Vanguard is a VSTi and AU software synthesizer by German independent publisher reFX.
Released in 2004, it is a virtual analog synthesizer with three oscillators, 32 waveforms, up to 10-times unison, a filter with a number of frequency responses, delay and reverb effects and stereo pattern controlled noise gate and arpeggiator, making this plugin useful among the electronic dance music producers. Most functions can be automated, such as cutoff frequencies, resonance, ADSR, and LFO. Vanguard works with any VST-capable host and features the Trancegate and Arpeggiator tools. The audio engine and a part of the factory sounds from Vanguard were programmed by Markus Krause from Tone2 Audiosoftware.
This synthesizer is used by many electronic dance music producers, however is not as prevalent as reFX's Nexus 2 ROM plugin. Nexus2 is so called because it replaced the upgraded 2007 package for Vanguard called "Nexus ROM" in early 2008.