I studied astrophysics. You spend a lot of time around oscilloscopes when you do that — the hardware kind, with knobs that click and a CRT that won't quite stay calibrated. So when I got serious about making music and discovered s(M)exoscope, Bram and Sean's free audio oscilloscope plugin from Smartelectronix, something fell into place. Oh — I can see the signal again. I used it for years.

Then it stopped working. Modern macOS, modern DAWs — eventually s(M)exoscope just couldn't keep up. Armando Montanez later revived it for 64-bit and Apple Silicon — a lovely bit of stewardship, and the plugin that started all this for me still lives. But s(M)exoscope was always a free-running scope: modest resolution, no tempo sync. By then I was looking for something different.

So began the search.

What I tried

I tried Schulz.Audio's Oszillos Mega Scope, The Him's Sub Ninja, Blue Cat Audio's Oscilloscope Multi, Audija's Oscope, and approximately 25 others. They're all good work — every one of them gets something right that the others miss. But I never quite found the one I wanted to leave running on every track of every session. Either the display didn't scale cleanly to my screen, or the tempo sync wasn't there, or the CPU footprint added up across many instances, or the UI kept getting in the way of just looking at the waveform.

The plugin I did keep open, always, was Voxengo's Span. Free, clean, accurate — the spectrum analyser I'd trust without thinking. A year or two in, I bought Span+ because the upgrades were worth it and the free version had earned the upsell honestly. That model — give the community a free tool worth using, sell the version with the extras to people who want them — stuck with me.

So I built the oscilloscope plugins I wanted. Two of them.

SCOPE

A free oscilloscope plugin designed to leave running on all your key tracks and stereo output.

Scope is the free one. It's the plugin I wish I'd had the day s(M)exoscope stopped working.

VST3 and AU. macOS 13 or later, Intel and Apple Silicon native. No trial. No feature gates. No email harvesting. Free meaning free.

Twenty-two beat divisions from 1/128th note to 16 bars — straight, dotted, and triplet. Free-run mode for Hz and ms-based time windows when you don't want tempo lock. Polarity-aware clip detection on the border. Resize the window to any size up to 4K — the display stays sharp. Zero latency. Light enough to leave running on every track that matters.

Plugin

SCOPE

See the signal

DeltaScope

What Scope becomes when you need it to do more.

DeltaScope is the one I'd have happily paid Voxengo prices for, years ago. Same rendering engine as SCOPE, then keeps going.

It lets you compare any two signals. Drop it on two tracks and they find each other automatically by track name, or route a second signal in via sidechain — no bus routing. Five combine modes: overlay, stack, sum, delta, and sum+delta split. Delta mode subtracts the original from the processed signal so you can see — and optionally hear — exactly what your compressor took away, what your EQ reshaped, what your limiter caught.

It adds a spectrum analyser in the same window. Tilt compensation flattens the pink-noise slope so you read frequency balance instead of staring at a downward ramp. A seven-mode level meter — sample peak, RMS, true peak, crest factor, and LUFS momentary, short-term, and integrated — for delivery-spec readings without leaving the plugin.

It lets you measure directly on the waveform. Drag across a region and read frequency, MIDI note with cents deviation, peak/trough/RMS amplitude, and duration in ms or beats. Selection edges snap to zero crossings automatically. Sub-cent accuracy on sustained tones — the kind of detail you appreciate if you've ever spent late nights staring at a real oscilloscope screen trying to read a period off the grid.

Phase correlation mapped across time — not collapsed to a single needle — so you see exactly which moments cause problems. Band filters on main and sidechain to focus on the range you care about. Automatic delay compensation between tracks. Naked mode strips the UI for tutorials, livestreams, and video work.

Plugin

DELTASCOPE

See the difference

Why one engine, two plugins?

The free-oscilloscope-plugin landscape is mostly toys, trials, or "free this week only" promos. I wanted something I'd actually want to leave running — sharp, fast, accurate — and free meaning free. Scope is that, and it's a thank-you to the people whose work I learned from.

DeltaScope is for when you find yourself wanting to compare two signals, isolate a frequency band, measure a waveform, or just see things s(M)exoscope never let you see. Same display engine, same look, same feel — no relearning.

What's next

This was a soft launch. We haven't done any heavy promo yet. Rundown videos for both plugins are in production, going up on the YouTube channel and embedded here under Tutorials when they're ready.

Windows, AAX, and CLAP support are on the way. For now it's macOS — VST3 and AU, Intel and Apple Silicon native.

If you've already kicked the tyres on either one, I'd genuinely like to know what you think.