If you're looking for an AI-powered tool to generate custom VST synthesizer presets, Beat Shaper is a great choice. It creates VST synthesizer patches based on your style, as well as other elements like beats, basslines and melodies. The tool is designed to help you work faster and overcome creative blocks, giving you full control over the output and ownership of the generated content.
Another tool worth checking out is WavTool, a web-based app that uses generative AI to help you work faster. It includes an audio generator, stem separation and support for VST & AU plugins. WavTool's customizable interface and cloud saving means your projects are safe and accessible, and it's good for musicians at any level.
Also worth a look is Fadr, which has a SynthGPT option for turning text into playable instruments. It's geared more toward remixing and stem extraction, but it can be useful if you want to generate sounds on the fly. Fadr offers a variety of pricing tiers, including a free option, depending on how much you use it.
If you're looking specifically for synthesizer preset generation, MicroMusic is a dedicated site. It converts audio samples into Vital synthesizer presets, automating the process and providing a simple interface for quick results. MicroMusic is available as a one-time license or monthly subscription, so it's a good option if you need to churn out professional-sounding presets.