Verbos ElectronicsAmp & Tone VCF Filter + VCA

Verbos Electronics Amp & Tone

The Amp & Tone is a new version of Verbos's combination lowpass filter and VCA, retaining the all-discrete signal path, but redesigned in a smaller package. Now made with transistors, the two-pole Sallen-key lowpass filter features a vactrol CV path and controls for gain, cutoff, and resonance.

The filter resonance goes to self-oscillation, but can be tamed with the gain control. The resonance and the input gain interacts and can be used in tandem to create complex shaping to the input signal. The gain amplifies the input signal until it begins to clip at higher settings.

The VCA is inspired by the ARP 2600 and features linear and exponential control of the amplitude, which impart different sonic characteristics to the sound. The VCA's exponential response CV input is normalized to the VCF frequency, which also has an exponential response. Modulating the two together makes the Amp & Tone behave like a low pass gate, with quieter sounds being more filtered and louder sounds less filtered. The louder sounds are brighter and the quieter sounds darker, which mimics the way natural sounds behave. This redesigned module brings the same functions found in its older sibling and combines essential and powerful synthesizer functions in a smaller package.

Amp & Tone Features

• VCA and VCF
• Transistor-based Sallen-key lowpass filter
• All discrete signal path
• Gain goes into clipping
• Resonance self-oscillates at higher settings
• Both exponential and linear VCA CV responses
• Exponential CV normalized into VCF cutoff frequency
• All CV inputs feature attenuverters