How To Design A 500 Series Mobile Analog Rig

As producers and engineers in the modern world, we have a wide range of options when it comes to recording. The rapid advancement of home recording technology has allowed us to work in ways previous generations of audio professionals could never dream of. Today’s open landscape of recording technology has trickled down to artistry and creativity as well, enabling artists to record in places that were unthinkable just 30 years ago.

With advanced and powerful home recording technology, we are no longer tied to big box studios in order to create studio-quality records. They can be made almost anywhere, and there are many fascinating stories of records being made in strange or far-off locations. You always have to be ready to catch that lightning in a bottle whenever it strikes, and most importantly, wherever it strikes. It is not uncommon for an artist to rent out an exotic Airbnb for a month or two out in the wilderness to stimulate those creative juices, and you as the producer or engineer have to be prepared to capture the magic even in the most unideal situations.

In most cases, a laptop, an interface, and a handful of good mics can more than suffice for the majority of mobile recording work. However, sometimes fully in-the-box rigs leave something to be desired in terms of immediacy and color. Traveling with a full-size rack full of outboard is possible, but it can be a little too cumbersome unless you have a truck or a crew of roadies. Thankfully, there is an option available today with its roots in the past, and its face towards the future.

The History 500 Series Modules

The 500 Series format got its start in 1968 when Automated Processes Incorporated (API) founder Saul Walker created a completely modular system for his early recording consoles. Not only did this make repairs and troubleshooting a breeze, but it also allowed for the easy customization of consoles according to the needs of recording studios at the time. Many of the options could be chosen a la carte and implemented very easily and quickly without having to design entirely new circuits and layouts to match the requests of discerning clients.

The 500 Series stuck around since then, mostly behind the scenes, but things really started to get interesting around the mid-2000s, when smaller companies began developing modules for the format. In the years that followed, bigger companies such as Neve, SSL, and many others took note of the widespread popularity of the format and began developing products for it, opening the floodgates for all manner of products, both big and small, to be adapted and developed for the format.

Today, the 500 Series format gives you a very wide palette of sound to paint with and offers flexibility and portability unlike ever before. A rack of outboard that could take up the whole wall of a traditional studio is available in a 3U 19” chassis, which is truly incredible, even by modern standards.

In the spirit of mobility, we put together a portable recording rig, with a primary focus on creating a high-end analog tracking front end, with gear choices made to be similar to what you would find in a typical studio setup. This basic topology can be applied to your needs as you see fit, but this layout should give you a good starting point to customize to your needs. Also included are choices for interface, patchbay, power, and a 6U rack case, so this can be a complete self-contained analog tracking powerhouse, designed for exotic tracking gigs and less-than-ideal situations that require that extra character and color.

PREAMPS

Neve 1073LB (x2)

We’ve opted here for two Neve 1073LB preamps, due to their flexibility for use on many different sources, as well as their classic sound to excel in tracking situations. We recommend two so they can be used as a stereo pair for something like drum overheads, or individually for a vocal and guitar.

BONUS FEATURE: The combi-jack on the front allows you to quickly plug in and take down ideas or go DI without a second thought to capture that lightning in a bottle without fuss.

API 312 (x1)

For the second preamp flavor, we suggest a single API 312. This is a classic preamp with a rock-solid build and a punchy, mid-forward sound. It adds a lot to the versatility of this rig, and does best with transient-heavy material. In a tracking session, you can reach for the 312 for a mono drum overheard or an electric guitar, or even a shouty vocalist with a lot of dynamic range, as this preamp performs well when being driven slightly.

BONUS FEATURE: An added benefit to this specific unit over others is the 3:1 output transformer selection, which adds more options for coloration than cleaner preamps may provide.

Retro Instruments 500PRE (x1)

It's important to include at least one tube preamp in your rig, and the Retro Instruments 500Pre is the best option in terms of being conservative with rack space and tonality. It's based on the Retro Instruments Sta-Level compressor (also offered by Retro in 19” rack form) and serves up warm, colorful, and larger-than-life tube sound to any source you throw at it. It's fantastic for just about anything you can think of, and using the high-gain switch can yield some complex and rich saturation for recording gritty DI electric guitars or bass.

BONUS FEATURE: The 500Pre acts as a type of limiter at signals above +18dBu, so you’re almost getting two units in one. Since it shares some of the Sta-Level DNA this could be great for soft-limiting vocals, or even running stems through to add some warmth and weight.

DYNAMICS

IGS Audio 576 Blue Stripe (x1)

The IGS Audio 576 is a unique take on the classic 1176 Revision A “Blue Stripe” style compression. Known for being grittier and more characterful than the later circuit revisions of the 1176, it’s a tracking favorite amongst many engineers. When it comes to 1176-style compressors, the IGS is a solid choice,not only because of its small form factor, but it’s cost-effectiveness as well. If you’re familiar with the 1176 circuit, you know it excels on nearly every source, and having at least one in a rack is almost a necessity.

BONUS FEATURE: You have the ability to stereo link two 576s, so if you decide to go with two for your rig, that adds a lot to the versatility of this unit.

Smart Research CL1A (x1)

Even though the Smart Research CL1A is based on the classic SSL stereo bus compressor circuit, it's become a bona fide classic in its own right. This compressor is often colloquially referred to as the “glue compressor” amongst its adherents, and its abilities as a mixing compressor are well known. However, when tracking, this compressor works wonderfully on vocals, bass, and especially drums. It can also be used to process stems, or to “Brauerize” your entire tracking session.

BONUS FEATURE: Being dual mono as well, you can use both channels independently, so you’re really getting two compressors in one (although the settings stay the same for each channel). It also has controls for external dual sidechain control, which really expands the palette of this device.

EQ

API 550A (x2)

One of the most ubiquitous and well-loved EQ circuits in history, the classic API 550A is really the grandparent of the entire 500 Series format, and no mobile rig based on that topology would be complete without one. We suggest a pair of API 550As in this mobile tracking rig, as they're a total Swiss army knife of EQ, without ever sounding sterile or boring. They were chosen for this rig because of their incredible versatility, and the depth they add to every source.

BONUS FEATURE: Having two stepped EQs means that it could work great on a master bus, and I’ve seen engineers chain two 550As together, and boost a fundamental frequency of a bass or kick drum to really make it stand out.

Pultec EQP-500X (x1)

Those who have used the big Pultecs know they are totally addicting. This is a fascinating take on that classic circuit; it opts to use a genuine API 2520 op-amp as opposed to the original tube circuitry, which not only shrinks the form factor considerably, but also adds clarity and tightness to the sound. The standard frequencies are all here, with the added 16 kHz boost that is favored amongst users of the original EQP1-A.

BONUS FEATURE: The “boost and cut” Pultec trick works well on the EQP-500X as well, which thickens up kick drums and basses considerably.

UTILITIES

Universal Audio Apollo x8p

This is a classic Thunderbolt interface from Universal Audio, which not only gives you plenty of I/O for your 500 Series rack, but also includes eight channels of UA’s incredible Unison preamps, and access to the complete gamut of the UAD plugin line, so if you run out of real estate on the hardware side of this rig, you can run the crème de la crème of analog-modeled plugins with almost zero latency.

Black Lion Audio PBR-TRS

Since you’re going to be working with a lot of analog and digital I/O, a patch bay is almost a necessity to facilitate easy and quick signal routing. This is a modest option, but those who want to be on the cutting edge can opt for something like the Flock Audio Patch LT, which is a completely self-contained, digitally controlled patching system that has a fantastic workflow.

Furman PL PRO-C

An often-overlooked part of any rig, clean power is something to be picky about, especially when traveling to remote destinations with possibly shoddy wiring and power grids. This is not only a great solution to power this rig and everything else you may need with its generous amperage, it also has a front-facing USB port to power any devices that you may have, and a voltmeter to keep your eye on.

SKB 1SKB-R6S 6U Rack Case

A rugged rack case that can survive the rigors of the road, this SKB is perfect for easy teardown and set up, without compromising at all on toughness and security of your rack.

If you’re interested in purchasing any of the gear mentioned in this blog or have questions about other 500 Series products, contact a Vintage King Audio Consultant via email or by phone at 866.644.0160.