Iron Summing: the manual

Iron Summing is an analog-console summing system in one plugin. You insert it as a Channel on every track and switch one instance on your master to Bus. The instances find each other automatically and form one console: every window shows the whole group as live lanes, the Bus window mixes Channel trims remotely, and one All Saturation control on the Bus scales the colour of every track at once. Iron is engineer slang for transformer colour, and that is the sound modeled here: the transformer-coupled summing path of a large-format British console.

This manual covers installation and activation, setting up the console, both windows, session workflows, and the reference material for the v1.2 series, current through v1.2.1. It applies to the VST3, AU and AAX builds on Windows 10 and later and on macOS, Intel and Apple Silicon. v1.2 adds Flood, the glue compressor mirrored into an upward expander; it has its own section below.

Overview: the honest paragraph

Audio never flows between instances. Each Channel processes only its own track, and the Bus processes the real summed audio your DAW hands it. What the instances share is control data: meters, names, solo state, trims and the All Saturation scale, over a lock-free in-process registry. That is why Iron Summing runs at exactly zero samples of latency on every track, why nothing smears when your session has 100 instances, and why a Channel keeps working normally even if your host isolates plugins into separate processes: the group view then shows only what it can see, and says so.

The costs are measured, not estimated: 0.06 percent of one core per Channel and 0.38 percent for the Bus at 48 kHz with 512-sample blocks, so a 64-Channel session spends about 4.4 percent of one core on Iron. Every behavioral number in this manual, from the harmonic levels to the 3.0 dB glue cap, is held by an automated test suite before release.

Install and activate

Iron Summing is one product and one license: a single plugin binary with a Channel/Bus mode switch, installed as VST3, AU and AAX. Licensing runs through the license panel inside the plugin, and it is built so that an offline studio machine never needs an internet connection.

The machine code

Open the plugin's license panel and it shows a machine code in the form VTM1-XXXX-XXXX-XXXX-XXXX. Every activation, trial or full, is bound to this code.

Starting the 3 day trial

The trial is the full plugin for 3 days, both modes and every feature, no locks. To start one, go to /license/trial on the Vitric site, pick Iron Summing, paste the machine code from the license panel, then sign in with your email. A trial license file bound to that machine arrives at your verified address; load it and you are running. One trial per product, per person and machine. One license covers every instance on the machine, however many Channels the session runs.

When the trial ends, processing locks until a purchased license or valid subscription is installed. Saved session settings are preserved but not applied while locked. The plugin never requires a network connection and never refuses to load.

Full licenses, offline machines and moves

A purchased license key looks like VT-XXXXX-XXXXX-XXXXX-XXXXX and can be issued to 3 machines over its lifetime. Online machines activate from inside the plugin. Offline machines activate through the license portal at /license from any online device: enter the key and the offline machine's code, download the license file, carry it over and load it in the license panel. Deactivation is self service in the same portal, and lost keys can be resent to your registered email.

Setting up the console

Insert Iron Summing on every track you want in the console and leave those instances in Channel mode. Insert one more on your master and switch it to Bus with the mode switch. That is the whole setup: the instances find each other with zero configuration and every window shows the group as live lanes.

• Groups 1 to 8. The group chip assigns an instance to one of eight consoles, so a drum bus console and a mix bus console run side by side in one session. Two groups are fully isolated and tested.
• Names and colours. Lanes follow your DAW's track names and colours where the host reports them (Cubase, Nuendo, REAPER, Ableton Live). Labels are user editable everywhere: double-click a lane to rename it.
• Remote trims. Drag a lane's trim from the Bus window and the Channel's trim moves, gestured so your DAW's automation sees a normal parameter move.
• Solo. Session-level shared state across the group, like a monitor section button, and the room visibly darkens around the soloed lane. It is deliberately not automatable and not saved.

The Channel window

The compact per-track view: the group's lanes with this track highlighted, and the strip of controls that feed the iron.

• Tone, 0 to 100 percent. Transformer-style saturation as parallel harmonic injection: the direct path stays untouched, with zero phase shift at any setting. Even-order harmonics dominate at nominal level and odd-order arrives as you push. Low frequencies saturate first, because drive follows B equals V over f, exactly like a transformer core. At Tone 100, a -18 dBFS tone at 50 Hz measures its second harmonic near -55 dB and its third near -65 dB; the same level at 1 kHz measures below -100 dB. At Tone 0 the Channel is bit-transparent apart from your trim.
• Comp, 0 to 100 percent. Gentle 1.5 to 1 compression into the iron: fixed ratio, RMS detection, 30 ms attack, 120 ms release, and gain reduction can never exceed 6 dB. At 0 the stage is bypassed bit-exactly.
• Trim. Plus or minus 12 dB, also drivable remotely from the Bus window.
• The voicing. Every Channel is assigned one of 32 fixed console voicings: a drive bias, an even/odd blend, a core corner between 45 and 70 Hz and a character tilt of at most 0.25 dB inside the saturation path. The table is compiled into the plugin, so voicing 12 sounds identical on every machine, in every session, forever, and assignments save with your session.

The Bus window

The Bus processes the real summed audio the DAW delivers to the master. Its window carries the full lane view, the All Saturation control, the console EQ and the master row: Push with its Flood switch, Width, Space and Output, each dynamic module with its own power switch.

All Saturation

One knob, 0 to 200 percent, scaling the colour of every Channel in the group at once. It multiplies against each Channel's own Tone, so the balance you set per track is preserved while the whole console drives harder or cleaner. At 0 the saturation stage passes audio unchanged.

The console EQ

Four wide console curves: a low shelf at 45 Hz, proportional-Q bells at 550 Hz and 3 kHz, and an air shelf voiced at 22 kHz. Each band runs plus or minus 6 dB, and the curves are accurate to the documented targets within 0.3 dB at 44.1, 48, 96 and 192 kHz.

Push, the glue

Opto-style glue compression with a hard mathematical cap. The threshold is fixed; the knob drives the detector like a peak-reduction control. Gain reduction cannot exceed 3.0 dB on any material, because the curve approaches the cap asymptotically, so there is no wall. The attack is slow and program dependent, 60 ms nominal, so the front of a hit passes before the glue leans in: measured 10 ms into a burst, the gain reduction is 5 percent of its settled value. The release is fast and program dependent: 90 percent recovered 300 ms after a burst ends. A small transient enhancement of at most 1.2 dB restores attack edges; measured, the first 5 ms of a hit leaves the plugin at full level or louder. At 0 the stage is bypassed exactly.

Flood, the glue mirrored

New in v1.2. The switch above the Push knob flips the glue into an upward expander: same detector, same threshold, same taper, same ballistics, mirrored. Loud passages bloom upward instead of being glued down, the boost cannot exceed 3.0 dB on any material (measured 2.999 dB worst case), and the lift mirrors the cut to 0.01 dB. Flipping the switch while audio runs is click free: the direction glides through zero in about a tenth of a second. Factory presets always recall with Flood off.

Width

Mid/side depth ahead of the harmonic stage. The mid channel is never processed and side content below 130 Hz is never widened, so your low end stays mono. Above 130 Hz, four expander bands split at 550 Hz, 2 kHz and 8 kHz add at most 2 dB each, RMS detected at a 2 to 1 expansion ratio, over a static side gain that never exceeds 130 percent. Each band's threshold follows the material's own long-term level, so the effect self-calibrates at any gain staging. The dedicated on/off switch gives an exact bypass for mono-compatibility checks.

Space

Split-band harmonic generation on the sum: even-order products from content below 500 Hz, odd-order products from content above 1 kHz, and sources in the 500 Hz to 1 kHz window produce nothing above a -95 dB floor, measured at 550, 700 and 850 Hz at full knob. The amounts are seeded per instance, stored in your session and identical on recall.

Module power and metering

EQ, Push, Width and Space each have their own power switch. Bypassing a module is click free and nulls exactly once its smoother settles. The metering is honest: a real stereo correlation coefficient from -1 to +1, the summed level arriving at the Bus before the master section, and a 0 to -120 dB output meter. The Bus output control trims plus or minus 12 dB.

Presets

Nine Bus presets named for jobs, setting Bus parameters only, so your per-Channel work is never touched by a preset. Presets recall with every module powered on and Flood off. The Clean Console Off preset is a null-test reference: load it and the Bus passes audio unchanged, and we invite the test.

Workflows

The whole mix

Channels across the session, one Bus on the master. Set per-track Tone where each source wants it, then ride All Saturation from the Bus to scale the whole console's colour at once: the mix keeps its internal balance while the iron drives harder. A 64-track console costs about 4.4 percent of one core, and zero latency everywhere means the DAW never engages delay compensation for it.

Drum bus

Give the kit its own console on a second group: Channels on the drum tracks, a Bus on the drum bus, group 2 on every instance. Push leans into the kit with the 3.0 dB cap keeping it honest, and because the attack is slow and program dependent, the front of each hit passes before the glue arrives. Space adds low even-order weight under the kick without touching the mids.

Choruses that lift

Flood on the loudest section turns the glue inside out: the same detector and ballistics, mirrored upward, so the chorus blooms up to 3.0 dB without a fader ride. The flip is click free while audio runs, so it can be performed at the transition.

Stems and print chains

Zero real latency and bit-transparency at Tone 0 mean Iron can live on every stem of a print chain without smear. Nothing is random between recalls: every per-instance variation, from console voicings to Space seeding, is stored with the session, so a mix reopened next year nulls against itself, bit for bit.

Reference

What it does not do

These are design decisions, and each is also a fact:

• No latency, ever. No oversampling, no lookahead, no linear-phase filters. Zero samples in both modes at all sample rates. Aliasing is controlled by design instead: products measure below -80 dB at 44.1 kHz at full drive, because the saturators are low order and drive-weighted toward low frequencies where products stay in band.
• No noise generator. Modern console noise floors measure below -80 dBu and add nothing we can defend, so we left it out.
• No crosstalk modeling. Real crosstalk is between channels; a plugin that fakes it inside one track is not modeling a console.
• Nothing random between recalls. All character variation is seeded and stored. A mix reopened next year nulls against itself.

FAQ

Does audio flow between the instances? No, and that is deliberate. Each Channel processes its own track and the Bus processes the real summed audio the DAW delivers to it. Instances share only control data: meters, names, solo, trims and the All Saturation scale. That is why every track has exactly zero samples of latency and why nothing smears at 100 instances.

What makes the saturation transformer-style? The drive law. Low frequencies saturate first because drive follows B equals V over f, the way flux builds in a core. The harmonics are measured: at Tone 100, a -18 dBFS tone at 50 Hz shows its second harmonic near -55 dB while the same level at 1 kHz measures below -100 dB. The injection is parallel, so the direct path carries zero phase shift at any setting.

Can the glue ever overcompress? No. Push approaches 3.0 dB of gain reduction asymptotically and can never exceed it, on any material. The attack is slow and program dependent, the release fast, and the first 5 ms of a hit leaves the plugin at full level or louder. Flood applies the identical contract upward: the lift mirrors the cut to 0.01 dB.

Will my mix recall identically? Yes, bit for bit. Every per-instance variation, from console voicings to Space seeding, is stored with the session. There is no random component between recalls, and at Tone 0 the Channel is bit-transparent. The Clean Console Off preset exists as a null-test reference.

What does a big session cost? Measured at 48 kHz with 512-sample blocks: 0.06 percent of one core per Channel and 0.38 percent for the Bus. A 64-Channel session spends about 4.4 percent of one core. Zero latency everywhere means no delay compensation anywhere.

Why is solo not automatable? Solo is session-level shared state across the group, like a monitor section button: it exists to audition, not to mix. It is deliberately not a parameter, not saved and not automatable.

My host runs plugins in separate processes. Does the console break? No. A Channel keeps processing its own track normally. The group view can only show the instances in its own process, and it says so instead of pretending.

Do I need a license per instance? No. One product, one license, however many Channels the session runs. The license can be issued to 3 machines. Contact support for a legitimate hardware replacement after that.

What DAWs does it support? VST3, AU and AAX on Windows 10+ and macOS covers Pro Tools, Logic Pro, Ableton Live, Cubase, Studio One, FL Studio, REAPER and every other major host. Lane names and colours follow the DAW where the host reports them, and labels are editable everywhere.

Can I try it before buying? Yes. Every Vitric plugin has a free 3 day full-function trial, requested at /license/trial with the machine code from the license panel. One trial per product, per person and machine.

Support

Questions, activation trouble, or anything this manual does not cover: support@vitricaudio.com. Every purchase also carries a 14 day money back guarantee, no questions asked, so the real test is always your own sessions.