ADCOM - GFA-5705 - 5-Channel - Power Amplifier

ADCOM - GFA-5705 - 5-Channel Power Amplifier
The ADCOM GFA-5705 is a five-channel power amplifier designed for home theater systems and high-output multichannel music playback. Built to drive a broad range of loudspeakers, including low-impedance and reactive loads, it delivers the power needed for front, center, and surround channels from a single chassis.
The GFA-5705 is rated at 200 watts per channel into 8 ohms and 300 watts per channel into 4 ohms with all channels driven. Its power supply uses a 1.7kVA shielded toroidal transformer and 150,000µF of total filter capacitance, giving the amplifier strong reserve capacity for dynamic passages. Balanced XLR and unbalanced RCA inputs are provided for all five channels, while 24K gold 5-way speaker terminals support secure connections to full-range speakers or home theater speaker arrays.
ADCOM equips the GFA-5705 with 15 matched pairs of TO-3 metal-cased bipolar output transistors, extra-large heatsinks, protection circuitry, and system-control features such as auto signal sensing and 5V-12V trigger input. Its heavy-gauge aluminum and steel chassis construction gives it the physical strength expected from a high-current multichannel amplifier. For users building a serious surround sound system, the GFA-5705 provides classic ADCOM power in a practical five-channel format.
FEATURES:
- Five-channel power amplifier for home theater and music systems
- 200 watts per channel into 8 ohms
- 300 watts per channel into 4 ohms
- Balanced XLR and unbalanced RCA inputs for each channel
- Drives low-impedance and reactive loudspeaker loads
- 150,000µF total filter capacitance supports reserve power
- 1.7kVA shielded toroidal transformer supports stable current delivery
- 15 matched pairs of TO-3 bipolar output transistors
- Auto signal sensing and 5V-12V trigger support system automation
- 24K gold 5-way speaker terminals support secure connections
SPECIFICATIONS:
| Product Type | 5-Channel Power Amplifier |
| Model | GFA-5705 |
| Power Output - 8 ohms | 200Wpc Continuous, 20Hz-20kHz, All Channels Driven, <0.05% THD |
| Power Output - 4 ohms | 300Wpc Continuous, 20Hz-20kHz, All Channels Driven, <0.07% THD |
| Frequency Response | 10Hz-20kHz, +0 / -0.25dB at 1W into 8 ohms |
| Power Bandwidth | 5Hz-100kHz, -3dB |
| Dynamic Headroom | 1.2dB into 4 ohms |
| Signal-to-Noise Ratio | ≥106dB, A-Weighted, 200W into 8 ohms |
| Gain | 27dB |
| Input Impedance | 22,000 ohms |
| Input Sensitivity | 1.8V RMS for 200W into 8 ohms |
| Damping Factor | >300, 20Hz-20kHz |
| THD + Noise - 200W into 8 ohms | 0.030% at 20Hz; 0.008% at 1kHz; 0.030% at 10kHz; 0.050% at 20kHz |
| THD + Noise - 300W into 4 ohms | 0.05% at 20Hz; 0.01% at 1kHz; 0.05% at 10kHz; 0.07% at 20kHz |
| IM Distortion - 8 ohms | ≤0.03%, 1W to 200W |
| IM Distortion - 4 ohms | ≤0.05%, 1W to 300W |
| Inputs | 5 x Balanced XLR, 5 x Unbalanced RCA |
| Speaker Terminals | 24K Gold 5-Way Speaker Terminals |
| Power Supply Capacitance | 150,000µF Total Filter Capacitance |
| Transformer | 1.7kVA Shielded Toroidal Power Transformer |
| Output Devices | 15 Matched Pairs of TO-3 Metal-Cased Bipolar Output Transistors |
| Power Modes | Manual, Auto Signal Sensing, 5V-12V DC Trigger |
| Trigger Output | 12V DC, 100mA, 3.5mm Jack |
| Protection | Over-Current, Over-Temperature, DC Servo, DC Current, Speaker Relay Protection |
| Rise Time | 2.3µs, 5kHz, 120V Peak-to-Peak Square Wave, 20% to 80% |
| Power Consumption | 120VA Quiescent; 1350VA at 200W into 8 ohms; 1800VA Maximum |
| Power Requirements | 120VAC / 60Hz; 230VAC / 50Hz |
| AC Line Fuse | T20A / 120V Area; T12A / 230V Area |
| Chassis Dimensions (H x W x D) | 8.7" x 17.0" x 17.7" (222mm x 432mm x 450mm) |
| Packing Dimensions (H x W x D) | 10.7" x 19.0 " x 19.7 " (275mm x 480mm x 565mm) |
| Weight | 81.0 lbs (37kg) |
| Shipping Weight | 90.0 lbs (41kg) |


