RedGrooveBass: a free Ampeg SVT and B15 bass amp sim
v0.2.0 what's new
What’s inside
The bass chain of RedGrooveBass: compressor → octaver → auto-wah → preamp → chorus → cabinet. There are also a gate, a tuner and a limiter.
The cabinet is chosen from twelve factory presets of Orbit Bass Cab Builder.
The preamp is captured from a real Ampeg SGT-DI in NAM A2: both voices, B15 and SVT, across the whole range of the Grit knob. The NAM captures themselves can be downloaded on their own.
A walker on Teegarden b
We believe in humanity and the future, and we believe our place in space is not only at the bottom of a little planet’s ocean of air.
We are on Teegarden b, 12.5 light-years from Earth. Its star, a red dwarf, has a tenth of the Sun’s mass and is nearly twice as old. The planet gets almost as much heat as Earth, circles its star in 4.9 days and is tidally locked: on one side it is always day, on the other always night. We are on the terminator, the twilight belt between them. Here the sun stands on the horizon, four times bigger than ours, simply red. It never sets and never moves. Billions of years in one place. And it will stay in that same place for tens of billions of years more, long, long after our Sun swallows Earth.
We are on a walker. When we set out, we did not know exactly what surface we would be moving over, or even whether there would be a surface at all, so we had to stock up on machines of varying degrees of weirdness. The light here is dim and almost all infrared, and mushrooms don’t need light. The twilight belt has been taken over by a bioluminescent fungal forest: from knee-high caps to 24-meter towers, on a springy mat of mycelium, with glowing spores hanging in the air. The walker’s glass dome rides 6.6 meters up, its step is heavy, and every footfall leaves a print in the mycelium and kicks up a cloud of spores. For now this is only a reconstruction of the future, but people will make it here for sure. There are only two brakes: plain human stupidity, and stupidity elevated to a cult because it’s vintage.
What Ampeg is
Ampeg was founded in 1946 by Everett Hull, a pianist and double bass player. He put a microphone on the peg the instrument stands on, right inside the body, and in 1947 got a patent for it. The amplified peg, Ampeg for short. From 1949 the firm was called the Ampeg Bassamp Company and made amps for jazz double bass players.
In 1960 the designer Jess Oliver, a bass player too, made the B-15 Portaflex: a closed-back cabinet with a bass port, and the head flips over and hides inside it. He said he got the idea from a Singer sewing machine. The B-15 quickly became the most popular bass amp in the world.
Hull did not like rock. Ampeg’s catalogue for 1964 and 1965, when Hull ran the firm, says it plainly: "If the beat is important (and it is), heavy loud music is out of order. It simply doesn’t swing, never did, never will and cannot." In 1968 Hull left his own firm, and in 1969 the engineers Bill Hughes and Roger Cox showed the SVT, in Cox’s words "the biggest and nastiest bass amplifier the world had ever seen": 300 watts of tube power and two cabinets with eight ten-inch speakers each. The same year the SVT went on a US tour with the Rolling Stones. Since 2018 Ampeg has belonged to Yamaha Guitar Group.
In 2023 the SGT-DI pedal came out, with its SGT drive, and that is what we captured. Hull, say the people who worked with him, hated distortion. And distortion is exactly what we captured.
Download RedGrooveBass
| macOS | darwinscat-bass-0.2.0-macos.pkg | 35 MB |
|---|---|---|
| Windows | darwinscat-bass-0.2.0-windows-arm64.zip | 25 MB |
| darwinscat-bass-0.2.0-windows-x64-setup.exe | 14 MB | |
| darwinscat-bass-0.2.0-windows-x64.zip | 25 MB | |
| Linux | darwinscat-bass-0.2.0-linux-arm64.tar.xz | 19 MB |
| darwinscat-bass-0.2.0-linux-x86_64.tar.xz | 23 MB | |
| Checksums | SHA256SUMS | 633 B |
Frequently Asked Questions
What’s the difference between B15 and SVT?
The Ampeg SVT is a legendary amp from 1969: 300 watts of tube power and two cabinets with eight ten-inch speakers each. It stood right on stage and filled the hall: back then, the bass guitar wasn't run through the PA. That's the SVT.
The B15 is from 1960: a cabinet with one 15-inch speaker and a 25-watt tube amp that flips over and hides inside it.
How do I download a NAM capture from RedGrooveBass?
Right-click DRIVE. If DRIVE moves in steps, "Save the current sound as .nam…" saves the capture the knob stands on; if it moves smoothly, "Save the nearest capture as .nam…" saves the nearer of the two. The result is a normal .nam file for another NAM plugin or a NAM-compatible pedal. All 22 captures at once are on the Ampeg SGT-DI pack page.
Can I use your NAM captures and IRs in music, software and hardware?
Yes.
- Play, record, perform and sell music made with them: freely, no conditions.
- Share the files, including posting them on websites: with credit to Darwin's Cat.
- Build them into software or a device: if it is free itself, its source open under the GPL or AGPL, with credit to Darwin's Cat. Into a closed product only with our written permission.
Telling us where you used our NAM captures or IRs is optional, but we will be grateful for an email to band@darwinscat.com.
Which DAWs does RedGrooveBass work in?
Any that opens VST3, CLAP or AU. Logic Pro and GarageBand use AU (macOS only); Ableton Live, Cubase, Reaper, Bitwig and Studio One use VST3; Reaper and Bitwig also CLAP. On Linux, VST3 and CLAP. Without a DAW, the standalone app works.
Can I play without a cabinet?
Yes. The switch in the CABINET row takes the cabinet out of the sound, and the DI is left. And the CAB / DI fader mixes the cabinet with the DI in any proportion. Playing without a cabinet is handy when there is one further down the chain, for example Orbit Bass Cab Builder.
Is RedGrooveBass good for a five-string bass?
Yes. STR at "5" cuts everything below 22 Hz, that is below the low B, and the tuner hears notes from 25 Hz up. For a four-string, STR "4" cuts everything below 32 Hz.
How is RedGrooveBass different from OrbitBass?
Both play the same set of Ampeg SGT-DI captures and install as one package. RedGrooveBass has two gears with their own memory and the walker, and its panel is a fixed set of devices: the compressor has one knob, the twelve cabinets sit on a slider. OrbitBass is the whole bass chain: the compressor with all its knobs, all the presets of Orbit Bass Cab Builder and your own IRs, delay and reverb.
What keys does RedGrooveBass have?
1 and 2 are the B15 and SVT gears. A, B, C, D are the registers. Cmd+Z is undo, Cmd+Shift+Z or Cmd+Y is redo (Ctrl on Windows and Linux). G switches the gate on and off. Full screen in the standalone app: Cmd+Ctrl+F on a Mac, F11 on Windows and Linux; Esc leaves it. The ← and → arrows turn the walker while the dome's glass has focus, or the glass can be dragged with the mouse. A, B, C, D and G work in a Russian keyboard layout too.
Does RedGrooveBass work with MIDI?
Only the standalone app accepts MIDI; the plugin doesn't. Program Change 1 and 2 switch B15 and SVT; CC 23 is DRIVE, 24 BASS, 25 MID, 26 TREBLE.
Is RedGrooveBass really free? What does AGPL mean?
Yes, completely free: no sign-up, no keys, no ads. The AGPL is a free license: the source code is open to everyone. Music recorded with RedGrooveBass belongs to its author, commercial use included. Anyone who distributes a modified version of the program itself must open its code too.
Does RedGrooveBass track me?
No. RedGrooveBass goes online in two cases only. If you switch on the update check, it asks GitHub whether a new version is out: GitHub sees the IP address, the program's name and its version, nothing more. And if you click the cat on the panel, our website opens in your browser; it runs without cookies and without third-party trackers.
Why do you do this? Working for free is immoral by the logic of capitalism. Are you communists?
No, we are not communists. But we know that altruism is one of the most powerful weapons evolution ever invented. Not teeth, claws and poison spines, but altruism. We sing about it in our songs, for example in Eleven Light Years.
Is RedGrooveBass connected with Ampeg?
No. Ampeg, SGT-DI, SVT and B-15 are trademarks of their owner. We captured the SGT-DI and name it only to say what exactly we captured. The cabinets in RedGrooveBass are ours.
What about the logos?
In the download table, macOS has a pear scratched by a cat, and Windows has a window scratched by a cat, its tile falling off. We don't love Microsoft and Apple, if only because they make developers pay for the right to distribute their programs on their platforms, and on principle we don't use their logos. These logos are ours, and you can use them: the pear and the window as SVG.