The Development of Virtual Circuitry Modeling Audio Effects
Physical modeling technology, a general term for software emulation of natural acoustic phenomena and electronic circuitry for use in musical instruments and audio effect processors, began at Yamaha in 1993 with the development of the VL1 Virtual Acoustic Synthesizer. At the time there were essentially no other electronic music products based on physical modeling, so the VL1 became the world’s first commercially available physical modeling synthesizer. Since the technology was being used to model acoustic phenomena, we referred to it as a “VA synthesis,” with “VA” standing for “Virtual Acoustic.”
K’s Lab, the team assembled to develop the VA tone generator, was established at the Yamaha research and development center under the leadership of Mr. Toshifumi Kunimoto (affectionately known as “Dr. K”) in 1987. The name “K’s Lab” actually came later, but Mr. Kunimoto has been and continues to be the driving force behind the development of physical modeling for Yamaha musical instruments and audio processing.
In addition to the virtual acoustic modeling used in the tone generator itself, physical circuitry modeling was applied in some elements of the VL1 effects as well. The VL1 was followed by the VP1 with physical modeling of string instruments, the AN1x with modeling of analog synthesis, and the EX5 and EX7 which combined algorithms from both the VL1 and AN1x with a range of new physical modeling concepts. The technology was constantly evolving and being refined at K’s Lab. The term “VCM” was first used to describe the modeling technology used in the “Add-on Effects” series of audio effects developed for a digital mixing console that was released in 2004. From that point onward K’s Lab has been devoted to developing physical modeling technology that effectively emulates a variety of audio effects, including the types of analog outboard processors used in recording studios and guitar processors, and implementing that technology in a wide range of products. In addition to independent processors, VCM technology is currently used in Yamaha MOTIF XS and XF synthesizers, CP series electronic pianos, and numerous other products.
In the next section we’ll take a look at the VCM based Vintage Open Deck effect that was original developed for Yamaha digital consoles.
The VCM technology based “Add-on Effects” series was initially released in 2004 as audio effects for Yamaha digital mixing consoles. Other effects in the series include the Comp276 and EQ601 effects created under the direction of recording engineer Shinichi Akagawa. All are highly regarded for their outstanding musicality. Figure 6 shows the Open Deck and Comp276 interfaces in the Studio Manager application that allows overall management of Yamaha digital mixing console data.
We arrived at Mr. Neve’s private residence on a summer day in 2007. In addition to conveying our strong desire to prove our technology by modeling an RND equalizer and compressor, we had done our homework and were well prepared. At the time we had already researched past and present equalizers, both stand-alone and console types, and had reached the point at which we could accurately model just about any analog equalizer ever made. What we actually had was more “know-how” than “technology.” There is simply no technology in the world, including sampling, that will accurately model all equalizers at the flip of a switch. It is not possible to capture and reproduce the characteristics of all vintage equalizers using one piece of software. Our experience had taught us that our know-how must be applied to individually optimize each model, and that considerable time and effort is required.
At that meeting at Mr. Neve’s residence we carefully described VCM technology and its background. As an example of the type of results that can only be achieved with VCM technology, we explained how the K’s Lab team had already succeeded in modeling the characteristics of a Neve equalizer that was popular in the ‘60s and ‘70s. We also explained that we were able to accurately digitally model the feedback type compression of the 33609 and other vintage compressors, which is a feat that few others had achieved. We brought that up because, judging by the specifications of the Portico 5043, we believed that Mr. Neve was partial to the feedback compression sound. It turned out that we were right, and Mr. Neve actually expressed his dissatisfaction with most current plug-in emulations of feedback type compression at the meeting. We also expressed our belief that modeling was only half the job, and that at K’s Lab we spared no effort in fitting and tuning our models to achieve the most musically appropriate sound.
The meeting was a success and our preparations paid off. That evening we received word that Mr. Neve would like to collaborate with Yamaha and K’s Lab. We subsequently learned that Mr. Neve had previously been approached by numerous developers and had rejected them all. The opportunity to collaborate with RND came to us because Mr. Neve understood that we not only had the technology to accurately emulate the measurable characteristics of analog gear, but that we were devoted to achieving the best possible sound as well. Without that understanding the collaboration between RND and Yamaha K’s Lab would not have begun.
Although the transfer function of the 4th order filter in the Portico 5033 equalizer has been carefully engineered to extremely demanding standards, approximating the filter’s characteristics using VCM technology was not difficult. Compare the response of the original analog filter and the VCM emulation in Figures 9 and 11, respectively.
Asked why the filter was originally designed that way, Mr. Neve explained that back in the ‘60s sound engineers needed to be able to adjust the mix balance to a degree after the tracks had been mixed to 2-track tape. The equalizer’s shelving filter was designed to allow the balance between guitar, bass, and drums, for example, to be adjusted in the stereo mix, and that same capability has proven to be a valuable tool for adjusting mix balance as well as refining individual tracks in today’s production environment as well. The basic design is timeless, and the talent that created it so long ago deserves our greatest respect.
Audio designers and manufacturers who also design their own transformers are a rarity, and the fact that Rupert Neve does just that – he began his career as an engineer at a transformer manufacturer – is another contributing factor to the “magic” of the Neve sound. He has always designed the transformers used in his gear, from the earliest Neve company products right up to the present day. The input and output transformers used in the Portico units are no exception, but they are not simply old designs rehashed. They are totally new designs that have been engineered to optimally support today’s sound. The same goes for all related circuitry as well, ensuring that the entire package is musically in tune with the times.
The amplifier circuitry, transformers, and peripheral circuitry, and the balance between them, are the cornerstone of the Portico sound. Mr. Neve describes that sound as having “depth and perspective.” Others refer to it as the “sweetness” that is so desirable in top-class analog equipment. All of the music, including the most delicate reverberations, is reproduced with care, as is the environment in which the sound was recorded. Mr. Neve pays meticulous attention to such details when designing any piece of analog gear, including the Portico series, and those details make up the core of the renowned Neve sound.
All of this meant that our most important mission at K’s Lab was not only to emulate frequency characteristics, but to achieve that “sweetness” in the digital format as well. We threw all of our resources and effort into realizing that all-important Portico depth and perspective in our modeling of the amplifiers and transformers. We started by using basic amplifier and transformer models that we had created for other effects, but were unable to accurately recreate the sound of the Portico circuitry and transformers. The problem was that the models were biased by the characteristics of components and circuits that were originally created with a different sonic approach to realize the tonality of different gears. So we started from scratch, creating a large number of new models and components using VCM technology, and trying out totally new methods wherever necessary. Evaluating each and every detail from both the engineering and sonic perspective, we began building a model and refining the parameters that could emulate the Portico sound. We would create a prototype, adjust, evaluate, and then go back to the prototype stage, and that cycle was repeated a great many times. More than thirty parts were created and discarded during the development process.
We eventually succeeded in creating a sound to which Mr. Neve gave his full approval. Directly comparing the original hardware and the model, Rupert Neve provided the following written evaluation:
“The behavior and response are identical. The performance and the sonic signature are accurately captured.”