Great care has been taken by ADCOM to assure that your 5-channel power amplifier is as flawless in appearance as it is electronically. The front panel is a heavy- gauge, high-grade aluminum extrusion carefully finished and anodized for durability. The chassis, top cover and rear panel are of heavy-gauge steel, both painted and baked. If the front panel, top or sides should become dusty or fingerprinted, they can be cleaned with a Swifter and/or a clean, soft, Lintless, microfiber cloth,slightly dampened with a very mild detergent solution or nonammonia glass cleaner.

Home theater authority — all five channels, no compromise.

The Adcom GFA-5705 is a high-performance 5-channel power amplifier engineered specifically for home theater systems that demand real power across every channel. Delivering 200 watts per channel into 8 ohms — with all five channels driven simultaneously — the GFA-5705 brings the same high-current authority and low-distortion performance Adcom is known for to the full surround experience.

The GFA-5705 is built to drive a very broad range of loudspeakers, including those with very low impedances, at sustained high-power levels — even when impedances are highly reactive. Great care was taken to ensure distortion remains extremely low under these demanding conditions, making it one of the most capable 5-channel amplifiers available at its price point.

Massive Power Supply

At the core of the GFA-5705 is a substantial power supply built around a high-efficiency toroidal transformer — chosen for superior regulation and minimal radiated noise. It feeds an enormous storage bank of 30,000µF of filter capacitance per channel, totaling 150,000µF across all five channels. This reserve ensures stable, unwavering voltage under any power demand — from quiet dialogue to full-range, multi-channel peaks — keeping every channel composed and in control.

Built to Last

The GFA-5705 is as flawless in appearance as it is electronically. Its front panel is crafted from heavy-gauge anodized aluminum extrusion, while the chassis, top cover, and rear panel are heavy-gauge painted and baked steel. The result is a substantial, rack-ready amplifier that looks and feels like the serious piece of engineering it is.

Key Features

• 200W × 5 channels (8 ohms) / 300W × 5 channels (4 ohms) — all channels driven simultaneously
• 150,000µF total filter capacitance (30,000µF per channel) — massive power reserve for sustained, high-current delivery
• High-efficiency toroidal transformer — exceptional regulation, minimal noise and leakage inductance
• Drives low-impedance and reactive speaker loads with stability and control
• Damping factor >300 (20Hz–20kHz) — tight, authoritative bass across all channels
• Ultra-wide power bandwidth — 5Hz to 100kHz (−3dB)
• Ideal for home theater — purpose-built 5-channel design for surround sound systems
• Dual voltage compatible — 120VAC & 230VAC / 50–60Hz
• Heavy-gauge anodized aluminum & baked steel chassis — rack-compatible, built for long-term reliability

Technical Specifications

Frequently Asked Questions

What is the Adcom GFA-5705?

The Adcom GFA-5705 is a 5-channel Class A/B stereo power amplifier from Adcom, USA, rated at 200 watts per channel into 8 ohms and 300 watts per channel into 4 ohms with all channels driven simultaneously. It features a 150,000µF power supply, balanced XLR and unbalanced RCA inputs, and a damping factor exceeding 300, making it a purpose-built solution for high-performance home theater systems. The GFA-5705 is available at Vinyl Sound in Buffalo, NY as an authorized Adcom dealer.

How does the Adcom GFA-5705 compare to the Emotiva XPA-5 Gen3, NAD CI 9 x 60 DSP, and Rotel RMB-1585 MKII?

The Adcom GFA-5705 delivers more raw power per channel than all three competitors, rated at 200W into 8 ohms and 300W into 4 ohms with all channels driven. The Emotiva XPA-5 Gen3 offers 200W into 8 ohms but steps down significantly under load, while the NAD CI 9 x 60 DSP targets custom installation and distributed audio rather than dedicated home theater amplification. The Rotel RMB-1585 MKII delivers 200W x 5 but uses a combination of switching and linear power supply topology, whereas the GFA-5705 is a fully discrete linear Class A/B design with a massive toroidal transformer and 150,000µF of filter capacitance — providing a larger energy reserve for sustained, high-current demands. Shoppers in Buffalo and Western New York can audition and purchase the GFA-5705 at Vinyl Sound.

Can the Adcom GFA-5705 drive low-impedance or difficult loudspeakers?

Yes. The GFA-5705 was specifically engineered to drive loudspeakers with very low impedances and highly reactive loads at sustained high-power levels. Adcom used a computer model of a difficult reactive loudspeaker during development to verify performance into real-world loads — not just bench resistors — ensuring the amplifier delivers its full rated power where it counts. Its damping factor above 300 further ensures precise woofer control across all five channels simultaneously.

What is Class A/B amplifier topology and why does it matter?

Class A/B is a well-established amplifier design that combines the sonic benefits of Class A operation at low signal levels — where both output devices remain active simultaneously — with the greater efficiency of Class B at higher output levels. The result is an amplifier that offers low distortion and natural sound quality without the excessive heat and power consumption of pure Class A designs. In the GFA-5705, Class A/B topology is paired with a massive linear power supply, giving it both sonic refinement and the muscle to handle demanding 5-channel home theater loads continuously.

Does the Adcom GFA-5705 have balanced XLR inputs?

Yes. The GFA-5705 provides both balanced XLR and unbalanced RCA inputs on every channel, giving you full compatibility with virtually any AV processor or surround sound preamplifier. Balanced connections are particularly useful in home theater installations where longer cable runs between the processor and amplifier are common, as they reject induced noise and hum more effectively than single-ended RCA connections.

What AV processors pair well with the Adcom GFA-5705?

The GFA-5705 pairs naturally with any AV processor or surround preamp offering balanced XLR or unbalanced RCA outputs across five channels. Excellent pairing options include the Adcom GTP-600 preamplifier-processor, the NAD T 778 AV receiver used as a preamp-out source, and the Anthem AVM 90 processor for audiophile-grade home theater applications. With its 22,000-ohm input impedance and 1.8V RMS input sensitivity, the GFA-5705 is compatible with virtually all professional and consumer-grade surround processors available today.

Is the Adcom GFA-5705 rack-mountable?

The GFA-5705 features a standard 19-inch wide front panel, making it compatible with professional audio rack enclosures. At 10.75 inches tall and weighing 81 lbs., it requires a sturdy rack shelf rather than ear-mount brackets for proper support. Its dimensions of 10.75" x 19" x 19.75" should be confirmed against your rack depth before installation, as the 19.75-inch depth requires a deeper-than-standard rack.

Where can I buy the Adcom GFA-5705 in Buffalo or Western New York?

The Adcom GFA-5705 is available at Vinyl Sound, an authorized Adcom dealer located in Buffalo, NY. Vinyl Sound serves the greater Western New York and Buffalo metro area, offering expert guidance on home theater amplification, speaker pairing, and system integration. Visit vinylsound.com or stop in to experience the GFA-5705 firsthand.