Tiptop's veteran effects module has an ace up its sleeve.
Meanwhile, a new type of customer was emerging. As modular fever grew, producers used to computers, presets and recall started demanding the same of a format whose origins were staunchly opposed to such conveniences. While it's true that opening the Pandora's Box of digital processing led Eurorack away from its roots, some amazing digital effects modules were being released. Make Noise and Tom Erbe's Erbeverb is ubiquitous to the point of over-saturation, while Intellijel's Rainmaker is arguably the most disturbingly powerful delay released to date.
So where does this leave the Z-DSP? So much has changed since its original release. Tiptop recently rolled out a newly-updated version, which begs the question of whether it has the legs to keep up with its new competitors. Superficially, the NS upgrade isn't a huge overhaul either. Besides a brighter, more colourful front panel, there's increased headroom and better sound quality. You can drive the new Z-DSP much harder than the original with far less noise. The analogue feedback circuits are easier to keep under control, offering a more musical take on decaying effects tails. Plus, there's an equal-power crossfader on the Mix control, which means there are no big volume dips as you build up the wet amount. There's also a new set of effects cards, which you insert into the module to load a set of eight algorithms. Owners of the original Z-DSP know that these improvements are big wins, but the blood and guts of the module remain more or less unchanged.
That's a good thing. For years, the Z-DSP was the final word in crisp, multi-dimensional effects, and the enhanced internal circuitry has taken it up a few notches. It's hard not to be impressed by its crystal clear, high definition reverbs and delays, which are often grandiose and occasionally awe-inspiring. No matter what effects card you're using, adding just a hint to a dry oscillator makes a huge difference to the presence, vitality and stereo spread of the sound. There's also something to be said for flanking digital processing with two analogue stages. Where software effects can sometimes sound a little sterile, the Z-DSP produces a very rounded, vivid tone that makes even huge reverbs sound more like real spaces. As such, the Z-DSP shouldn't be discounted for general use in production. Whenever I needed a long reverb, basic to complex delays or Karplus-Strong style effects, I'd always take the Z-DSP's results over my usual plug-ins, which I wasn't exactly unhappy with beforehand.
This utility is expanded exponentially by the Z-DSP's open feedback networks. While it's not unusual to have open feedback paths on Eurorack delay modules, the Z-DSP gives you a stereo pair with their own VCAs. The applications are titillating to say the least. Imagine you've got the left side of a delay tail. Maybe you've routed it through a filter, some other effects, a ring modulator or whatnot. Route a sequence, for instance a multiplication of the original clock, to an envelope, send it to the Z-DSP's feedback VCA and you have dynamic, rhythmic control over the volume of your feedback path. You could have a simple 16th note sequence where, say, every third note lets in whatever's happening in the feedback path. Sure, you can achieve this with a dedicated VCA, but Tiptop building it into the module itself implants this type of patching into how you think about using the module.
Nevertheless, a recurring retort levelled at the Z-DSP—or any digital effects module for the matter—is, "Why would I spend €429 on a module when I could run similar effects on a computer?" While this line of thinking looks past a multitude of factors, not least voltage control, programme switching and an open coding environment for developers, the Z-DSP has a big trick up its sleeve: you can modulate the clock.
This doesn't mean "clock" in the rhythmic sense of the word. We're talking about the speed at which the Z-DSP processes sound. The terminology might sound a little abstruse, but clock modulation turns the Z-DSP from a great module into an exceptional one. I can't emphasise enough how important this feature is. You could very happily use the module without it, and there are plenty of users out there who love the Z-DSP without touching the clock. But messing with it led to sounds that I've literally never heard before. We could dedicate a whole review purely to a discussion of clock modulation because it makes the Z-DSP a whole other instrument and a fascinating one at that.
Messing with the clock is often unpredictable, but it can take you places you otherwise couldn't get to. To be effective, you need to modulate it with very high clock speeds, preferably with a high-range oscillator—it's worth reiterating this point as plugging in a regular CV source makes the program crash because it slows the processing speed to a snail's pace. Subtle shifts to the frequency of the modulator knock the Z-DSP around like a ragdoll, passing from minor colouration to a sludgy, bit-crushed mess. Modulating the clock also has an odd trickle down effect on the other parameters. It's hard to know exactly what the relationship is, but on some algorithms, altering the clock speed causes the other parameters to lag and then attempt to catch up, generating all sorts of strange, and often rather musical, aliasing. You might be sitting at a patch that sounds mostly like garbled digital noise, only to slightly change the behaviour of the modulator and have a huge expanse of gorgeous, complex effects appear out of nowhere. It's crazy how fine the line is between a mess and pure beauty, but that's part of what makes it so fun. To be fair, it's all too easy to cloak these bizarre sounds in a cloud of wriggling digital artefacts, but bringing down the clock speed ever so slightly produces a pleasing '70s-era lo-fi gloss that's highly useable in a production context.
With clock modulation, the Halls Of Valhalla card acquires a frankly beautiful screen of hiss that had me thinking equally of Basic Channel and Actress. The clock speed seems to change the pitch of the entire signal. Sometimes I was confused as higher clock speeds would end up in silence. Then it would cross some hidden threshold and blast into life with a dramatic explosion that'd either settle into smooth serenity or a yawning drone depending on God-knows-what. Gently shaping the fine tuning of the modulator made me think of the Eventide Space's more extreme algorithms, where the shimmer pitch shifts in long warbling waves. Other times the high frequencies are filled by what sounds like a swarm of self-oscillating filters being wrenched by LFOs. On another patch, the reverb tails created down-shifting shadows of the input that dropped in pitch as they decayed—don't ask me how or why.
The new Spirals card is ostensibly built for pitch-shifting multi-tap delays, but abusing the clock brings it into evolving reverb territory. Removing the clock modulation has the jarring effect of being pulled out of a dream, as trails of open space are suddenly wrenched into tight, rhythmic delays. Take the Pitch Pong algorithm. With the clock left alone, it's a fairly straight ahead ping-pong delay with pitch modulation. Hit the clock input and each side of the stereo field acquires a mind of its own, moving at different speeds with different modulations, sounding something like four delays tangled together. Panning Detune Taps gets us back into quasi-reverb territory, creating chorused drones that had me forgetting what the input source even was. Clock modulation aside, Spirals tends to thrive on faster rhythmic material, particularly 16th note patterns. Interval Feedback in particular can create charming physical modelling-esque ghost notes to follow your sequence.
Speaking of the new cards, if I had to pick one, it'd be Mariana Trench. The FDN Waveguide algorithm was a favourite, largely for its angular, comb filter style sounds. But with the right clock setting, it turned into a delay that sounded like someone falling down the stairs in a 1930s film. Carefully opening the Damp control turned it into an avalanche heard from an underground bunker.
I could reel off evocative similes for clock modulating just about any of the programs on any of the cards, such are the fathomless depths of variety on offer. Combine this with the pristine quality of the algorithms, the pair of open feedback paths, the in-built VCAs and overall CV control and you have a deadly serious effects processor, be it modular or otherwise. Despite being based on a design that's almost a decade old, the updated Z-DSP can be genuinely thrilling.
Ease of use: 4.5