Grandioso C1

The C1's two-chassis construction physically isolates the power supply from the audio circuitry. This allows the unit to create a sound stage having exceptional transparency, as well as providing a liberating sense of musical vibrancy, without betraying so much as a hint of stress.
The C1's separate 29kg linear power supply enables pristinely accurate amplification and ensures that the music signal is delivered to the power amplifiers without any loss of dynamics. This gives the music the power and vibrancy to captivate the listener. Due to the C1's monoblock internal construction, all the elements of each channel are completely independent: from the audio circuitry to the DC power supplies, and right down to the separate AC power cables. Creating the excitement of having every musical instrument accurately positioned before you, the C1 is the crystallization of an approach solely focused on accurate stereo sound reproduction.

The C1's main unit consists of two monoblock preamplifier modules and a logic control module. The input and output sections of each preamplifier module are constructed on separate boards, which are arranged one above the other in order to minimize the lengths of the signal paths. These modules are mounted on a unique leaf spring suspension system that was originally developed for Esoteric's leading lineup of SACD players. Its floating design helps achieve total left and right channel independence, and enhances the sense of spaciousness and ease in the sound.

The C1's DC power supply features a fully independent two-channel design with dual AC inputs and DC outputs. Together with the careful selection of components one would expect in such a reference product,this produces significant improvements in sound quality. Especially notable in the power supply's construction is the use of five generously rated power transformers, high-capacity reservoir capacitors and silicon carbide (SiC) Schottky barrier diodes.

All sections of the amplification circuitry are fully balanced, with the input buffer, volume control and high-speed output buffer laid out three-dimensionally to achieve the shortest possible signal paths. The C1's DC power supply provides a clean and stable output to each preamplification section, ensuring that the power amplifiers maintain full control of the loudspeakers, while at the same time preserving the music's delicacy and dynamics.

The C1's source signal is first received by the dedicated buffer amplifiers integrated with each of the five inputs (XLR x 3, RCA x 2), and the circuit configuration is balanced at each stage from there on. Through the elimination of common-mode noise and the reduction in circuit impedance,a pure signal, free from noise, is fed to the gain amplifiers via the shortest possible path.
The C1's volume control features Esoteric-QVCS.* This employs four precision switched resistor ladder networks, which change in unison when the volume knob is rotated. This arrangement allows the signal paths for the left and right channels and the positive and negative phases to be kept totally independent and as short as possible. Consequently the sound has superb clarity, excellent channel separation and a highly accurate phase characteristic.
*QVCS=Quad Volume Control System

In its function as a line driver, the preamplifier must have the ability to fully drive the power amplifiers in a way that faithfully conveys music signals that have an extremely wide dynamic range, extending all the way from pianissimo to fortissimo. The key to achieving this is having a circuit with both a high current drive capability and high speed. The C1's output buffer circuitry utilizes high-performance components to deliver a very high level of current drive, together with an exceptionally high slew rate of 2,000V/μs. Each output has its own independent drive circuit, and for the XLR outputs, the instantaneous output current capability is maximized by the use of fully symmetrical circuitry for both the hot and cold phases.
*HCLD=High Current Line Driver

The logic control section is built into the front panel and is totally isolated, both physically and electronically, from the preamplifier module by the use of an optocoupler. The logic control further ensures low-noise operation by completely shutting down when not in actual operation, totally eliminating any possible influence on the C1's audio circuitry.

The C1's input selector and volume knobs are machined from solid blocks of aluminum. The use of a VRDS drive mechanism bearing system for the control shafts enables silkily smooth rotation with absolutely no mechanical play in their movements. Rotational torque has also been fine-tuned to provide the luxurious feel of a precision analog control, in keeping with this top-of-the-line preamplifier.