RDL SF-PA50A – 50 W Mono Amplifier, 70/100 V, Plenum Rated
RDL SF-PA50A – 50 W Mono Amplifier, 70/100 V, Plenum Rated is backordered and will ship as soon as it is back in stock.
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RDL SF-PA50A – 50 W Mono Amplifier, 70/100 V, Plenum Rated
What is the RDL SF-PA50A?
The RDL SF-PA50A is a 50 W RMS Class D power amplifier that drives 70 V or 100 V constant voltage speaker lines from a single analog input. It is plenum rated per UL 2043, so it can be installed above ceilings in air-handling spaces. Remote VCA level control and power supply protection make it a dependable amplifier for distributed paging and background music.
How does it work?
An analog source connects to either the balanced mono terminal block input or the unbalanced stereo mini-jack, which sums left and right to mono. The installer sets gain with a rear-panel single-turn control and a dual-LED VU meter calibrated to 20 dB below full output power. An internal VCA sets the output level from an external 10 kΩ potentiometer, a 0 to 10 Vdc control voltage or RDL remote level controls, providing long-term noise-free adjustment. The high-efficiency Class D stage produces minimal heat, and thermal and output short-circuit protection are built in. During power-up, overload or overheating, a yellow MUTE LED lights and the output mutes. The amplifier monitors its power draw and limits current so the included 24 Vdc supply does not shut down, even under extreme feedback or square wave conditions, and a red OVERLOAD PROTECT LED flashes when this occurs. Frequency response is 50 Hz to 20 kHz (+0/-3 dB). The all-metal SYSFLEX enclosure supports free-standing, surface-mounted or rack-mounted operation, and the SF-UCB2 under counter bracket pair mounts it beneath a counter or table. RDL engineers and manufactures the SF-PA50A in the USA for continuous duty in demanding installations.
What are the key features?
- 50 W RMS at 70 V or 100 V — Drives distributed constant voltage speaker lines from one compact unit.
- Plenum rated per UL 2043 — Approved for installation in air-handling spaces above ceilings.
- Balanced or mini-jack input — Connect a balanced mono source or a stereo device summed to mono.
- Remote VCA level control — Use a 10 kΩ potentiometer, 0 to 10 Vdc or RDL remote controls.
- Power supply protection — Current limiting prevents supply shutdown during extreme feedback.
- Class D with full protection — Efficient operation with thermal and short-circuit protection.
Where is it typically used?
- Conference room
- Training room
- Multi-purpose room
- Commercial meeting space
- Government space
- House of worship
Technical Specifications
| Analog inputs (2) | Balanced terminal block or stereo unbalanced mini-jack (summed to mono) |
| Balanced input level | +4 dBu nominal; -10 dBu minimum; +25 dBu maximum |
| Unbalanced input level | -10 dBV nominal; -25 dBV minimum; +10 dBV maximum |
| Input impedance | > 10 kΩ balanced; > 5 kΩ unbalanced |
| Common mode rejection | > 60 dB (50 Hz to 120 Hz) |
| Amplifier output | 50 W RMS (70 V or 100 V) |
| Frequency response | +0/-3 dB (50 Hz to 20 kHz) |
| Indicators (5) | Power (blue), Amplifier muted (yellow), Overload Protect (red), dual-LED VU meter (2) |
| VCA | 0 to 10 Vdc control, detachable terminal block |
| Power requirement | 24 Vdc @ 2700 mA |
| Power supply (included) | 100 to 240 Vac, 50-60 Hz, IEC C14 inlet; 24 Vdc output |
| Plenum rating | UL 2043 |
| Operating environment | 32°F to 104°F (0°C to 40°C) maximum; 68°F (20°C) recommended |
| Dimensions | 1.7 x 5.83 x 6.45 in (4.32 x 14.8 x 16.38 cm) H x W x D |
| Shipping weight | 4.22 lb |
Frequently Asked Questions
Can the SF-PA50A be installed above a ceiling?
Yes. It is plenum rated per the UL 2043 standard.
Which speaker line voltages does it support?
It delivers 50 W RMS at 70 V or 100 V constant voltage.
Is the power supply included?
Yes. An external 100 to 240 Vac supply with 24 Vdc output is included.
Can I control volume from a wall plate?
Yes. The VCA accepts a 10 kΩ potentiometer, a 0 to 10 Vdc control or RDL remote level controls.
Can I connect a phone or laptop directly?
Yes. The stereo mini-jack input sums left and right to mono.
What warranty applies?
This product is covered by a 7-year RDL warranty. For warranty claims, RMAs or support, contact Creation Networks at (888) 230-3661 or sales@creationnetworks.net.
At Creation Networks, we do everything we can to create an excellent customer experience. This includes fast shipping and easy returns.
- Most in-stock orders placed Monday-Friday ship within 24-48 hours. General restrictions apply; please see our full shipping policy here.
- We offer a 30-day return policy from the delivery date on many products. Product restrictions apply. Restocking fees for the return of open-box items. Please see our full return policy here for more information.
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