Flock Audio Patch VT & Patch App DX

The slick and very useful iPad version of Patch App DX.

Flock Audio’s software‑controlled routing system goes from strength to strength!

Flock Audio’s Patch analogue routing matrix range has expanded somewhat since Matt Houghton reviewed the original 32x32 Patch and Patch App control software back in SOS April 2021. That year also saw the release of the smaller 16x16 Patch LT, the flagship 96x96 Patch XT, and version 2 of Patch App. In 2022, Flock launched Patch App v3 and, in December of that year, Patch App DX. Then, last Summer, the 64x64 Patch VT was announced, followed earlier this year by an updated Patch App DX v1.1, which brought iPad and iPhone compatibility to the main macOS and Windows program. So we decided it was time to catch up with what’s on offer, and Flock kindly sent me a Patch VT to test, along with a licence for Patch App DX 1.1.

Patch VT

The core functionality of the Patch VT hardware is, essentially, the same as that of the original Patch, so I don’t propose to discuss the hardware much here, other than where it differs from the original Patch — if you need more detail on that side of things, you can find plenty in Matt’s original review and on the Flock Audio website.

Obviously, the Patch VT is rather larger than the original Patch. Its substantial 3U chassis is necessary to accommodate the 16 rear‑mounted, Tascam‑format D‑Sub connectors that carry its 64 balanced, line‑level analogue audio inputs and 64 corresponding outputs. These are mounted vertically on the rear panel, which also sports a USB port for connection to a computer and a combined mains switch and IEC power inlet.

The front panel features a striking, incised letter ‘V’ and there’s a recessed area containing a pair of balanced XLR/TRS I/O connectors — these can optionally be routed to the first two rear‑panel channels to enable ad‑hoc connections. Power on/off is controlled by a large, non‑latching button with a blue LED‑illuminated outer perimeter, whose various solid/fade/flash modes indicate power on, standby mode (the Patch VT has an adjustable sleep/wake function, inherited from the Patch XT), computer connection status, and a system error or hardware fault.

The 3U rackmount Patch VT: built on the same principles as the original Patch, but with twice the I/O.

Patch App DX

Unlocking the full functionality of Patch VT’s multi‑patented, crosspoint‑switched analogue routing matrix requires the new Patch App DX control software. This is a premium upgrade and expansion of the current Patch App. To their credit, Flock Audio say they intend to keep the main app free and updated on an ongoing basis, but Patch App DX requires a paid (perpetual or subscription‑based) licence that authorises a group of applications for different operating systems: Patch App DX for macOS (10.13 or newer) and Windows (10 and above); Patch App DX for iPad (iPadOS 14 and above); Patch App DX Remote for iPhone (iOS 15.6 and above); and DX Bridge, an AAX/VST/AU plug‑in that not only enables routings stored in the desktop Patch App DX to be recalled from within the DAW, but also allows you to store and recall those routings within a session. iPad and iPhone apps connected to the same wireless network as the desktop computer will automatically connect and sync with Patch App DX. I suspect the idea is that a studio that invests in a Patch system will have the main app on the studio’s computer(s) and that engineers who go to work in that studio can access the app on their own devices.

The iPhone version of Patch App DX can be used to create and tweak routings offline.The basic structure of Patch App DX’s GUI remains the same as that of its ancestor, the differences largely being the additional controls required for the new app’s increased functionality. In the Patch VT environment, the horizontally scrollable grid that fills most of the screen contains 64 vertical Paths, of which eight can be displayed at any one time. The cells in this grid display the contents of the active, user‑defined signal flows.

Patch App DX contains two new path‑related features. First, a Mute All control mutes all paths, so you can unmute and remute paths individually or in combinations, much as you would with tracks in your DAW software. Second, Drag Navigation allows you to scroll horizontally through paths by selecting an inactive unit from the Hardware Index on the left of the screen and dragging it to hover over either edge of the Path grid. A small thing, perhaps, but a helpful improvement.

The Hardware Index, sitting on the left of the screen, is where you can set up and store output connections from your collection of analogue hardware, DI boxes and microphones in so‑called “digital rack spaces”. The number of connections obviously depends on the Flock device(s) you own, but with a Patch VT you see 64 inputs and 64 outputs.

The Index’s setup menu is arranged in two vertical columns of colour‑codable input and output ‘rack spaces’. Connected hardware can now be labelled, colour‑coded and configured either in mono, linked stereo (which takes up one space) or unlinked as separate L‑R or multi‑channel I/O (occupying two or more spaces). Unlinked L‑R inputs and outputs can be paired to allow for stereo control. If a unit in the Hardware Index has been set up to allow phantom powering, Patch VT will automatically deliver 48V when that unit’s output is routed to the first slot in a path.

Another new, colour‑codable option allows you to group hardware together in Folders, which sit at the top of the Hardware Index for easy access. A new navigation feature in the Hardware Index enables the creation (and colour‑coding) of shorthand text tags — for example comp, eq, distort, convert — that, when selected, display hardware with those letter sequences in their name. If your path count exceeds the on‑screen display limit, a new Find Me function (activated by a right‑click on an already assigned rack space) will immediately bring up the path containing the active hardware.

Routing in Patch App DX is now a simple drag‑and‑drop process from index to Path cell, or cell to cell. Personally, I often found selection from the older drop‑down menu option (right‑click on a cell to display) to be more convenient when selecting a replacement for the contents of a cell. Creating mults (two or more signal paths that start with the same unit) is a one‑click process that is completely devoid of the impedance issues that can arise in a physical patchbay.

The Routing menu, positioned at the top right of the GUI, allows you to store, recall, edit, delete, import and export the routings that you create. An associated undo/redo icon not only eases editing, but also can act as a quick‑and‑dirty A/B comparison tool. A slightly left‑of‑centre ‘Toggle and Control’ line‑up (which also encompasses the Clear All and bank switching controls) allows you to route the front‑panel inputs and/or outputs to the first pair of rear‑panel I/O. Another new feature allows the muting of all paths, and the use of the mute indicator icons to mute and re‑mute paths, to quickly check individual paths and multiple path interactions. Also new in Patch App DX is the Quick Strip on the bottom right of the GUI, in which you can store six of your most‑used routings for speedy, one‑button recall.

Patch App DX makes it easy to capture photos to record hardware settings, mic setups and so on.

Underneath this Toggle and Control centre sits arguably the most practically important of Patch App DX’s new features: Hardware Management. Here, you can store, catalogue and annotate photographs of microphone, stand and screen positioning (Tracking Recalls) and hardware front‑panel settings (Hardware Recalls), on a routing‑by‑routing basis. A third section, Session Notes, allows you to add and store any notes on the session. When you recall a routing, an indicator in each of these sections will illuminate if anything is stored in them.

Even at higher than usual monitoring levels, I was unable to detect any noise in, or any other effect on, the audio passing through.

In Use

Sonically, the Patch VT hardware appeared to me to be completely transparent. Even at higher than usual monitoring levels, I was unable to detect any noise or any other effect on the audio passing through a four‑unit stereo path, in which the connected hardware was routed but hard‑bypassed internally. Given the unit’s specified ‑93dBu noise floor (A‑weighted), flat audio frequency response, 127dB dynamic range and 0.0015% THD, this was hardly surprising. Nor did I notice any obvious change in level over the length of that signal chain.

As the Patch VT runs at +4dBu line level, microphones and any low‑output hardware will require a boost from a preamplifier to achieve optimal results. Flock Audio addressed this requirement themselves recently, by releasing the eight‑channel CX adjustable booster/preamplifier. My only concern with the Patch VT operationally is the amount of heat generated by its output cards, since this activates its internal fan occasionally, even in free space at normal ‘room temperature’ here in the UK.

Patch App DX is an impressive, superbly conceived program that offers comprehensive and intuitive control of Patch VT’s range of functions, with DX Bridge providing the necessary link to your DAW. The iPad app could be really useful — it adds the convenience of touchscreen remote control and offline routing and hardware programming. The iPhone app obviously has a smaller interface, and while it does allow you to recall all stored routings, I suspect that its primary use may well become the taking and uploading of photographs for the tracking and hardware recalls.

There’s plenty more to explore in the operational relationship between Patch VT and Patch App DX, with lots of detailed settings that can be tweaked, and handy features such as an eight‑channel Audio Present indicator that can be accessed through the Settings menu. There’s little point me simply regurgitating what you can find easily in the product manuals, though, so if you’d like more granular detail I’d advise heading over to the Flock Audio website. Still, hopefully this overview has given you a good feel for what this combination of hardware and software can do.

The software provides a host of useful features, including a DAW‑style Mute All command, and an eight‑channel signal present indicator.

Verdict

While Flock’s hardware is not without strong competition (see the ‘Alternatives’ box), when it comes to the software side of things they’re unrivalled: the Patch VT/Patch App DX ecosystem is the most comprehensive, intuitive and powerful approach to the integration of analogue signal routing in a hybrid workflow that I’ve come across to date. I could certainly make great use of it, though its price means that purchases will probably be limited to commercial studios and private individuals who have both the hardware inventory and the financial incentive to justify the investment required.