How swell and volume-swell technique changes what you need from reverb and delay

I spent the better part of a Tuesday evening in my studio — the spare room in my Bristol flat that my partner charitably calls "the noise cupboard" — trying to figure out why a reverb that sounded glorious with picked notes turned muddy and shapeless the moment I switched to swells. Same pedal, same settings, completely different result. That discrepancy sent me down a rabbit hole I haven't fully climbed out of since.

Volume swells are deceptively simple on the surface. You roll your guitar's volume knob up — or use a volume pedal — so the attack of the note is hidden and the sound blooms into being. That's it. But that absence of a transient is doing something quite specific to your reverb and delay pedals, and if you don't account for it when building your chain, you'll spend hours chasing a tone problem that's actually a technique problem in disguise.

What a transient actually does to your reverb

Reverb algorithms — whether spring, plate, hall or shimmer — generally behave differently depending on how they're fed. A picked note arrives with a sharp initial spike: high energy, fast, then decaying. The reverb grabs that spike and spreads it across time. The tail blooms out from a defined starting point.

A swelled note does the opposite. Energy builds gradually over the first half-second or more, depending on how slowly you roll up. There's no attack for the reverb to anchor to. Instead, the reverb is being continuously excited as the note grows, which means the tail and the note itself are reaching their peak almost simultaneously. On a reverb with a slow pre-delay setting — say, 0ms or close to it — the result is a kind of blurred, washed-together mass where you lose the sense of the note's shape entirely. Which can be beautiful, honestly. Or it can sound like you're playing inside a wet paper bag.

Pre-delay is the first knob to reconsider. For normal playing, short or zero pre-delay keeps things tight and immediate. For swells, I'd argue a longer pre-delay — somewhere in the 40–80ms range — actually gives the swell room to establish itself before the reverb engages. The note blooms, finds its pitch and volume, and then the reverb responds. That sequence matters. It's the difference between a halo and a smear.

If you're shopping for a reverb that handles this gracefully, the controls on something like the Walrus Audio Slö (check price) are well-suited to swell playing — the decay, mix and modulation interact in ways that reward slow attack. The best reverb pedals guide has a fuller breakdown of which algorithms cope best with ambient techniques.

Delay and the missing attack

Delay is where things get even more interesting. A delay pedal repeats what it hears. With a picked note, each repeat mirrors the attack of the original: you get a recognisable rhythmic pattern of transient-plus-decay, transient-plus-decay. With a swell, the delay is repeating a blob of growing-then-decaying energy. The first repeat sounds like a ghost of the swell. Fine. But the second and third repeats? They're copies of a copy, each one losing definition, often getting darker or woolier depending on the delay circuit.

That can be gorgeous — it's half the reason ambient players love analog delays. But it breaks down when the feedback is set too high or the delay time is too short. Short delay times with high feedback on swells create this dense, almost reverb-like smear that has no rhythmic identity and no sense of space. It just clogs.

For swell playing specifically, I tend to push delay times longer than I would for picked lines — often synced to a dotted quarter or longer — and I back the feedback off more than feels natural. The repeats should be supporting the swell, not competing with it. And the mix? I run it wetter than usual, because the swells themselves are already soft and atmospheric; a timid delay disappears.

The Strymon TimeLine (check price) has a filtering control per algorithm that lets you darken the repeats deliberately, which actually works beautifully for swell-based playing — each repeat naturally softer and warmer than the last, so the texture evolves rather than stacks. The best delay pedals guide covers the options at different price points if you're building a swell-capable chain from scratch.

Chain order: where the volume control lives changes everything

This is the part that took me the longest to sort out, and I'll admit I got it wrong for years.

If you're doing swells with your guitar's volume knob, the volume control comes before every pedal in your chain. The signal hitting your delay and reverb already has the swell baked in — no transient, gradual bloom. That's the most common setup and it works well.

If you use a volume pedal in your chain, placement matters enormously. Volume pedal before dirt and modulation, after reverb and delay? You're swelling the dry signal and the reverb/delay are responding to that swell in real time. Volume pedal after everything? You're swelling the entire wet mix — the reverb and delay are still reacting to a picked or played note, but you're fading their output up after the fact. That sounds completely different. The reverb gets a full transient to respond to, builds naturally, and then you reveal that already-rich tail by rolling the volume up. It's more lush in some ways, less "pure" in others. Neither is wrong. But you need to know which one you're doing and choose your reverb and delay settings accordingly.

Decay time and the silence between swells

One thing people underestimate: the gap between swells. If you're playing long, sustained blooms with space between them, your reverb's decay time shapes how much of the previous note bleeds into the next one. Set the decay too long and your swells start to pile up into an undifferentiated wash — which, again, can be the whole point, or can be a mess.

In performance, I actively use the decay time as a compositional tool. For sparse, meditative passages I want a long decay that hangs in the air. For something with more movement — where the swells are shorter and more frequent — I'll pull the decay back so each swell has room to exist on its own. If your reverb pedal doesn't have a decay knob accessible without diving into menus, that's a real limitation for live swell playing. It sounds like a minor thing until you're mid-set at the Stag and Hounds on Brunswick Road and you need to shift the mood on the fly.

Modulation inside the reverb tail

Many modern reverb pedals have a modulation parameter — a subtle chorus or vibrato applied to the reverb tail. On picked playing this adds warmth. On swells it can add something almost breathing, a slow pulse that moves with the fade-in of each note.

But if the modulation rate is too fast, or the depth too pronounced, the blooming quality of a swell turns queasy. The note is already moving dynamically in volume; add pitch movement on top and it gets seasick. I generally keep modulation depth conservative for swell-heavy playing — a little goes a long way, and slow rates (0.5Hz or below) are almost always more useful than faster ones.

Practical settings to start from

If you want a baseline to work from for swell-focused playing: set reverb pre-delay to 50–70ms, decay to medium-long (3–5 seconds depending on the room size you want), mix at 50–70%. For delay, try a dotted-eighth or quarter-note time, feedback at 20–35%, mix around 30–40%. Then adjust from there based on how fast your swells are and how much space you want between them.

The fundamental point is that swell technique isn't just a stylistic choice — it changes the input signal your effects receive in a way that requires different settings than standard picking does. Once you understand that, you stop fighting the pedals and start using them intentionally.

Anyway. I should probably go turn some knobs.