Sunfire Cinema Grand 5-channel Power Amp

Description

The Sunfire Cinema Grand is one of the landmark multichannel power amplifiers of the 1990s, combining Bob Carver’s unconventional amplifier engineering with the demands of the emerging Dolby Digital and DTS home-theater era. Introduced in the mid-1990s, the original Cinema Grand delivered a formidable 200 watts per channel into 8 ohms, with all five channels driven, while its unusual power supply allowed substantially greater output into lower impedances. At its original $2,375 price, it was positioned as a high-performance alternative to using several separate stereo amplifiers.

The key to the Cinema Grand’s remarkable power-to-size ratio is Bob Carver’s Tracking Downconverter power supply. Instead of using a conventional large linear supply that continuously maintains high rail voltages, the Sunfire system dynamically tracks the amplifier’s requirements. This allows the supply voltage to remain relatively close to the instantaneous output requirement, reducing wasted heat while permitting enormous bursts of current when demanded by the music or soundtrack. Contemporary Audio testing noted that the amplifier could deliver 200 watts per channel into 8 ohms, 400 watts into 4 ohms and 800 watts into 2 ohms for a limited period, yet operated without a cooling fan or large external heatsinks.

Another unusual feature is the provision of both voltage-source and current-source outputs. The conventional voltage-source connection has extremely low output impedance and is intended for normal loudspeakers. The higher-impedance current-source output was intended for certain electrostatic, planar-magnetic and ribbon speakers, and was one of Carver’s more distinctive attempts to give users the ability to tailor amplifier/speaker interaction. Sunfire literature described the current-source connection as offering a warmer, more open character.

The Cinema Grand also has a surprisingly minimalist appearance. Its brushed-aluminum and black-anodized chassis incorporates a central illuminated power-supply energy meter, while the amplifier rests on a separate glass base. An auto-on circuit could activate the amplifier when a signal was detected, a useful feature for home theater installations. Inputs were provided in both balanced and conventional unbalanced forms.

Contemporary reviews were enthusiastic about its combination of power and efficiency. Audio called the Cinema Grand’s output capability “prodigious” and specifically praised the cool-running design. A later Sunfire brochure quoted a Home Theater review saying, “Dialog sounded very warm and refined,” and describing the amplifier as “easily of reference caliber.”

For a vintage home-theater or two-channel system, the original Cinema Grand remains an especially interesting piece of Carver engineering. Its five channels, substantial current capability, current/voltage-source outputs and efficient Tracking Downconverter supply make it considerably more sophisticated than its relatively simple exterior suggests.

Review Quotes

• Audio: The Cinema Grand’s power capability was described as “prodigious,” while its ability to operate without a fan or conventional heatsinks was particularly noteworthy.
• Home Theater: “Dialog sounded very warm and refined,” with the amplifier described as “easily of reference caliber.”
• Audio: Contemporary coverage emphasized that the amplifier could deliver tremendous output while running remarkably cool because of its Tracking Downconverter supply.

Product Specifications

• Type: Five-channel solid-state power amplifier
• Manufacturer: Sunfire Corporation
• Designer: Bob Carver
• Era: Introduced 1995–1996
• Rated power: 200 watts × 5 into 8 ohms, all channels driven
• Power into 4 ohms: 400 watts/channel
• Power into 2 ohms: 800 watts/channel, time-limited
• Frequency response: 20 Hz–20 kHz, ±0.1 dB
• THD: Less than 0.5%
• Signal-to-noise: Approximately 100 dB, A-weighted
• Input sensitivity: 1.3 V RMS; balanced input also provided
• Input impedance: 24 kΩ unbalanced
• Output types: Voltage-source and current-source
• Maximum output current: 80 amperes peak-to-peak/channel
• Power supply: Bob Carver Tracking Downconverter
• Inputs: Balanced and unbalanced
• Auto-on: Signal-sensing turn-on
• Chassis: Brushed aluminum/black anodized finish
• Dimensions: 19 × 6.5 × 15.75 inches
• Weight: Approximately 45 lb.