Bass One is a free software synthesizer developed by Dario Lupo / Daze. Available format(s): VST for Windows.
Bass One is an easy to use 3-oscillator bass synthesizer
http://www.dazesounds.com/

Free Audio Plugins & Softwares. All the Best VST & Audio Units Available for Free.
Badass is a free sample based Kontakt instrument produced by DCSI.
Wrapped in a 30 MB instrument size it’s a sampled and edited old school bass synth, spread across 3 octaves, coming with some optional gritty flavour added by using the modwheel of your controller, plus a delay effect and several play modes.
Badass plays at its best with the mono/unisono settings on, available on the GUI.
A PDF manual with more details and license agreement is included in the download.
This DCSI Kontakt instrument was built with the Kontakt 5.3 version.
To download it please join and like DCSI on Facebook at: www.facebook.com/DiegoCallegariSoundsImages and you’ll be able to grab it for free through the “Free Downloads” tab there.
https://dcsiproductions.blogspot.com/
Baby Piano is a ROMpler / sample player that uses the natural samples of the Baby Piano sample set from Les Productions Zvon.
It has 7 controls to tweak the playback of the samples:
- Volume.
- Pan, Attack.
- Release.
- LFO rate.
- LFO Depth.
- Reverb.
It cannot import samples.
http://www.lesproductionszvon.com/
B8 Organ is a reproduction of the old organs of the ’60s and ’70s. It has 9 oscillators, switchable between sine and saw wave, with drawbars, vibrato, chorus and reverb. Sine waves result in tones typical of a church organ, or “hammond-type” sounds. Saw waves sound more like old combo organs, like Farfisas, Davoli, Crumar, for example.
http://www.autodafe.net/
Sonex Audio has released Free B290 Grand, an massive 7 GB Bosendorfer 290 Acoustic Piano for NI Kontakt Sampler.
Features:
- Legendary Bosendorfer 290 Acoustic Piano.
- 4 separate mic positions: close (stereo and mono), middle, far, and ambience (room).
- Up to 12 velocity layers.
- Nearly 31GB of uncompressed sample content (compressed to 7 GB).
- 3.157 Samples (Kontakt Lossless Sample Compression format).
- Built-in Effects: 3-Band Equalizer, Compressor, Saturation, Distortion, Chorus, Reverb, Delay, Stereo Width, Limiter and more.
- Full set of effects in the Kontakt settings for further customization.
- Unique GUI has been designed to give a user full control over options and effects without slowing down the creative process.
Price: Free. Full Retail Version of NI Kontakt 5.6 or later required.
A link to download the library is in the description of the full instruments collection.
https://www.sonex.store/
B-station 2 is a simple but powerful bass plugin.
Features:
- 3 oscillators: Every oscillator has a fine tune, octave, pw, volume and 5 different waveforms.
- Mod oscillator for Pulse width and for phase modulation.
- 4 filters types: Low-pass / band-pass / hi-pass / 4-pole. The filter has an envelope ADSRLT, 12 curves and a BPM LFO.
- Modulation Envelope for pitch and Pulse width.
- Vibrato, Bitcrusher, Drive, Low- / Hi-boost.
- Arpeggiator.
- Velocity filter and volume on / off.
- Glide / Retrigger and a master volume.
https://theodosynthsarchive.wordpress.com/
Features:
- 3 instruments.
- 9 drawbars.
- 6 different waveform shapes.
- Click.
- Percussion.
- Sustain.
- Split mode.
- Monophonic mode (perfect for bass sounds).
- Vibrato.
- Scalable pitch bend.
- Saturation/distortion/fuzz.
- Rotating speakers. Lower speaker can be switched between fixed and rotating.
https://sourceforge.net/projects/zr-3/
Features:
- 6 voice polyphonic.
- 3 oscillators (Saw, Sine, Tri, Pulse, Ramp, White Noise, Pink Noise).
- Resonant filter.
- 3 LFOs with various modulation options.
- Chorus and Distortion.
http://azeta66.altervista.org/