Accuphase C-3900S Preamplifier

Accuphase C-3900S Preamplifier with Dual Balanced Volume Control

The C-3900S is a world-class preamplifier and the flagship in Accuphase’s illustrious lineup. Accuphase has addressed the issue of variable resistance with their original AAVA technology, which evolved into Balanced AAVA, and later became Dual Balanced AAVA. The Dual Balanced AAVA with ANCC installed in the C-3900S represents circuitry technology that achieves the ultimate in volume control. The C-3900S is a premium preamplifier for breathing life into deeply emotional performances and songs.

Revolutionary AAVA Volume Control

Accuphase Analogue Vari-gain Amplifier technology eliminates the entire process of resistor-based input signal attenuation. With this breakthrough principle, direct volume adjustment is performed through a combination of V-I (voltage-current) conversion circuits of different gain. As a consequence, there are no changes in impedance or frequency response and sound quality remains impeccable. Any changes in noise level related to the selected volume position are kept to an absolute minimum, thereby realizing an outstanding S/N ratio also at commonly used listening levels.

Dual Balanced AAVA takes the Concept to New Heights

In the C-3900S, the Balanced AAVA principle which involves two balanced AAVA circuits is further elevated by driving two such units in parallel, resulting in the Dual Balanced AAVA topology with significantly improved electrical characteristics. This creates a 30% reduction to the already excellent noise level achieved by models with Balanced AAVA.

ANCC Vastly Reduces Distortion and Noise

The Accuphase Noise and distortion Cancelling Circuit uses a secondary amplifier to cancel out noise and distortion from the main amplifier. The secondary amplifier utilizes a low-noise amplifier to increase the effect of the ANCC. Incorporating this ANCC into the Dual Balanced AAVA I-V conversion amplifier drastically improves noise suppression performance, particularly when transitioning from low volume settings to typical volume positions.

High-Accuracy, High-Rigidity Volume Sensor Design

The volume sensor mechanism detects the angular position of the volume knob. Accuphase has developed the volume sensor in-house, using a massive aluminium block finished with the utmost precision. The knob itself offers an utterly solid and smooth operation feel and achieves extremely accurate position detection.

When using the Remote Commander, a motor drives the volume knob via a set of gears. Generally, gears produce a meshing sound when rotating, but this position sensor is designed so that the gears mesh with each other while always maintaining a constant pressure, which enables super quiet and comfortable volume adjustment. 

Our Review

The Accuphase C-3900S is one of those rare preamplifiers that feels every bit as special as its world-class engineering suggests, blending an effortless listening experience with some truly next-level technology. At its heart is the remarkable Dual Balanced AAVA volume control with ANCC, a design that sidesteps traditional resistor-based attenuation to deliver impeccable purity, ultra-low noise, and rock-steady tonal integrity at any volume. The result is a preamp that brings performances to life with striking emotional depth, helped along by Accuphase’s beautifully crafted volume sensor, quiet motorised control, and an over-engineered power supply that keeps everything eerily silent. Add in a host of thoughtful touches - from discrete current-feedback input stages to a superb headphone amp and more inputs and outputs than most systems will ever need - and the C-3900S becomes not just a flagship, but a deeply satisfying centrepiece for anyone who loves music presented at its absolute best.