PIONEER EXCLUSIVE C7

Pre owned. In good condition. They show some minor signs of wear. The preamplifier is supplied with its original packaging, only one original packaging box for the power amplifiers.

Pioneer Exclusive C7

Stereo preamplifier designed with the aim of minimizing transmission errors between the two channels and maintaining the signal paths of the right and left channels as uniform as possible. The design adopts a completely independent structure for each channel, from the power supply section through to the input and output terminals on the rear panel, with a symmetrical and physically separated internal component layout.

The design also takes into account the effects of magnetic fields, temperature and vibrations on the reproduction of the two channels. For this reason, transformers designed to operate with a low magnetic flux density are used, together with power supply capacitors designed to mutually compensate for the magnetic fields generated by the positive and negative poles. The die-cast aluminum chassis contributes to vibration and resonance control, while the printed circuit boards are mechanically isolated using supports made from materials specifically selected for vibration damping.

Thermal management is also considered in the circuit design. The arrangement of the components and heat sources is designed to maintain temperature conditions as uniform as possible between the two channels, limiting variations in the electrical characteristics of conductors and other components caused by heat.

The amplification circuit uses a configuration with two amplifiers and two buffers per channel. One buffer is positioned between the input selector and volume control, while a second is placed between the volume control and phase selector, allowing these stages to be driven at low impedance from a high-impedance source. The two flat amplifiers use circuits built with Hybrid ICs featuring aluminum substrates, selected for their thermal conductivity and shielding characteristics.

The power supply is divided among three independent transformers dedicated respectively to the left channel, right channel and control circuits. The transformers are designed to operate at low flux density, with the aim of limiting noise generation and reducing the influence of magnetic fields on the audio circuits. The smoothing capacitors also employ a complementary configuration designed to compensate for the magnetic fields generated by the positive and negative sections of the power supply.

The input section uses a separate ground circuit that allows the signal and ground conductors to be disconnected simultaneously. This solution limits the possibility of interference from other equipment connected to the system being transferred to the preamplifier through the ground line.

The volume control and function selection systems are designed to maintain channel independence. The Pioneer Exclusive C7 uses a remote-control mechanism integrated into the chassis, allowing the selectors and volume control to be operated while maintaining physical separation between the right and left circuits. When the controls are operated manually from the front panel, the selectors located at the rear are positioned by motors; once the operation is completed, the drive system is deactivated, preventing the control circuit from remaining active during listening.

The signal-path wiring uses shielded OFC copper conductors with 99.99% purity, while power is supplied to the three transformers through a six-conductor power cable made from large-gauge OFC copper. The wiring insulation uses a double-insulation structure and carbon as a pigment in the insulating material, a solution adopted to limit the influence of the insulating material's characteristics on the signal.

Pioneer Exclusive M7

Monoblock power amplifier designed for Class A operation, a configuration that inherently eliminates crossover distortion and distortion associated with switching processes. The design clearly separates the voltage amplification and current amplification stages, with the aim of improving loudspeaker drive capability, even with demanding loads, while keeping distortion under control.

The voltage amplification stage uses a Hybrid IC with an aluminum substrate and employs a negative-feedback configuration to achieve precise signal amplification. The output stage adopts a five-stage Darlington structure, with two driver transistors in parallel and six power transistors per rail in a parallel push-pull configuration. This architecture provides high current-delivery capability while maintaining low distortion levels even in the power stage.

The voltage amplification and power stages are also physically separated within the chassis in order to limit mutual interference. The design uses a signal path without a feedback loop from the output to the input, a solution intended to reduce the influence on reproduction of unwanted signals generated by loudspeaker behavior and high-frequency interference picked up by the speaker cables.

The internal construction follows a symmetrical approach between the positive and negative power-supply rails. The circuit layout, temperature distribution and mechanical structure are designed to maintain conditions as uniform as possible on both sides, reducing the effects on distortion caused by thermal variations, magnetic fields and mechanical deformation of the chassis.

The power supply uses a high-capacity toroidal transformer characterized by low leakage flux and good regulation stability. The large-gauge windings help reduce source impedance and limit temperature rise during operation. Two separate transformers are dedicated respectively to the positive and negative power supplies, while a dual-bridge rectification system helps reduce power-supply impedance and improve loudspeaker control.

The output stage uses a protection circuit designed without relays directly inserted into the signal path. This solution reduces the number of contacts along the audio path and limits the influence of the protection circuit on signal transmission.

The chassis uses thick aluminum materials and a structure designed to maintain mechanical rigidity and limit deformation caused by external vibrations and heat generated during operation. The power transformer is installed using a floating mounting system that helps reduce the transmission of vibrations to the chassis.

Thermal dissipation is provided by large heatsinks arranged to maintain the temperature as uniform as possible between the positive and negative rails of the amplifier. The various circuit sections are also separated by shielding in order to limit electromagnetic interference between the different stages.

The inputs include both an unbalanced RCA connector and a balanced input with an XLR-type connector, allowing the amplifier to be integrated into different system configurations.

The loudspeaker terminals are screw-type, designed to accept large-gauge cables, and feature gold-plated contacts to promote a stable connection.

The transformers dedicated to the positive and negative rails are powered using a six-conductor, large-gauge OFC copper cable selected for its conductivity. The cable also features a double-insulation structure and selected covering materials; the plug indicates polarity to facilitate correct connection to the AC mains.

The Pioneer Exclusive M7 is built using carefully selected components for the various stages, including transformers, transistors, integrated circuits and chassis materials. Each unit is also subjected to functional testing and listening evaluation before being released for sale, with the aim of assessing aspects of reproduction that cannot be identified through instrumental measurements alone.

Technical specifications – Exclusive C7:

• Type: stereo preamplifier
• Input sensitivity / impedance: Phono MM: 2.5 mV / 50 kΩ; CD, Tuner, Line 1, 2, 3, 4, 5, Tape Play 1, Tape 2: 150 mV / 50 kΩ; Balance In 1, 2: 150 mV / 600 Ω
• Output level / impedance: Tape Rec 1, 2: 150 mV / 1 kΩ; Output 1: 1 V / 0.1 Ω; Balanced Output 2: 1 V / 200 Ω
• Maximum output level (0.01% distortion, 20 Hz – 20 kHz): Tape Rec 1, 2: ≥12 V (with Phono input); Line 4, 5 Out: ≥12 V (with Phono input); Output 1: ≥5 V / 600 Ω; Balanced Output 2: ≥3 V / 600 Ω, ≥5 V / 10 kΩ
• Maximum Phono input level: Phono MM: ≥200 mV (1 kHz, 0.01% distortion)
• Signal-to-noise ratio: Phono MM: 87 dB; Aux: 105 dB
• Power supply: 100 V AC, 50/60 Hz
• Power consumption: 70 W
• Dimensions (W × H × D): 460 × 158 × 446 mm
• Weight: 27.5 kg

Technical specifications – Exclusive M7:

• Type: Class A monoblock power amplifier
• Rated output power: 480 W at 2 Ω; 240 W at 4 Ω; 120 W at 8 Ω
• Input sensitivity / impedance: Input 1 (coaxial): 1.0 V / 10 kΩ; Input 2 (balanced): 1.0 V / 2.2 kΩ (pin 3 hot)
• Output terminals: loudspeakers: 2 – 8 Ω
• Frequency response: 5 Hz – 100 kHz, +0 / -1 dB
• Damping factor: 100 (8 Ω)
• Signal-to-noise ratio: 120 dB (A-weighted, input shorted)
• Power supply: 100 V AC, 50/60 Hz
• Power consumption: 440 W
• Dimensions (W × H × D): 460 × 220 × 441 mm
• Weight: 47 kg