Review: Spitfire Audio Union Chapel Organ

The finet attempt to sample a pipe organ to date. Informed as much by love of the source instrument as by expertise in sampling.
Image placeholder title

British soundware developer Spitfire Audio has earned a reputat ion not only for meticulous attention to detail in sampling acoustic instruments, but also for maximizing the synthesis possibilities of Native Instruments’ Kontakt soft sampler and its scripting engine. Both of these philosophies are applied to Union Chapel Organ, a painstaking re-creation of a renowned and unique pipe organ. The result? A stellar virtual instrument for classical and liturgical organ repertoire that doubles as a tool for creating cinematic soundscapes.

The Actual Organ

Founded in 1799, Union Chapel is an active Congregational church, concert venue, and homeless outreach mission situated in London’s Islington neighborhood. Its pipe organ, designed by Henry Willis and completed in 1877, is considered one of the rarest and finest in the world. Notably, it’s one of two specimens in the United Kingdom that uses a traditional water-powered hydraulic blowing system. By modern standards it’s not enormous, with three manuals (choir, great, and swell in ascending order) plus a pedalboard, just over 2,000 pipes, and a relatively modest 37 stops. However, because its design is so well-matched to the acoustics of the room, it can sound a great deal larger than it is. The organ has been heard in a number of film scores, including 2001: A Space Odyssey and Koyaanisqatsi.

The UCO is a flutes-forward organ, but it can get more aggressive thanks to a handful of reed and string stops. These include a 16' contra gamba (bass viol) on the swell manual, 8' trumpet on the great manual, and a 16' ophicleide reed that adds a lot of bombast to the otherwise polite pedals. Since we don’t have room here for even the most basic introduction to pipe organs, I recommend visiting to learn what all the stops do. UCO’s stops are a tidy subset of what’s listed there.

The Virtual Organ

Spitfire sampled the UCO from four stereo mic positions, in retreating order of proximity: close, stage, ambient, and “outrigger.” These mic positions can be mixed with individual faders or via an “easy mix” macro that tracks the virtual listener’s location in the chapel.

For “straight” organ emulation, only a handful of Kontakt presets are needed—each manual, the pedals, and an All Manuals and Pedals patch. Within each of these presets are graphical organ stops that you click to turn on. In sampler terms, a combination of stops amounts to an articulation and corresponds to what organists call a registration. Key-switching of articulations is disabled by default, but you can activate it and thus employ an otherwise unused key group to change registrations the way piston buttons do on church organs. A swell control is mapped to the mod wheel (e.g., MIDI CC 1). To get fine-grained about shaping your sound, you can even set and save different mic mixes for each organ stop.

Fig. 1: Separate manuals arranged in Kontakt for multikeyboard playing. Setting up a multi-manual virtual pipe organ is straightforward: Call up the presets for the individual manuals and pedals into a Kontakt multi (see Figure 1). Set each to receive on a different MIDI channel. Stack some keyboards and a pedalboard and set each to transmit on a corresponding channel. (So you don’t run out of USB ports, it’s best to use a MIDI interface or for your main controller to be able to pass MIDI thru to USB.) I pulled this off using my Hammond XK-3C Pro system topped with an old Kurzweil K2000 as the third manual. For serious organ practice, companies such as Classic Organ Works (organ make controllers that duplicate the key size and feel of “tracker” organs in which the keys are mechanically linked to the pipes. UCO is every bit as serious a sound engine for serving organists with this level of dedication and would be an excellent choice for such a setup.

Image placeholder title

How does UCO handle coupling, the triggering of one manual by another? With the All Manuals and Pedals patch, which is more flexible than traditional couplers in that it lets you play any combination of stops from the entire organ from a single keyboard-slash-MIDI channel.

Sound Quality

Simply put, I can’t praise this highly enough. First of all, the organ in Union Chapel has a smooth and buttery sound. Even its more harmonically dense reed and mixture stops aren’t harsh or raspy, and Spitfire’s UCO captures that perfectly. Second, a pipe organ is a complex acoustic phenomenon that can’t be divorced from the room it inhabits, with sound sources firing different frequencies from multiple locations. A key aspect of the experience is all those sources blending “in the air” as opposed to “in some wires.” To create this illusion in a sample-based instrument is a gargantuan engineering task—which UCO performs with flying colors.

I couldn’t find any combination of stops and mic mixes that uncovered any undesirable sampling artifacts such as audible loop points, aliasing, or frequency dropouts due to phase cancellation. With all four mic sets active, though, I certainly could strain the throughput capacity of my late-model iMac, Core i7-and SSD-equipped though it may be. Though the demands are appreciably less than Spitfire’s Hans Zimmer Piano (reviewed May 2016), I still recommend hosting UCO on a striped RAID dedicated to samples, connected via Thunderbolt or SATA, for worry-free performance.


Fig. 2: The eDNA presets offer a world of synthesis beyond pipe organ emulation. Sporting an entirely different user interface, the eDNA presets showcase UCO’s double life as a synthesizer (see Figure 2). As with other Spitfire libraries that have this feature, the raw sample materials are the same. The basic idea is that you can morph and blend two sample sets, each of which has its own low-pass and high-pass filters as well as an ADSR envelope, tuning, and pan settings. “Wobbles” (basically LFOs) for the volume, pitch, and filter cutoff of each sample set add to the modulation options. In addition, separate glide (portamento) and “clone” (duplicate layers adjustable in semitones) sliders are available per set.

Image placeholder title

As with almost any parameter in Kontakt, you can automate the morphing itself and/or assign it to a MIDI controller in the Oscillate Mixer pane. You can apply effects, of course, but my favorite feature here is the Gate Sequencer. This is a dual row of gates, one for each sample set, with the number of steps variable from 1 to 32 including any odd length. Though step length is the same for both rows, you can toggle each step to block or pass sound for each row independently. Smooth-in (attack) and smooth-out (release) settings for each step make the gating more or less choppy. If you set up different rhythmic gating patterns for each sample set, morphing between the sets morphs between the patterns. In the middle, you’ll hear both patterns playing off each other.

One of the simplest things you might whip up here is the organ intro to Seal’s “Crazy,” but the possibilities get crazier, sharing an additive-synth quality owed to their pipe organ origins. Need unsettling dissonant drones because HAL won’t open the pod bay doors? Pulsating Philip Glass-iness? A sound for when Matthew McConaughey pilots his Lincoln through a black hole to find the Yellow King? This is how you do that.


On one hand, customers willing to pay close to $200 for “just” a pipe organ may have all self-selected already—and this group will surely be delighted. On the other, Union Chapel Organ’s sweet sound and non-intimidating number of stops make it a great entry point for anyone who’d like to discover pipe organ. Plus the eDNA section makes it not “just” an organ.

My only real criticism is that since it’s based on a single specimen, organists who want different configurations and historical instruments (including theater pipe organs) will need to look to software such as Hauptwerk. But where Hauptwerk emulates a broad range of organs well, Spitfire emulates one of the most revered “destination organs” in the world, flawlessly.

Snap Judgment

PROS Impeccable sound quality. Exhaustive sampling includes individual organ stops as well as separate manuals and pedals. Captures the provenance of a singular instrument. eDNA presets offer advanced sound design.

CONS Requires full version of Kontakt 5, not the free Kontakt Player. No full user manual in print or online yet.

Bottom Line

The finest attempt to sample a pipe organ to date, informed as much by love of the source instrument as by expertise in sampling.

£149 direct | about $200 U.S.