Apollo
Native
SSL 4000 G Bus Compressor
Get the ultimate “glue” for your mix bus.
- Mix with a jaw-dropping emulation of the iconic SSL G Bus Compressor
- Give power, cohesion, and drive to mixes, buses, or any source
- Harness new features like Side Chain Filtering, Mix, and Headroom controls
- Mix with artist presets from Just Blaze (Beyoncé, Kendrick Lamar), Peter Mokran (The Flaming Lips, Mary J. Blige), Ian Boxill I, and more
Get the Ultimate “Glue” for your Mix Bus
What They Say
Peter Mokran
Christina Aguilera, The Flaming Lips
Chris Coady
Yeah Yeah Yeahs, Beach House, Future Islands
Frequently Asked Questions
The Universal Audio SSL 4000 G Bus Compressor is worth it if you want the classic "glue" that ties a mix together and makes it sound bigger, punchier, and more cohesive. It is an end-to-end circuit emulation of the iconic SSL G Bus Compressor, endorsed by Solid State Logic, with modern additions like Side Chain Filtering, a Mix control, and Headroom. You get a studio-standard mix bus sound in software, so you can reach for it on every project without dedicated hardware.
The SSL 4000 G Bus Compressor stands apart because it recreates the specific circuit behavior of the SSL G bus compressor, the sound behind countless hit records. Its fixed Attack and Release times are SSL-voiced for bus duty, including the program-dependent Auto Release, so it glues a full mix together in a way general-purpose compressors do not. Added controls for Side Chain Filtering, wet and dry Mix, and Headroom give you shaping options the original hardware never had.
The SSL 4000 G Bus Compressor is UA's newer, more advanced emulation that goes further than the original SSL G Bus Compressor plug-in. It uses an end-to-end circuit model and adds tools the earlier version did not include, such as the internal Side Chain Filter, the Mix control for inline parallel compression, and the Headroom control. If you already own the original, the newer version is the one to reach for when you want those extra shaping controls and the fullest emulation.
You can get the SSL 4000 G Bus Compressor as an individual plug-in purchase or as part of a UAD Spark subscription, which includes it alongside the full library of UAD native plug-ins. Each license comes with three activations, which you can place on your computers or on an iLok USB key. A 14-day demo is available if you want to hear it on your own mixes before you decide.
Yes, the SSL 4000 G Bus Compressor is an expert end-to-end circuit emulation of the hardware SSL G bus compressor, and it is fully endorsed by Solid State Logic. UA models the actual circuit behavior rather than just the sound, so the plug-in responds the way the original unit does across everything from subtle leveling to heavier peak limiting. That accuracy is why engineers reach for it to get the authentic SSL bus character.
The SSL 4000 G Bus Compressor makes a mix sound bigger, punchier, and more cohesive by controlling the dynamics of the whole bus at once. At light settings it adds transparent control and a sense of cohesion, and pushing the continuous Threshold harder brings more aggressive movement and peak limiting for energy and drive. This is the "glue" effect that helps separate tracks feel like one finished record.
No, the SSL 4000 G Bus Compressor runs natively on your Mac or Windows computer with no Universal Audio hardware required. If you do own an Apollo interface or a UAD Accelerator, you can also run it accelerated on that hardware. Either way you get the same emulation, so you can start on your computer alone and expand your setup later.
Yes, the SSL 4000 G Bus Compressor runs natively on both macOS and Windows, including Apple Silicon Macs. It is a native UAD plug-in, so it installs and runs directly on your computer. For the current list of supported operating systems and versions, check UA's Native UAD system requirements page.
The SSL 4000 G Bus Compressor loads as a standard plug-in in your recording software, so it fits into the DAW you already use. It installs in the common native plug-in formats your software supports. An iLok account is required to manage the license, though an iLok USB key is optional.
To use the SSL 4000 G Bus Compressor on your mix bus, place it on your master or 2-bus and lower the continuous Threshold until the mix starts to move together. Start with a light touch for transparent cohesion, or push harder for full dynamic crush and drive. The SSL-voiced fixed Attack and Release, including Auto Release, are already tuned for bus work, so you mainly set the Threshold and makeup level to taste.
Yes, the SSL 4000 G Bus Compressor includes a Mix control for inline parallel compression with no extra routing. You blend the compressed signal against the dry signal right inside the plug-in, which is ideal for adding punch to a drum or vocal bus while keeping the transients intact. It saves you from setting up separate send-and-return channels to get the same effect.
The Side Chain Filter on the SSL 4000 G Bus Compressor lets you tailor how much low-frequency content drives the compression. Filtering the low end out of the detection path reduces the "pumping" caused by kick and bass, so the compressor responds to the overall mix instead of heavy low-end hits, giving you steadier, more musical compression.
Yes, a dedicated bus compressor like the SSL 4000 G Bus Compressor still earns its place in 2026 because gluing a mix together is a different job from track-level compression. A bus compressor shapes how all your elements move as one, adding the cohesion and punch that make a mix sound finished. Modern productions rely on this final stage just as much as the records that first defined the sound.
Yes, the SSL 4000 G Bus Compressor is built for professional and commercial work, and it recreates the bus sound heard on decades of hit records. It ships with presets from working mix engineers and producers, giving you proven starting points for real projects. Whether you work in a commercial studio or at home, it delivers a release-ready bus sound.
A bus compressor is a compressor placed on a group of tracks or the full mix to control their combined dynamics, and the SSL 4000 G Bus Compressor is a software model of the classic SSL G bus compressor built for exactly that job. Instead of shaping one instrument, it evens out the whole bus so the parts move together and sound cohesive. That shared movement is the "glue" that makes a collection of tracks feel like one record.