Asheville Music Tools ACV-NOS Analog Chorus/Vibrato

The ACV-NOS Edition is 100% analog and utilizes over 350 carefully selected components including premium audio-grade op amps and high-tolerance, non-microphonic capacitors to guarantee high performance, temperature & voltage stability, low noise, and maximum headroom.

Asheville began with a classic chorus architecture using a 1024 stage New Old Stock Matsushita (Panasonic) BBD and a step-up boost power supply for maximum headroom. They then implemented a vintage-style compander with emphasis/de-emphasis coupled with discrete transistor, 5th-order, anti-aliasing and reconstruction filters to maximize the range of delay times without undesirable artifacts. The feedback circuit uses a synthesizer-style VCA to provide a classic, warm regeneration tone while offering an accurate method of dialing in the perfect amount of musical peaks and notches.

The input preamplifier includes a discrete, high impedance, JFET stage that can also be used as an always-on buffer. Asheville also included some soft limiting to provide character with hot signals and prevent transients from overloading the delay section.

The clock, modulation, oscillator, and even the switch logic are all fully analog. The clock VCO includes a temperature-compensated exponential converter for a wide, even range modulation. The clock drives the BBD at extremely high current to eliminate artifacts and provide a clear, tight sound with consistent gain. An assignable expression input increases the flexibility and control available to the user.

Power and grounding deserve special attention. The ACV-NOS is designed using a multi-layer PCB with dedicated split power and ground planes for low noise and crosstalk. The power input is fully protected from reverse polarity, over-voltage conditions, and ESD spikes. Our custom-designed 9V to 15V power supply works conveniently with standard 9V pedal power supplies, and eliminates sources of noise and radio frequency interference (RFI/EMI). Its boost technology runs at MHz frequencies to eliminate artifacts usually associated with simpler charge pump or older style converters.