iZ RADAR: Converter

Most people who have ever had the pleasure of using an iZ Technology RADAR 24 [Tape Op #56] recorder know they are rock solid digital audio recorders, with an analog workflow and exceptionally high-quality sound. The first time I heard a RADAR 24 was in 2004, and I was blown away by how much better it sounded than any other commonly used digital recording device of that time. Somehow, the RADAR 24 had the musicality, depth, and smoothness of analog tape, but with the consistency, low noise, and clarity of digital. A few years later, I bought a RADAR 24 and used it primarily as an AD/DA converter for Pro Tools via ADAT. I compared it to many highly touted, expensive converters over the years and the RADAR 24 always won. When I bought a larger console, I needed more I/O, so begrudgingly, I invested in a 32-channel interface and put the old RADAR 24 aside. From the beginning, I could tell the new box sounded good, but not as good as the original RADAR 24, and I couldn’t help but wish that the company would come out with an AD/DA converter box with the same sound as the RADAR 24.

Recently, my wish was granted when iZ RADAR released the RADAR Converter. To clarify, the company iZ Technology (and Creation Technology) were makers of the original RADAR sold by Otari. The new company that makes the Converter is called iZ RADAR. The different name represents a change of ownership only – everyone who used to work at iZ Technology still works at iZ RADAR. This new offering is a modular AD/DA converter system that utilizes the same analog I/O cards found in the original RADAR 24 recorder into a DAW via a simple Dante chassis. Each Converter box is a half rack space unit and can hold up to two cards for either 8 or 16 channels of AD/DA via DB-25 connectors. Multiple units can be networked together via Dante protocol for large I/O counts, and each box has primary and secondary Dante connections for redundant streaming of audio on the network. In addition, Word Clock In and Out is present on BNC connectors for external clocking, and inside the chassis are DIP switches that allow for choosing different operating levels.

Upon unboxing the RADAR Converter chassis, it is apparent that they are simple and very well built. As a previous RADAR owner, I already had four Nyquist cards (three in the old RADAR 24 and one spare), and the first thing I wanted to do was compare the sound of the cards in my old RADAR 24 to the new Converter. Opening up the Converter box and installing a card was quite simple; however, getting the Dante network up and running was a bit more challenging. There are many Dante interfaces available, but in my experience, they vary significantly in quality. Audinate’s Dante Virtual Soundcard app uses the ethernet port on your computer and functions well for mixing and mastering. However, the latency doesn’t work well for tracking. With the hopes of achieving stable, low latency performance, I chose a Focusrite RedNet PCIeR Dante card mounted in an OWC Mercury Helios 3S PCIe chassis [see review this issue] connected to my 2018 Mac mini via Thunderbolt 3. All Dante devices are plugged into a managed network switch (with some configuration required), then Audinate’s free software controls the routing and set up of the Dante network devices.

After some research regarding proper set up, I was able to get the Dante network configured and running smoothly. The first thing I did was to compare the sound of a card in the new RADAR Converter via Dante to the sound of a card in my legacy RADAR 24 unit via ADAT. I routed eight tracks out to my console from the old RADAR 24/ADAT interface, played them back, and recorded the stereo mix. Then, I switched the cables over to the new Converter and duplicated the process. My observation is that they sound incredibly similar but not identical. I could not discern a difference in the low end at all. However, the new Converter seems to be a tiny bit clearer and less smeared than the old RADAR 24 in the upper mids. According to iZ RADAR, the cards in the new Dante box have slightly better THD (total harmonic distortion) and SNR (signal-to-noise ratio) compared to the older RADAR 24 system, and this might’ve been the difference I was hearing. However, they are so similar that I could not pick one from the other 100% of the time, and can’t definitively say that one sounds better than the other – the sonics are almost the same from a practical perspective. I am impressed that the new Converter chassis cards retain the sound of the original RADAR 24: a quality that I’ve come to greatly appreciate as time goes on.

Next, I wanted to see how the Focusrite RedNet PCIeR Dante card and RADAR Converter would perform together with respect to latency and stability under heavy DAW stress. I migrated the three cards from my original RADAR 24 into the two Converter chassis, giving me 32 I/O total. Adding another device to the Dante network is simple, so I was up and running quickly. First, I measured the roundtrip latency at 96 kHz using the 64 sample buffer setting in Pro Tools. To my delight, the Focusrite RedNet PCIeR card with the Converter measured a speedy 1.6 ms round trip latency – a number better than any other native interface I have used. With an exceptional round trip latency established, I then turned to investigate whether the system would be able to operate stably at low buffer settings with high track counts: 32 I/O active with dense amounts of plug-ins. I opened an existing session with a lot of tracks, plug-ins, and I/O, created 32 additional tracks, then sent audio to all of them, recording at 96 kHz. I ran the system for about three hours straight, occasionally stopping and starting record to gauge responsiveness, and the system never flinched. Since then, I have been running the Converter setup regularly for about three weeks, and it has been flawlessly stable with beautiful sonics – just like my legacy RADAR 24. One minor thing to note is that the Converter chassis has two small fans. Though the fans are whisper quiet, it may be noticeable at close distances in an exceptionally controlled listening environment. I have the Converters about ten feet from the control room listening position, and I can’t hear them at all unless I get within a few feet of the units.

Overall, I am incredibly impressed with the sound and performance of the RADAR Converter with the Focusrite RedNet PCIeR Dante card combination. The Converter maintains the superb RADAR sound many have come to love while at the same time condensing the size down to a half rack space per chassis (one rack space for 32 I/O) and incorporating modern Dante connectivity. In addition, the Focusrite Dante card allows for smooth, low latency performance and has been stable running at all sample rates using the lowest buffer settings in Pro Tools. So, whether you’re an existing RADAR 24 owner who wants to migrate older analog cards into an updated Dante chassis for use with a DAW, or anyone in search of world-class sounding converters with stable low latency, this combination is worth experiencing. As they say at iZ, “Nothing sounds like RADAR.”