Cranborne Audio: 500R8 500 Series Chassis & Interface

Cranborne was not an audio company I was familiar with. When first contacted about reviewing the 500R8, I was immediately intrigued. Here's why: the 500R8 is an 8-slot 500 Series rack and 28-in/30-out high-quality converter USB interface with a built-in discrete analog summing mixer. Standout features include zero-latency tracking, two headphone amps, a built-in monitor controller, plus loads of connectivity options like channel expanders and breakout boxes. It can be integrated into an existing studio, used as a standalone mobile recording set up, or simply as a standard 500 Series rack with so many more options. Yes, I was intrigued.

Cranborne Audio shipped the 500R8 with two of their Camden mic preamps [Tape Op #130] (not included with the purchase of the 500 Series rack). The Camdens have standard preamp controls but add a continuously variable knob that dials in an amount of what Cranborne calls "Mojo"; two different flavors of transformer coloration (Thump and Cream) achieved through a saturation circuit. The claimed frequency specs are impressive. Without Mojo engaged, the Camden is a very clean and clear preamp with low THD.

The 500 Series rack itself is well built, modules seat easily, and connections seem solid. On the 500R8's rear panel, XLR connectors handle the main I/O with TRS insert points on all eight channels. Each 500 Series module slot can be turned on or off with an easily accessible switch inside the unit. If you are using a module you switch the channel to On. If not, you can bypass it while still taking advantage of the 500R8's 8x2 summing functionality.

The AD/DA converter with a 121 dB (unweighted) signal-to-noise ratio and a master-reference grade internal ultra-low jitter (sub .5 picosecond) digital clock on the unit sounds great. I listened and tracked for long periods and found it to be uncolored and generally true to sources. You can also integrate your own converter as the master clock if desired.

I tested the 500R8 as a mobile rig by loading it up with preamp, EQ, and compressor modules. I then packed up the Cranborne into a small bag with some mics, cables, headphones, etc., and took it all to my house for a session with "anything with strings" master Danny Barnes. He wanted to track some 12 string guitar pieces he'd been working on, and it seemed like a great opportunity to get the 500R8 out of the studio in a remote scenario.

For this project, I installed some Burl B1D mic preamps [#111], a pair of Rupert Neve Designs 535 compressors [#133], and two Rupert Neve Designs 551 EQs [#134]. I simply connected the 500R8 to my MacBook Pro laptop via USB, then configured Pro Tools and my Mac – be sure to set session sample rate in the Audio/MIDI set up before you set it in your DAW. I did not do this the first go and had a session sample rate of 88.2 kHz with an internal sample rate of 44.1 kHz. Even though the session played back fine at the right speed through the 500R8, when I played it back with no interface it was chipmunks on seven double espressos because I'd actually recorded at the wrong sample rate.

I used my much-loved pair of Schoeps CMC-6 mics set up in X/Y configuration. These mics always sound amazing, and I have come to love them paired with the Burl preamps. Tracking was a snap, with no errors or crashes and no latency issues when we did a few vocal overdubs. To my ears, it was a stark contrast between the converter quality of the laptop and that of the 500R8. With rich and full sounding audio, monitoring through the Cranborne was much more enjoyable than through the Mac's internal converter.

For recording tracks back into the DAW, I created a stereo chain with EQs following compressors and utilizing the Chain feature on the 500R8. It was not a massive, complex mix by any stretch, but this simple bit of analog processing for the stereo mix was a cool option for a basic mobile rig. Danny and I both liked what we were hearing back, plus he loved the form factor and simplicity of the rig.

On the module section of the unit there are several function switches. Each module has a source switch that toggles the input between C.A.S.T. (more later), ANLG (analog), and USB sources. Mix Level and Pan controls for the built-in summing mixer are located directly below. The Chain switch sends the output of the preceding module to the input of the next. You can build creative processing chains this way –four stereo chains or any configuration you desire, up to one mega chain of eight modules.

The monitor section on the front panel is simple but functional. A standard feature set offers A/B speaker selection, mono and mute buttons, plus talkback controls (external mic required). Additionally, there are cool AUX and Monitor blend controls that combines the summing mixer with the DAW playback together into the AUX and monitor buses independently. A DAW 2 select switch assigns an alternate pair of playback returns into the Blend control for Aux and Monitor buses. The two headphone jacks (Aux and Monitor) finish off the section.

In addition to the previously mentioned XLR and TRS inserts (post module and pre-A/D) on each channel rear panel, the 500R8 offers tons of additional I/O options. Digital I/O includes S/PDIF, BNC Word Clock, MIDI, and USB 2.0. DIP switches control clock settings. Analog connections are provided for DAW 2 input (to be used as perhaps a click track or a cue mix from a stereo analog DAW output), talkback input, stereo Mix and Aux outputs, and two sets of speaker outputs. Also located on the back of the 500R8 are C.A.S.T. inputs on every channel for Cranbourne's breakout boxes (C.A.S.T. = Cat 5 Analogue Signal Transport). These N22 breakout boxes are 2-channel mic input devices that can be connected to the 500R8's mic preamps via CAT5 cables with runs up to 300 feet. They are also making N22H breakout box units that have a monitor section so that a musician can be listening to and setting their own level for the mix while tracking with no additional headphone systems. So, you can run eight mic lines (over CAT5e, CAT6, or CAT7 cables) to various locations around a studio, house, church, barn, or whatever – plus each module has monitoring capabilities! All controls remain on the preamp with the unit's operator.

I hope to explore this unit more thoroughly in the upcoming weeks to unlock more of its features and functionality. Every "studio head" friend that comes by and sees the unit is immediately intrigued and impressed by its sonics, form factor, and capabilities. I enjoyed working with a little less, in terms of gear. Swapping a few modules in and out for tracking and mixing forced me to make choices in terms of tone, but also kept things relatively simple which had me thinking about what I really needed for a specific project or song.

The 500R8 can be used as part of your existing studio setup, be a great mobile rig option, or a standalone (along with a computer, of course) recording solution for those that either already have some 500 Series modules or wish to start building a collection. When you factor in the option of adding Cranborne's 500ADAT expansion unit for 16-channel functionality, this gets attractive! It truly is a very well thought out mini-studio that packs a ton of punch with has loads of flexibility and expandability.