Hold a chord in most synths and nothing happens. It just sits there. So you spend twenty minutes drawing MIDI by hand to get one bar of movement, and half the time it still sounds stiff.
The serum 2 arpeggiator fixes most of that. It’s not the usual up-down-random toy. It’s closer to a step sequencer bolted onto the synth, with per-step control over note, length and velocity. You can sketch a full melodic line without ever touching your DAW’s piano roll.
We at Monosounds have been building Serum preset packs since 2022, and since Serum 2 shipped in March 2025, the arp is where I spend a stupid amount of my patch-design time. Here’s what I’ve learned, with real settings you can copy.
One Panel, Two Personalities
Serum 2 ships with a built-in arpeggiator and sequencer, something Serum 1 never had. And since the upgrade is free for Serum 1 owners, there’s no excuse to be on the old version.
The panel does two jobs. In arp mode it takes the notes you hold and cycles through them: up, down, the usual direction options. In sequencer mode it plays a pattern you program step by step, and each step carries its own settings.
Everything syncs to host tempo. Set the rate to 1/16 at 126 BPM and every step lands exactly on the grid. That’s the whole appeal: tight timing with zero MIDI editing.
If you’re still finding your way around the new tabs, our Serum 2 shortcuts and hidden features post covers the workflow stuff I wish I’d known in week one.
Per-Step Control in the Serum 2 Arpeggiator
This is where the serum 2 arpeggiator stops being a preset gimmick. Every step in the pattern gives you independent control over four things:
- Note – transpose each step in semitones. Step 1 plays the held note, step 3 plays +7, step 5 plays +12. You’re writing melodies inside the synth.
- Length – how long the step sounds before it releases. Short steps give you plucky gaps. Long steps run into the next one.
- Velocity – per-step level. This is the groove control most people skip, and it’s the most important one.
- Direction – how the pattern walks through your held notes: up, down and the variations between.
Velocity earns a special mention because it doubles as a modulation source. Route velocity to filter cutoff in the mod matrix and quiet steps go darker while accented steps snap open. One routing, instant depth. If the mod matrix still feels like a spreadsheet to you, our Serum 2 modulation guide walks through it slowly.
My default starting point: 8 steps at 1/16, full velocity on steps 1 and 5, everything else around 70 percent. That alone makes a static pattern breathe.
Using It as a Step Sequencer
Here’s the mental switch: stop holding chords and hold one note.
With a single held C and per-step note offsets, the pattern becomes the melody. Try 0, +3, +7, +12, +10, +7, +3, 0 at 1/16. That’s a full minor arpeggio line, and you programmed it in fifteen seconds. Change the held note and the whole line transposes. That’s faster than any piano roll edit.
This is how I build rolling basslines for techno packs. One held note, steps 0, 0, +12, 0, gate around 50 percent, velocity accents on the off-steps. The +12 pops out over the kick and the short gate keeps the low end from smearing.
Some starting points by use case:
| Use case | Rate | Step length | What matters most |
|---|---|---|---|
| Rolling techno bass | 1/16 | ~50% | One held note, +12 pops, short gate |
| Trance pluck line | 1/16 | 60-70% | Up mode, 2 octaves, velocity accents |
| Melodic techno lead | 1/8 | 70-80% | Per-step notes, minor scale offsets |
| Tech house stab | 1/16 | ~40% | Velocity to cutoff, sparse steps |
| Ambient texture | 1/4 or 1/2 | 90-100% | Granular engine, slow evolving steps |
The melodic techno row is basically the recipe behind half the leads in our packs – there’s a longer breakdown in our melodic techno in Serum 2 article. And if tech house is your lane, the stab settings above pair well with the patches in our tech house presets roundup.
Turn a Boring Chord Into a Moving Line
This is the five-minute exercise I give anyone who says their pads sound lifeless.
Take any pluck or pad patch. Hold an A minor chord. Turn the arp on, rate 1/16, direction up, range 2 octaves. Already better. Now cut the step length to around 50 percent so there’s air between the notes.
Then the part everyone skips: velocity. Drop every even step to about 60 percent and leave 1, 5, 9 and 13 at full. The accents now lock to the kick and the line grooves instead of machine-gunning.
Last move: route velocity to filter cutoff, medium amount. Quiet steps go dull, loud steps go bright. The chord you held hasn’t changed – but it’s a moving, breathing line now.
If you’d rather study finished examples, our free Serum 2 arpeggio presets are built exactly this way. Load one, open the arp panel and see which steps are doing the work.
Arp Plus Granular: Rhythmic Textures
My favorite Serum 2 combo right now: the serum 2 arpeggiator driving the granular oscillator engine.
Granular sounds are usually washy and shapeless. The arp gives them a pulse. Every step retriggers the grain cloud, so an evolving texture suddenly has rhythm without losing its texture-ness.
The recipe: switch an oscillator to Granular, drop in any sustained sample – a vocal phrase, a string note, a field recording. Set the arp to 1/4 or 1/8, step length near full so grains bleed between steps. Then use per-step velocity to modulate grain position through the mod matrix, so each step reads a different slice of the sample.
One warning: granular can eat CPU. Serum 2 supports up to 256 grains, but you almost never need that. Keep the grain count low – 8 to 16 does the job for rhythmic work – and drop unison to 3 or so if the patch chokes.
A few of the atmosphere patches in our free 250+ Serum 2 presets pack use exactly this trick. They’re free and royalty-free, so pull them apart and steal the routing.
Getting Ideas Out of the Synth
The arp pattern lives inside the patch, which is great until you want to edit the line as notes. Two ways I handle it.
First: rebuild it in the piano roll. Sounds tedious, but it isn’t – the step grid already tells you every note and length, so it’s a two-minute copy job. Do this for keepers, because piano roll MIDI is easier to arrange, humanize and hand off.
Second: go the other direction. Start from existing MIDI, drop it on a track, and run Serum 2’s arp over the sustained chords. This is where MIDI packs earn their keep as raw material – our Hidden Gems artist-inspired MIDI pack is full of chord progressions that turn into completely different lines once the arp chops them up. Same chords, ten different results, depending on your step settings.
Serum 2 Arpeggiator FAQ
Does Serum 2 have a built-in arpeggiator?
Yes. The arpeggiator and step sequencer are built into Serum 2, which launched in March 2025. Serum 1 never had one – you needed your DAW’s arp or a separate MIDI plugin. And since Serum 2 is a free upgrade for Serum 1 owners, this feature costs you nothing.
Can the Serum 2 arpeggiator work as a step sequencer?
Yes, and honestly that’s the better way to think about it. Hold one note, program per-step pitch offsets, and the pattern becomes the melody. Per-step length and velocity give you gate and groove control that a classic arp can’t touch.
Does the arp add CPU load?
The arp itself is nearly free. What costs you is the patch it’s triggering – fast 1/16 retriggers on a 16-voice unison patch with granular running will hurt. Drop unison to 3-7, cap the polyphony, and keep oversampling at 2x. If a texture patch still struggles, freeze the track and move on.
Do Serum 1 presets work with the new arp?
Serum 1 presets load fine in Serum 2, but they were made before the arp existed, so it’ll be off by default. That’s actually an opportunity: load an old pluck preset, switch the arp on with the settings from the table above, and you’ve got a new patch in thirty seconds.
Where to Go From Here
The short version: program velocity before anything else, keep gates around 50 percent, and treat the serum 2 arpeggiator as a sequencer, not a chord toy. Those three habits cover most of what makes an arp line sound intentional.
If you want a shortcut, grab our free 250+ Serum 2 presets – no strings attached. Plenty of them have the arp doing the heavy lifting, so open the panel, look at the steps, and take what works.
I run Monosounds.studio and make the packs myself. Ten-plus years of producing, 97+ releases, 16,000+ downloads. Every Serum 2 preset we ship passes a CPU check on a mid-range laptop and gets used in a real track before release. If it does not survive a mix, it does not go in the pack.
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