Major refinements inside and out have taken the already solid performer to a new level

Technical Audio Devices Laboratories, Inc., today announced the TAD-C700 preamplifier as the newest addition to its Reference Series of hi-fi audio components.

The new TAD-C700 incorporates a slew of technical refinements and enhancements to achieve a new level of performance, replacing the TAD-C600, TAD’s critically acclaimed, top-of-the-line preamplifier released in 2011.

MAIN FEATURES

1) Immaculate preamplification circuit

The TAD-C700 boasts a high-performance, single-stage current-feedback amplifier in its flat amplifier section. The minimal use of amplifying elements enables the C700 to amplify every musical nuance faithfully. Furthermore, a dedicated output amplifier circuit provided to each of the two line outputs prevents signal branching and interference from connected equipment from deteriorating sound quality.

2) Fully balanced circuitry and dual-mono construction design

The C700’s fully balanced circuit topology amplifies positive and negative signal waveforms individually from input to output in order to suppress even the smallest amplification errors between positive and negative signals, as well as between right and left channels. The wire length and dressing are identical between positive and negative signal paths and between both channels, to achieve an ideal signal path from input to output. Furthermore, the dual-mono construction design of circuitry achieves maximum symmetry to provide identical amplification, both electrically and mechanically, to positive and negative signals and to both channels, which results in a near-perfect stereophonic sound reproduction.

3) Outboard power-supply unit

The C700’s power-supply unit is physically separated from the main amplifier unit. This ingenuous design prevents vibration and magnetic flux leakage from the transformer from adversely affecting mechanical sections and audio circuits of the main unit. To increase the purity of power supply, the internal coil of the transformer is directly connected to the power supply circuit, minimizing the contact points with leading wires. Moreover, terminals for directly connected coils, mounting terminals for motherboards, and clamping screws are all made of oxygen-free copper coated with nonmagnetic materials to eliminate even the slightest magnetic distortions. A powerful toroidal transformer with a 400 VA power rating—not uncommon in power amplifiers but unheard-of in preamplifiers— powers the audio circuit to achieve greater signal transition performance. The entire power supply is housed in a rigid cast-aluminum monocoque chassis to suppress unwanted vibrations.

4) Vibration-suppressing design

The C700’s main amplifier circuit is mounted on a sturdy 33-mm-thick sub-chassis weighing 15 kg, made from pure aluminum ingots, to achieve outstanding vibration control that minimizes the effect of vibrations from speakers. The use of pure aluminum ingots provides a stable, low-impedance ground path, contributing to high-purity reproduction of music.

5) TAD’s custom-made parts and components

TAD’s custom-made electronic volume control circuit boasts ladder-resistance switching that achieves exceptionally precise attenuation performance and an ultra-low distortion of less than 0.0005% at 1 Vrms input. In addition, the power circuit employs TAD’s custom-made electrolytic smoothing capacitors, as well as large-capacity, ultra-low-distortion film output coupling capacitors to achieve a wider low cut-off frequency range.

6) Synchronous control of multiple C700s

A master C700 can synchronously control several slave C700s connected to its MASTER OUT jack. This enables two or more C700s to provide a dual-mono configuration for monaural power amplifiers or to deliver three-or-more-channel sound reproduction.

7) Recording output and pass-through mode

The C700 is equipped with a dedicated recording output that bypasses the selector circuit to directly output input audio signals. It also has a pass-through mode that outputs input signals from a pre-out jack without changing the signal level. A monitor switch is not available on the C700 to eliminate any chance of switching elements adversely affecting sound quality.

TAD-C700 specifications

6 Input Terminals Balanced input x 4, unbalanced input x 2
4 Output Terminals Balanced output x 2, unbalanced output x 2
Rated Output Voltage Balanced output: 1.5 V; unbalanced output: 0.75 V
Maximum Output Voltage Balanced output: 20 Vrms; unbalanced output: 10 Vrms
Input Impedance Balanced input: 100 kΩ; unbalanced input: 50 kΩ
SN Ratio 120 dB
Frequency Response 10 Hz - 100 kHz （-1 dB）
Power Supply Voltage AC 120 V, 60 Hz (USA); AC 220 V to 240 V, 50 Hz /60 Hz (Europe, Asia)
Power Consumption 52 W (Power consumption during standby: 0.5 W or less)
Dimensions Main amplifier unit: 450 mm (W) x 150 mm (H) x 440 mm (D) Power-supply unit: 220 mm (W) x 185 mm (H) x 430 mm (D)
Weight Main amplifier unit: 29.0 kg
Power-supply unit: 15.0 kg