Accuphase C-3900 User Manual

PRECISION STEREO PREAMPLIFIER

●Dual Balanced AAVA volume control ● High-gain discrete current feedback type input amplifier ● ANCC technology minimizes noise and distortion ● Newly developed volume sensor construction ● Separate toroidal power transformers for left and right ● Newly developed filtering capacitors ● Separate unit amplifiers for left and right ● Printed circuit boards using glass cloth fluorocarbon resin

●Wood cabinet with natural grain finish ● High-performance headphone amplifier

The culmination of half a century of Accuphase preamplifiers

The Dual Balanced AAVA design with two balanced AAVA circuits delivers sonic excellence that is transparence itself. Volume adjustment is realized while retaining all the vibrant energy and richness of detail that is the life breath of an artistic performance. The supple elegance of music as reproduced by the top-of-the-line C-3900 is a moving experience that reflects the impressive depth of Accuphase know-how.

Innovation ‒ e leading edge of technology

■Developing a new preamplifier

To celebrate the 50th anniversary of Accuphase's founding, the development of a new flagship model to incorporate the entire wealth of the company's experience was begun. Now, after five years, the work is complete. The C-3900 represents an uncompromising harmony of technology and sensibility, boasting ultimate performance and sound quality that ushers in a new era of the preamplifier.

■Revolutionary AAVA volume control

Conventional preamplifiers attenuate the input signal by means of resistors and then amplify the result, which invariably leads to an increase in noise. AAVA on the other hand eliminates the entire step of resistor-based input signal attenuation. With this breakthrough principle, direct volume adjustment is performed through a combination of V-I (voltage-cur- rent) 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 depending on the selected volume position are kept to an absolute minimum, thereby realizing outstanding S/N ratio also at commonly used listening levels.

■Dual Balanced AAVA takes AAVA to new heights

In the C-3900, the Balanced AAVA principle which involves two balanced-connection AAVA circuits is further elevated by driving two such units in parallel, resulting in the Dual Balanced AAVA topology with significantly improved electrical characteristics. Compared to previous models, the already excellent noise level is reduced by a further 30 percent.

■High-accuracy, high-rigidity volume sensor construction

The volume sensor mechanism performs the task of detecting the angular position of the volume knob. Accuphase has developed the volume sensor in-house, using a massive aluminum block extruded and finished with utmost precision. The knob provides 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.

The progress of AAVA

Balanced

AAVA

Dual

Balanced

AAVA

			Noise level
			AAVA
	input		AAVA
	Balanced

30%

Balanced input

Balanced

output

	AAVA
	AAVA
	Balanced AAVA
	AAVA
	AAVA

Balanced

output

		Balanced AAVA
Balanced AAVA (2010)		Dual Balanced AAVA (2020)
Left-channel	Left-channel	Right-channel	Right-channel
	filtering capacitors	filtering capacitors
Dual Balanced AAVA			Dual Balanced AAVA

Left-channel	Right-channel
headphone amplifier	headphone amplifier

■ Dual Balanced AAVA with separate configuration for left and right channels

■ Dual Balanced AAVA printed circuit boards using glass cloth fluorocarbon resin substrate