ADCOM - GFA-555SE - Power Amplifier
The ADCOM GFA-555se is a high-current stereo power amplifier that revives one of ADCOM’s most recognized amplifier platforms with updated internal construction and modern compliance improvements. Based on the classic GFA-555 design, the GFA-555se is built for listeners who want strong output, stable speaker control, and the straightforward reliability that made the original model so respected.
The GFA-555se delivers 200 watts per channel into 8 ohms, 300 watts per channel into 4 ohms, and 600 watts in bridged mono operation into 8 ohms. It includes balanced XLR and unbalanced RCA inputs, high-quality gold-plated RCA jacks, gold-plated 5-way binding posts, independent channel power supplies, and 60,000µF of power supply filter capacitance. A custom toroidal transformer helps provide the current reserve needed for demanding loudspeakers and dynamic music playback.
ADCOM’s upgraded SE design uses precision-matched devices, fewer gain stages, large independent heatsinks, and independent distortion LEDs for each channel. Its high damping factor, wide power bandwidth, and low distortion performance make it a strong match for full-range speakers, large two-channel systems, and bridged mono applications. The GFA-555se offers classic ADCOM power with modern balanced connectivity and a durable chassis built for long-term system use.
FEATURES:
- High-current stereo power amplifier based on the classic GFA-555 design
- 200 watts per channel into 8 ohms
- 300 watts per channel into 4 ohms
- 600 watts bridged mono into 8 ohms
- Balanced XLR and unbalanced RCA inputs
- Custom toroidal transformer supports strong peak current delivery
- 60,000µF power supply filter capacitance provides reserve capacity
- Independent power supplies support each amplifier channel
- Independent distortion LEDs monitor each channel
- Gold-plated 5-way binding posts support secure speaker connection
SPECIFICATIONS:
| Product Type | High-Current Power Amplifier |
| Model | GFA-555se |
| Channels | 2-Channel Stereo / Bridged Mono |
| Power Output - 8 ohms | 200Wpc Continuous, 20Hz-20kHz, Both Channels Driven, <0.04% THD |
| Power Output - 4 ohms | 300Wpc Continuous, 20Hz-20kHz, Both Channels Driven, <0.04% THD |
| Power Output - Bridged Mono | 600W into 8 ohms, 20Hz-20kHz, <0.09% THD |
| Frequency Response | 10Hz-20kHz, +0 / -0.25dB at 1W into 8 ohms |
| Power Bandwidth | 10Hz-100kHz, -3dB |
| Dynamic Headroom | 2.5dB into 4 ohms, with supplemental cooling |
| Signal-to-Noise Ratio | ≥110dB, A-Weighted, 200W into 8 ohms |
| Gain | 27dB |
| Input Impedance | 10k ohms Balanced, 100k ohms Unbalanced |
| Input Sensitivity | 1.75V RMS for 200W into 8 ohms; 130mV RMS for 1W into 8 ohms |
| Damping Factor | ≥900, 20Hz-20kHz |
| IM Distortion - 8 ohms | ≤0.009%, 1W to 200W |
| IM Distortion - 4 ohms | ≤0.009%, 1W to 300W |
| THD + Noise - 200W into 8 ohms | 0.004% at 20Hz; 0.003% at 1kHz; 0.006% at 10kHz; 0.010% at 20kHz |
| THD + Noise - 300W into 4 ohms | 0.005% at 20Hz; 0.004% at 1kHz; 0.015% at 10kHz; 0.025% at 20kHz |
| Rise Time | 2.3µS, 5kHz, 120V Peak-to-Peak Square Wave, 20% to 80% |
| Power Consumption | 72VA Quiescent; 1500VA Maximum |
| Power Requirements | 120VAC, 50/60Hz; 230V Available by Special Order |
| Chassis Dimensions (H x W x D) | 6.9" x 12.1" x 16.9" (176mm x 308mm x 430mm) |
| Maximum Dimensions (H x W x D) | 7.5" x 12.5" x 17.0" (191mm x 318mm x 432mm) |
| Weight | 36 lbs (16.3kg) |
| Shipping Weight | 40 lbs (18.1kg) |
