Synthv1 (ver. 0.7.2 shown above) is an old-school subtractive softsynth designed and developed by Rui Nuno Capela, and is part of the Vee One Suite (which includes Samplv1 and Drumkv1). It can run as a standalone synth or as an LV2 plugin within a DAW setup such as Ardour or QTractor. It can run in a Jack or Non Session Management (NSM) session, and has Jack Midi and Alsa Midi support.
Synthv1 has both polyphonic and monophonic capability, as well as velocity and aftertouch sensitivity controls. The layout is such that there are two identical pages, nominated Synth 1 and Synth 2, plus a third (effects) page. Each page includes a DCO section, a Filter section, an Amplitude section, an LFO section, a controller section and a general output section. The output section controls the audio level with respect to the other page's output, as well as an effects level knob.
Each page's oscillator section includes two waveform selectors, with the classic waveforms: pulse, saw, sine, random and noise. A setting of zero (when set to pulse) will deactivate the oscillator. The width knobs modulate the waveform in various ways: pulse-to-square, saw-to-triangle, sine-to-skewed sine.
Detuning of plus and minus four octaves, plus fine detuning. Portament (glide) and a global adjustment for the ADSR envelopes is located in the upper righthand section.
The Filter section provides four 12-dB, 24-dB and bi-quad filter types: lowpass, highpass, bandpass and band-reject. There is also a formant filter. There are full ADSR envelopes provided for both filter and amplitude, as well as another ADSR envelope for the LFO section. The LFO has a BPM control that can be synced to the transport or host rate.
The "DEF" section has controls for setting pitchbend, modulation and velocity. The Effects Page (not shown in screenshot above) provides various types of effects: chorus, flanger, phaser and delay, as well as a compressor and a limiter.
A nice collection of sounds created by Autostatic: Autostatic's Bank
A bank of presets for SynthV1 at KVR audio: Soundbank by kobraji
A small preset bank of mine, updated Sept. 28, 2016: SynthV1Patches