating in new and unique ways. I can see digital modeling eventually following the path of computer graphics, where CGI is now enabling the creation of amazing imaginative worlds that look totally real on screen. We will eventually have models of “super-analog” devices that exaggerate the capabilities of traditional circuit components and their limitations, to provide tonalities previously unattainable with physical hardware. Imagine, for instance, a digital model of a giant, room sized 50,000 watt AM radio transmitter, with its enormous vacuum tubes, being incorporated into a model of an electric guitar pre-amplifier. Now that’s rockin’ !


Can you net all this out? A real-world example of how all this truly works in recording a album today?


At this point in music history, I think the most essential “real-world” contribution of digital modeling is economic. It is literally breathing life-support into a traditional music industry that is dying, and having to find new ways to thrive and remain profitable for artists, so they can continue to actually make a living creating and performing music. Gone are the days when it was a profitable investment for a band to book a lock-out session in a large commercial recording complex, and spend 5 –6 months recording an album for $300,000 or more. In reality, for most bands today, taking any time off the road to record a new album is a financial loss, as music sales and downloads represent only a small fraction of any established artist’s annual income today. So band’s like Chicago have had to become smarter, more cost-effective, in how they create new product. Caribou Ranch, where many of the band’s giant hits were recorded in the 1970’s, is now a private family retreat for the Walton’s, of Walmart fame. And Chicago, which still performs 150 shows a year, world-wide, cannot take time off of the road to make a new album. So we produce new material literally as the band travels, on tour.

Chicago Now, mixed by Jessup in Sedona, AZ, was recorded entirely when the band was on tour using resources that were already paid for, including arenas, hotel rooms, even the tour bus.

Chicago Now was recorded entirely while touring, using resources that were already paid for, including arenas, hotel rooms, even the tour bus. The album was recorded on “The Rig” which is a portable system that Jessup designed in Sedona. It is a scaled down version of Jessup’s Sedona studio, including the Black Lion modified Avid Omni interface. The album was mixed by Hank Linderman.

The technology has enabled us to get results that are equal or superior to the production values heard on the band’s 36 albums. Obviously, you cannot do a proper mix on a tour bus, so we also built a very cost effective mixing facility right here in Sedona, Arizona, where all the tracks from the road will end up. Our mix room depends largely on digital modeling to achieve the sound that the band is known for. I have models of virtually all of the outboard processing, the consoles, and the tape machines that the band has ever recorded with. So it is possible to emulate their vintage sound, to the extent that we choose. Mixing Chicago today involves a blend of vintage sounds, and contemporary processing as well. Digital modeling is at the heart of it all. Chicago’s most recent “studio” album, “Now” was recorded entirely on the road with the band’s portable Pro Tools HD rig, with tracks captured in hotel rooms, suites, hotel ball rooms at the Ritz, on the tour bus, with drums recorded on stage, after sound checks.

I just recently mixed a live recording of the band with members of the Chicago Symphony Orchestra at Symphony Hall in Chicago, at 192 kHz/24Bit in our Sedona facility. It is a very powerful mixing facility. Here we also did all of the sound design and the 5.1 mix for the band’s new documentary film “Now More Than Ever, The History of Chicago”, which recently won Best Picture in the 2016 Sedona International Film Festival

This is the future of recording, until such time that artists can actually make a reasonable living selling their music again. Without excellent digital modeling, this would not be a viable way to produce competitive new material. So modeling is quite literally saving the music industry from going the way of Steel Mills and manufacturing in the United States. More often than not these days, legacy bands will find themselves doing exactly what Chicago has done, in order to adapt and remain viable in this new economy. For Chicago it is working very well, as they celebrate their 2016 induction into the Rock and Roll Hall of Fame and their 50th Anniversary in 2017.

Topics in the next interview include, the “fix-it-in-the-mix” phenomenon, the 5-tool recording artist, and the undeniable sea change in the talent pool. We’ll also discuss the current trends and drivers in music today, and the many surrogates that are reshaping its fabric.

About Tim Jessup

tim jessup

Tim Jessup is the mix engineer for Chicago, wearing many hats which include: co-producer, film sound designer, dubbing mixer, recording engineer, studio designer, and studio manager. He is a 40+ year veteran of the recording industry, having worked as a staff engineer for a number of iconic studios, such as Kendun Recorders in Burbank, Artisan Sound Recorders in Hollywood, Wally Heider Studios in Hollywood, Glaser Sound Studios in Nashville, Bearsville Sound Studios in New York, and Olympia Studios in Munich, Germany.

Tim has gone full circle in his career, from recording hits with Quincy Jones, James Ingram, Christopher Cross, DeBarge, The Gap Band, the Isley Brothers, Gladys Knight, Devo, The Doobie Brothers and Chicago, to ADR for movie sound tracks from Disney, Fox Animation, Buena Vista and Paramount, to sound design and original music composition for major advertising campaigns from BBD&O, McCann-Erickson, Leo Burnett, and Saachi & Saachi, video game sound design with animators Don Bluth and Gary Goldman for Nintendo and Sony Playstation, to mixing front of house sound for Bobby Womack, Ashford and Simpson, and Domenic Miller (Sting).

In addition to his long studio career, Jessup is also a multi-instrumentalist and an arranger and has produced original music scores for film, advertising, and many recording artists. He is the recipient of more than 100 national awards, including the CLIO, numerous Telly and Addy Awards, The London International Award, and a Grammy nomination for Stanley Jordan’s album “State of Nature”. Jessup and director Peter Pardini recently won Best Picture for Chicago’s new documentary film, “Now More Than Ever, The History of Chicago”. For more information, go to Tim Jessup‘s website.

John Balla is an award winning digital marketer and technologist, journalist, writer, musician, and songwriter. He has consulted some of the largest software companies in the world, including Microsoft, IBM, XEROX PARC, and many others. A corporate dropout, John continues to consult tech startups and other entrepreneurial-minded companies on a variety of high-impact digital marketing strategies and initiatives. Unlike most strategic consultants, John actually executes on his recommendations, thus affording clients a seamless idea-to-results fulfillment cycle.

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