Sherbourn 7/2100A Multi-Channel Amp

Description

The Sherbourn 7/2100A is a formidable seven-channel power amplifier designed for serious home-theater systems, but its substantial power reserves and seven fully independent amplifier sections also make it an unusually capable choice for demanding multichannel music applications. Introduced during the era when high-performance separates were becoming increasingly popular among home-theater enthusiasts, the 7/2100A took a distinctly no-compromise approach: rather than using a single shared power supply, Sherbourn built the amplifier around seven individual monoblock-style channels and seven toroidal transformers. The result is an exceptionally heavy amplifier weighing approximately 115 pounds.

Rated at 200 watts per channel into 8 ohms and 300 watts into 4 ohms, the 7/2100A is designed to maintain substantial current delivery when driving difficult loudspeaker loads. Sherbourn specified less than 0.05% THD at 8 ohms and less than 0.075% at 4 ohms, with a very wide 5Hz–75kHz power bandwidth. The amplifier also incorporates more than 150,000 microfarads of filter capacitance and 56 bipolar MOSFET output transistors, giving it the power-supply resources expected of an amplifier intended to reproduce demanding movie soundtracks at realistic levels.

One of the 7/2100A’s particularly interesting features is Sherbourn’s Load Detection System (LDS). The system samples the signal and checks the connected load before allowing the amplifier to power up, providing an additional level of protection against potentially damaging speaker or wiring conditions. The amplifier also provides both balanced XLR and unbalanced RCA inputs, along with gold-plated five-way binding posts and a low-voltage trigger connection.

Another unusual feature is its ability to bridge selected pairs of channels. Channels 1/2, 3/4, and 5/6 can each be configured as bridged mono amplifiers, producing up to 400 watts into 8 ohms. This gives owners considerable flexibility in configuring the amplifier for different systems, although Sherbourn specifies an 8-ohm minimum load when operating in bridged mode.

The amplifier’s enormous power requirements are reflected in its two AC power cords. Sherbourn designed the 7/2100A to operate from two standard 15-amp circuits under typical U.S. conditions, avoiding the need for a dedicated high-current 20- or 30-amp circuit in many installations.

Contemporary and owner commentary emphasized the amplifier’s combination of power and build quality. One owner reported that even when driven very hard in seven-channel operation, the amplifier “never distorted or even sounded like it was straining.” Another long-term owner described it as “extremely musical not only for home theater but for two channel as well,” while another owner characterized it simply as “built like a tank” and said it would handle essentially anything connected to it.

For enthusiasts assembling a high-output surround system, the Sherbourn 7/2100A remains an impressive example of old-school amplifier engineering. Its enormous transformers, independent channels, massive chassis and generous power supply make it far more substantial than the typical AV receiver’s built-in amplification. Its principal drawback is equally obvious: at roughly 115 pounds and with two power cords, installation and placement require some planning. For those willing to accommodate its size and weight, however, the 7/2100A offers an impressive combination of power, flexibility and serious-build construction.

Review & Owner Impressions

• “Never distorted or even sounded like it was straining” — owner report after running the amplifier hard in seven-channel operation.
• “Extremely musical not only for home theater but for two channel as well” — long-term owner assessment.
• “Built like a tank” — owner description emphasizing the amplifier’s heavy-duty construction.

Product Specifications

• Type: Seven-channel power amplifier
• Channels: 7
• Power Output: 200 watts × 7 into 8 ohms
• Power Output: 300 watts × 7 into 4 ohms
• Bridged Output: Up to 400 watts into 8 ohms
• THD: <0.05% at 8 ohms; <0.075% at 4 ohms
• Frequency/Power Bandwidth: 5Hz–75kHz
• Signal-to-Noise Ratio: 100dB wideband; 110dB A-weighted
• Input Sensitivity: 1.1V
• Input Impedance: 20k ohms, balanced or unbalanced
• Speaker Load: 4–8 ohms normal operation; 8 ohms minimum bridged
• Inputs: Balanced XLR and unbalanced RCA
• Speaker Connections: Gold-plated five-way binding posts
• Protection: Sherbourn Load Detection System (LDS)
• Trigger: Low-voltage/12V trigger input
• Power Supply: Seven toroidal transformers; more than 150,000µF capacitance
• Output Devices: 56 bipolar MOSFET transistors
• Power Requirement: 120V; two 15A connections
• Dimensions: 19″ W × 7″ H × 17.7″ D
• Weight: Approximately 115 lb (52.2 kg)