RSL Bastion Available now

Two compressors. One chassis. The last stage before it leaves the room.

A vari-mu stage that levels program material the way a needle reads it, and a discrete VCA stage that catches the peaks it leaves behind. Run them in either order, see which one is doing the work, and hear exactly what each is taking.

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$69, regular price $99. Available now.

Installed and activated through RSL Hub on up to 4 computers, with no license key to enter.

AU, VST3, AAX, Standalone on macOS 11 or later; VST3, Standalone on Windows 10 or later (64-bit)

RSL Bastion controls dynamics; it is not a color box. For harmonic density put the Dual Core Saturator in front of it, and set the compression afterwards.

The RSL Bastion interface: the VCA stage, the dual gain reduction meters and the vari-mu stage with its tubes lit. — The panel reads left to right as the signal does: input, the first stage, the meters both stages report to, the second stage, output.

Two stages, opposite on purpose

Stage — Vari-Mu

Program compression

The musical stage. It reads level rather than peaks, its curve has no corner, and it never audibly grabs: the reduction settles instead of clamping. It is what makes a mix feel dense and cohesive rather than held down.

COMPRESSION is drive, not a threshold. It pushes harder into a fixed cell and takes the same amount back out, so turning it up makes the stage work harder, not louder. The tubes distort more the harder it is working, and HARMONICS decides how much of that you keep.

Stage — VCA

Peak compression

The precision stage. Rectifier detection, ballistics on the gain, and the ratio, knee, attack and release you chose — nothing program-dependent unless you ask for it with AUTO release. This is the stage that makes the record feel finished.

Everything is a detent. Ratio, attack, release and knee land on marked positions, so a setting you like is a setting you can write down and find again on the next song.

The order is yours: VARI-MU → VCA to level the program first and catch what escapes, or VCA → VARI-MU to take the peaks off before the tube stage ever sees them. The panel follows the order you pick, so the stage that runs first is the one on the left.

The difference, row by row

	Vari-Mu	VCA
What it reads	Program level, the way a needle does	Peaks, the moment they arrive
How it takes hold	No corner to the curve, so it never audibly grabs	The ratio and knee you dialled, exactly
Its main control	COMPRESSION, which is drive into the cell, not a threshold to chase	THRESHOLD and RATIO, from 1.5:1 to 20:1
Times	Attack 60 ms to 1.5 ms, release 2.5 s to 90 ms, and the release stretches when it has been working	Attack 0.1 to 30 ms, release 0.1 to 1.2 s, or AUTO
What it leaves behind	Density, and second and third harmonic you can dial from 0 to 100 percent	Punch, and a peak that stays where you put it

Two stages in series are only worth more than one stage twice if they behave differently, so every choice that could go either way went the other way on the second stage. Each keeps its own sidechain high pass, its own stereo link and its own wet / dry mix, so either one can be run in parallel without the other following it.

It shows you which stage is doing the work

Stage balance. One bar splitting the total gain reduction between the two stages, with the numbers beside it. When the vari-mu is doing all of it, you can see that before you can hear it.
Monitor. Audition the vari-mu alone, the VCA alone, or DELTA — only what the pair removed. Nothing else in the chain changes while you listen.
Crest in, crest out, delta. How much peak-to-average range went in, how much came out, and the difference. The measurement that says whether you have controlled the dynamics or flattened them.
Threshold link. Move both thresholds together to rebalance the whole machine, then unlink and trim one stage on its own.
46 samples of latency, whatever the rate. About a millisecond at 44.1 kHz, constant, and reported to the host so it compensates automatically. It is the valve stage running at twice the sample rate, which is the difference between a tube that colors and a tube that aliases.

The vari-mu stage of RSL Bastion, showing its two tubes, the COMPRESSION control and the output meters. — The vari-mu stage under load: the tubes light with the work, and COMPRESSION drives the cell rather than chasing a threshold.

What else is on the panel

Stereo, dual mono or mid / side. Chosen at the input, so the whole machine follows it. The stereo link blends each channel toward the louder of the two rather than their sum, which is what stops a hard-panned transient pulling the image around.
Headroom. +6, 0 or −12 dB. A calibration rather than a level control: it drives both stages harder or softer against their thresholds and takes exactly the same amount back out, so the only thing it changes is how hard the machine works.
Sidechain high pass per stage. Off, 60, 120 or 250 Hz, with a listen switch, so the kick stops deciding what the whole mix does.
Global mix. Blended against the true input, before the input gain, so a parallel setting is measured against your unprocessed mix and not against a different level of the same thing.
Bass mono and a true-peak ceiling. Both optional, both at the end, for the last plugin on the bus.
Seven factory starting points. Bus Glue, Mix Buss Weight, Master Gentle, Peak Control, Parallel Weight and Loud and Controlled, plus Init for a machine that does nothing until you tell it to.

How to get it

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RSL Bastion

$69once

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Specifications

Stages: Vari-mu program compression and discrete VCA peak compression, in either order
Formats: AU, VST3, AAX, Standalone on macOS 11 or later; VST3, Standalone on Windows 10 or later (64-bit)
Hosts: Logic Pro, Pro Tools, Ableton Live, Cubase, Studio One, Reaper, Bitwig and FL Studio
System: macOS 11 or later, or Windows 10 or later (64-bit)
Architecture: Universal 2, native on Apple Silicon and Intel
Channels: Stereo, dual mono or mid / side, chosen on the panel
Sample rates: Whatever the session runs at, 44.1 kHz to 192 kHz
Latency: 46 samples, about 1 ms at 44.1 kHz. Constant at every sample rate, and reported to the host
Interface: Scales from 70 to 200 percent, and the size is remembered with the session
Placement: Mix bus, stem bus or master bus. It is a dynamics processor, so it goes where you would put one
Availability: $69, regular price $99. Available now, activated through RSL Hub on up to 4 computers

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