Initially, the answers all seemed to point to the same bull’s-eye: As compact as possible, 8 channels, great Radial sound and built rugged to handle the road. The success we have been enjoying since the launch of the Radial ProD2 stereo keyboard DI formed the base. The ProD2 has two great sounding transformers that can effortlessly handle the dynamics of even the most aggressive digital piano. With a little redesign, we figured we could cram 8 channels into a single rack; this would be two more inputs than the JD6 so we felt confident that this would address the requests for higher density.

An interesting option was revealed when discussing stage set-ups with the techs on a John Mayer tour. They had two mixing consoles and two complete sets of keyboards, all connected to 16 Radial JDIs for complete redundant backup. With the JDI Merge (mix) function engaged, if a problem should ever occur, all they had to do was drop the levels on one console and turn up the backup and they were ‘live’. This of course got us thinking about redundant hookup, how effects should be routed and how all of these options would be best managed.

Where things started to diverge was when we asked about connectivity. Keyboard players that use full sized keyboards want front panel connections while players that use rack gear want rear panel – inside the rack – connections for their samplers and sound modules. Since there is no right answer, we opted to simply deliver both. We introduced the novel idea of rotating rack ears that would let the user determine whether the inputs should be on the front of the rack or inside.

We then decided that the best way to handle redundancy would be to add more jacks. We recently found some nifty stacking ¼” jacks that could do the trick. With four jacks on each channel, we have input-1, input-2, a thru-put and an insert jack to allow either input-A or input-B to share the same effects device… cool. This way you could have one dedicated effects device like a reverb on a keyboard and it would be able to be used on either input. We also figured some folks would like to send a dry (pre-effect) signal out while others may want a wet signal. So we added a 'pre' or 'post' effect routing switch on the inside so that the thru can be used as needed.

Next we looked at grounding. In live touring and in studio, you can sometimes be faced with all types of grounding problems, especially when you are interfacing multiple devices together. Folks generally use a passive DI box for keyboards because these tend to work best at eliminating buzz and hum problems due to ground loops. Challenges can appear when electronic devices are bonded together at different places which can sometimes exacerbate the opportunity for stray currents to flow between devices. To address these situations and to allow keyboard techs to configure the grounding scheme that best suits their needs, there are chassis ground lift switches inside the ProD8 for each channel. We even have a chassis to pin-1 ground on channel-1 that is side panel accessible.

So what is the verdict? It is all good! Herbie Hancock, Chick Corea, xxx have all purchased Radial ProD8s for their keyboard rigs and it has become our no.1 selling rack mount DI. We think you will be pleased!