AudioScape XL-305R

We all love a good spring reverb, but this one offers a much wider range of sounds than most.

AudioScape’s outboard gear has graced our pages a few times now, but their XL‑305R stands out as a much more creative toy than most devices in their range, most of which tend to replicate things like vintage preamps, EQs and compressors. Housed in a 2U steel 19‑inch rackmounting chassis, it is a recreation of a vintage device, but this time it’s a stereo spring reverb unit. The resulting creation fits a whopping 12 springs inside, plus an EQ section, and it’s very different from your average guitar‑amp reverb, in a good way: it’s not overstating things to say that it’s capable of a huge range of effects, including a plate‑like smooth and dense reverb.

Mimicking MicMix?

Its muse is a pretty quirky device that was, reportedly, invented almost by accident: the MicMix XL‑305 Master Room Reverb, which was released in the USA in 1979, not long before affordable digital reverbs started to displace such mechanical gadgets in studios around the world. Now, I love a good spring reverb, and like to think I have a good grasp on what they can do for a sound. As well as those in my various guitar amps and Hammond organ, I’ve used vintage studio models including the AKG BX20 and the Great British Spring, along with more esoteric modern units such as IGS Audio’s wonderful four‑channel Springtime. But I’ve never actually laid hands or ears on an original XL‑305. I know it very much by reputation, though, and was particularly keen to hear what AudioScape’s interpretation might offer.

What really made the XL‑305 stand out from the crowd is that its spring assembly’s 12 individual springs were tuned to mimic musical intervals, and the result is a sort of musical sustaining effect — one that its designer suggests sounds rather like “opening the lid of a piano, holding the damper open and singing into the strings”. Furthermore, it’s a two‑channel device, in which, by design, the channels aren’t the same. Notably, the ‘odd’ delay times are placed in the left side channel, and the ‘even’ ones are on the right, so as to create a full stereo image even when fed a mono source. Those two outputs can also be summed to mono, to create a much denser mono reverb effect if desired. So, as I say, it’s a very different proposition from most spring reverbs’ more random wash of reflections.

Four units each house three springs, giving the XL305R a total of 12 strings that make possible its musical tuning.

AudioScape say they started by replicating the original device, but “reimagined the rest of the design from the ground up”, a process that involved four years of R&D, working with the designer of the original MicMix unit Wayne Kirkwood, and performing extensive listening tests before settling on their preferred spring decay times. It seems to me, then, that this isn’t simply a case of cloning old hardware for commercial reasons, but rather it’s a labour of love. That’s an impression that is underscored by the fact that these units, which are built by hand in small production runs, are rationed to a maximum of two per customer... and, crucially, by the sound as well.

Springing...