XEN FX LAB is a follow-up to a software hit (and hardware, before that), adding a modeled spring reverb, strike for “knocking” the virtual tank, and a dub button for adding dub-style throws, plus significant performance optimizations all round. And yeah, it’s time for more wild drones and dubs and echoes and the lot. macOS, Windows; VST3, AU, standalone; also on iOS.
I completely forgot that I did the original official walkthrough video for Zen Delay’s plug-in edition until one of the XEN FX LAB developers reminded me today. But here, for review:
The heart of the beast here remains the same: delay with six modes (now labeled more clearly, with tape, tape ping-pong, digital ping-pong, digital, and vintage), a virtual analog filter with resonance, and tube drive. And these sound great in software, though overdriving on the real hardware is always best.
Zen has become XEN (don’t ask). In addition to welcome performance optimizations (so it’s lighter on your CPU, as requested), this version has some nice new features.

There’s now a modeled SPRING REVERB. It has some unique parameters for controlling its sound, too — not only decay, but tension of the spring, too. Just as a real spring reverb tank would be, it’s added to the end of the signal — impacting both wet and dry. REGEN routes input back through the tank for spring feedback. That means you can produce ringing drones with this feature — including if you don’t want them, so be careful with the REGEN control and the signal you’re feeding in and its drive and feedback.
You can still adjust wet/dry and spring mix separately. The result is the ability to add rich layers of additional processing. And it is just impossible to overstate how powerful this is for drones, especially in various combinations with the existing drive and effects modes. See the video.
STRIKE knocks the tank — if you’ve ever slapped an amp, you know what this means. I found this of limited use, but with that tension control, well — someone will figure out something to do with it, I expect. Both STRIKE and DUB are MIDI-assignable, so you can play them live.
Just listen to how nicely this can drone — first play here. The synth is the very-nice AD-202 from Audio Damage, here just to do some quick-and-dirty synthesis.
DUB MODE is all about dub throws. With dub mode selected, the signal remains dry until you hit or hold DUB — then you get processing through the delay (and spring, if selected). When you release dub, the ringing echoes continue as you play input over top.
If you already longed for this feature, you know what I mean. But since it’s hard to word this vividly, here is a not-very-musical example just to clearly demonstrate what happens. And yes, this is very, very useful:
As before, there’s a powerful editing panel with modulation of cutoff and time, plus X AM and X FM features. See my original writeup. Now you just get all the extra icing on top of that (and the ability to do dub throws to whatever mayhem you patch up back there).

This update is bigger than it first appears. Adding the spring reverb with these controls makes this twice the effect it was. With the dub mode feature, there’s a layer of performative possibilities, too.
And given that the original Zen Delay plug-in was itself a software copy of the original hardware, it seems a safe bet to be on the lookout for some XEN FX LAB hardware, soon, too.
Available now on desktop. iOS version should be up soon, pending Apple approval (it isn’t yet as I write this).
I also love that feeding it no signal at all, it still decides to start droning (presumably from a tiny bit of noise out of the AD-202):