Innerclock Systems GridLock II

Can a MIDI interface really make a difference? Innerclock Systems think so.

Australia’s Innerclock Systems have been around for 20 years, but you may never have heard of them. They specialise in a niche corner of the music technology market: MIDI timing and synchronisation. They obsess over jitter, port alignment and sample accuracy, and create tools that work to eliminate the timing problems inherent in music production.

Until now, they have mainly focused on MIDI clock generators. The GridLock II promises a lot more: it is their new flagship MIDI interface. In fact, Innerclock Systems are billing it as the first ever “professional” MIDI interface. Why?

Well, there are certainly a lot of ports, both USB and 5‑pin. It supports 5‑pin MIDI, USB MIDI, DIN‑Sync and CV/Gate. There are also some very impressive specs on timing, which promise event, clock and port‑to‑port accuracy to within a few microseconds. The customisable firmware allows you to create virtual OS system ports for each instrument in your studio. Then there’s the clock generation, which also promises frightening accuracy, and, crucially, the ability to shift clocks independently across all available ports so that all your externally clocked gear is perfectly in sync. In short, it might be the most over‑engineered MIDI interface ever made.

Hardware

Let’s look at the physicals first. The GridLock II is a desktop USB 3 MIDI interface with ports on the front and back. It can also be rackmounted using a custom 19‑inch rackmounting kit. It’s a fairly chunky unit measuring 190 x 235 x 70mm. On the rear are eight 5‑pin DIN ports. These can carry any MIDI or DIN‑Sync data, switchable per port. There is also a pair of DB25 connectors for the optional VTX‑1 Eurorack CV breakout box, which provides 16 CV outputs. Innerclock tell me that additional breakout box formats are coming.

Around the front, you’ll find eight more 5‑pin DIN ports. Four are MIDI outputs, two are MIDI inputs, and two are dedicated DIN‑Sync outputs. You’ll also find two USB‑A 2.0 ports and two USB‑B 2.0 ports. The two USB‑A ports will support powered hubs, allowing you to connect up to four USB devices each. The USB‑B ports are host ports, enabling you to connect to another computer or hardware device that supports host connections, such as an iPad or a modern Akai MPC. Each host connection will provide four new virtual ports on the host. There is also a dedicated headphone output that provides an accurate click track. Perfect for drummers or anyone needing a reference clock.

On the GridLock II’s back panel we find a USB‑B port, another eight 5‑pin DIN sockets, and two DB25 connectors for connecting optional breakout boxes.

Between the physical and USB MIDI ports, there are a potential 28 MIDI outputs (eight of which are switchable to DIN‑Sync), 10 MIDI inputs, and two dedicated DIN‑Sync outputs. Plus 16 CV outputs. That should be enough to drive any small to medium‑sized studio, but if you need more, you can connect up to four units, for a total of 112 MIDI outputs, 40 MIDI inputs and 64 CV outputs. Innerclock claim the port‑to‑port alignment across the entire system is accurate to a few microseconds, which is seriously impressive.

To connect the GridLock II to your computer, you need a USB 3 connection and a pair of spare audio outputs on your audio interface. The audio outputs provide a sample‑accurate analogue clock via the included GridLock II plug‑in (available in VST3, AU and AAX formats). The GridLock II converts this audio clock to latency‑free MIDI clock, DIN‑Sync and voltage clock signals. You assign a track containing the plug‑in to your spare audio outputs, and GridLock II will take care of the rest.

The point of having GridLock II generate the clock, instead of the DAW, is that it eliminates DAW‑specific timing and latency issues. Also, every port can have different clock divisions, swing and time shifting, which means you can compensate for any instrument’s inherent lag by shifting the clock so that each one is perfectly aligned to the grid. It’s a very impressive system. There is nothing quite like having multiple drum machines and sequencers running in perfect lock‑step.

Software

The main configuration of GridLock II is done through the GridLock II Control application. Sorry, Windows users, but for now, it’s Mac‑only. Installation is quick and easy, and if you have your GridLock II connected, the Control app allows you to customise all manner of things by completely rewriting the GridLock II’s internal firmware.

The GridLock II Control software is where you can configure GridLock II to rule all of your MIDI gear.

Let me give you an example. Let’s say you have a Yamaha DX7 that you use as a master keyboard, but you also want to sequence it with your DAW. In this case, you would connect the MIDI output of the DX7 to a MIDI RX port on the front of the GridLock II, and the MIDI input of the DX7 to one of the MIDI TX ports on the rear. In the GridLock II Control application, you create a new instrument with a custom name, ‘Yamaha DX7’, and assign those two ports to the instrument. Then, you configure the ports, specifying whether they send MIDI clock, or filter MIDI data such as aftertouch or SysEx.

Once you save this new configuration, the GridLock II firmware is rewritten, and suddenly your DAW will detect a new MIDI input and output port, beautifully named ‘Yamaha DX7’. A specific port for every instrument!

Let’s now add a MIDI sequencer, such as an Elektron Digitakt. The Elektron boxes have USB MIDI, so we’ll use the USB‑A connector on the GridLock II (you can use a four‑port hub here to connect up to four MIDI devices to the same USB port). In the GridLock II Control application, we create another instrument, name it ‘Elektron Digitakt’, assign it to the first USB‑A port, enable MIDI clock (because we want the sequencer to play with the DAW), and save the session again.

Now, your DAW will display two additional MIDI ports with the custom ‘Elektron Digitakt’ name. When you use the GridLock plug‑in in your DAW, the Digitakt will lock perfectly in time. If, for any reason, the sync isn’t perfectly in time, you can use the GridLock II’s clock shift function to move the clock relative to the DAW grid, just for that instrument. You can shift in 10‑microsecond increments, for total accuracy, and in divisions of the DAW grid (16ths) for more rhythmically creative offsets. While you’re there, why not experiment with the swing and clock rate PPQ divisions, which can dramatically change the feel and speed of the Digitakt clocking.

Let’s add a CV‑based instrument, such as a Roland SH‑101 or a Eurorack modular. With the VTX‑1 Eurorack breakout module connected to the DB25 connector on the GridLock II, you can configure each of the 16 mini‑jack outputs as Gate, CV, Trigger, Clock or Transport. As before, we create a ‘Roland SH‑101’ instrument in the Control application and add some Voltage ports: one each for gate, pitch and clock (to have the SH‑101 sequencer play along when needed). Gates can be V‑Trig or S‑Trig. Amplitude can be 5, 10, 12 or 15 Volts (try getting a 15V signal from a typical DC‑coupled audio interface!). CV signals can be V/Oct or Hz/V, with custom pitch scaling, pitch‑bend support, velocity support or MIDI CC binding. Analogue clocks are fully configurable too.

Once the configuration is saved again, the SH‑101 appears as another MIDI port in the DAW. The GridLock II hardware is doing all the heavy lifting of converting the MIDI to CV signals needed for the SH‑101. This handling of MIDI and CV instruments together, all with the super‑precision and zero‑latency timing, is a minor miracle. And it’s all DAW‑agnostic. The ports are systemwide, so every piece of MIDI software benefits.

One last example. Let’s say you have another computer, or a mobile device such as an iPad. As long as the device supports class‑compliant MIDI, you can connect it to the USB‑B ports on the GridLock II and create another instrument. Now you can sequence your iPad, or second laptop, from the main DAW just like the rest of the studio, even clocking DAWs to each other.

Once you have these instruments fully configured, each with its own dedicated MIDI port(s) in your DAW, you can merrily use the DX7 to play any of the other instruments, whilst anything that is set to output MIDI clock (or DIN‑Sync / Voltage Clocks) will sync effortlessly every time you start and stop the DAW transport.

The GridLock II has a built‑in routing page and a virtual patchbay for all instruments. Create a routing path from the Digitakt to the DX7 and the SH‑101, save the firmware again, and you can happily sequence those instruments from the Digitakt without needing a DAW. And because all these configurations (including the routing) are saved to the GridLock II firmware, they are persistent through reboots. That means you can take the GridLock II onto the stage and use it as a central MIDI hub for a live show.

The GridLock II’s ability to rewrite its firmware while performing all the complex calculations within the unit is seriously impressive. It means the computer is relieved of almost all duties, and you can rely upon the kind of MIDI timing that, until now, has not been seen before. Having each instrument on its own well‑named port means less head‑scratching with routing and MIDI channels. It feels like someone has made you a custom MIDI interface for your studio. And as soon as you buy some new gear, it’s easily added with its own virtual MIDI port in your DAW (even the CV‑based instruments). It’s refreshing to spend more time making music and less dealing with the vagaries and whims of MIDI.

Conclusion

There’s a great deal of information, and misinformation, around timing, ‘groove’ and MIDI capabilities. People will tell you that under 10ms of lag or jitter doesn’t matter because the human ear can’t detect it, or that it’s natural ‘humanisation’. Poppycock.

Musicians (especially drummers) and studio engineers will tell you different. Sub‑millisecond timing can make a huge difference in ‘feel’. Imagine a kick drum and a tom, hitting at the same time. A few milliseconds in the trigger timing can mean the difference between two signals being in and out of phase, which can affect the mixed audio by removing critical bass frequencies and smearing transients. Now compound that problem across a whole drum kit, or even an entire studio.

The same is true with clocks and synchronisation. The more accurate the clock, the more reliable and predictable the results will be, with the ultimate prize being that everything sounds ‘in the pocket’. It is informative to understand how instruments can relate to each other in the time domain. To use MIDI to replicate how good players create ‘feel’ by naturally adjusting their timing, you need absolute control over timing to begin with.

Many will argue that MIDI is a serial protocol (meaning it cannot send two pieces of information simultaneously; they must be sequential), so bad timing is inherent in the system. Innerclock have taken every possible step to mitigate the timing issues that may arise as a result of this. Their custom Mac OS driver and a dedicated scheduler release events exactly on time using the GridLock’s own master clock. The result is sub‑10‑microsecond jitter and skew across all 44 ports, even under heavy load — a feat that no other MIDI interface can achieve.

I am seriously impressed by GridLock II. You don’t need to measure the timing to feel the results. It feels solid in the way that a good audio interface does. In fact, Innerclock are so confident in their engineering that they publish detailed specifications on their website, just as audio interface or mixer manufacturers might publish specifications for harmonic distortion, signal‑to‑noise ratio or dynamic range.

The GridLock II is perfect for medium to large‑sized studios. And also live rigs. It feels faster, more reliable, and more flexible than anything I’ve used before.

There is the occasional niggle, and a few signs that this is still a product in its formative stages. For example, in the Routing page of the Control application, you cannot filter by MIDI channel, which means that if you route a MIDI sequencer to a CV instrument, that CV instrument will respond to all MIDI channels. Innerclock tell me this should be easy enough to fix, so hopefully it will be sorted by the time you read this. The GridLock II Control application isn’t the prettiest thing in the world either, but that’s purely cosmetic. Also, using the MIDI clock time shift function can be time‑consuming because every time you adjust, you must save the firmware to hear the difference. It’s a shame that the shift functionality doesn’t work in real time, which would make it really easy to shift things by ear.

I cannot overstate the difference that good MIDI timing makes. Having several drum machines and synthesizers all locked perfectly into the groove is a revelation.

These are minor gripes, however. The GridLock II’s core functionality is seriously impressive. I cannot overstate the difference that good MIDI timing makes. Having several drum machines and synthesizers all locked perfectly into the groove is a revelation. You don’t necessarily hear it, but you feel it.

GridLock II is the most innovative MIDI interface on the market. At $2499, the price is significantly higher than any of the competition, but it’s not unreasonable. You get a ton of ports, near‑perfect timing, MIDI‑to‑CV, DIN‑Sync and genius DAW‑agnostic instrument‑based configuration. The GridLock II is a big step in the evolution of the MIDI interface, and it might just be the last MIDI interface you ever buy.