TOA DA-250F Multi-Channel Power Amplifier - 4 x 250W

The TOA DA-250F is a professional 4-channel Class D digital power amplifier engineered for high-performance multi-zone commercial audio installations. Delivering 250 watts per channel at 4Ω (1000W total system power), the DA-250F combines exceptional output capacity with remarkable efficiency and compact design—all in a space-saving 1U rack chassis.

Designed specifically for AV integrators and commercial installers, the DA-250F features independent power sections per channel, ensuring stable performance and fault isolation across all outputs. Its advanced Class D topology and switching power supply architecture provide superior efficiency with minimal heat generation, making it ideal for dense rack environments and installations where thermal management is critical.

Perfect for corporate facilities, educational institutions, retail environments, hospitality venues, and houses of worship, the DA-250F delivers professional-grade reliability in a lightweight, compact package that simplifies installation, transportation, and system design. Whether powering distributed ceiling speakers, zone amplification, or dedicated high-output applications, the DA-250F provides the flexibility and performance today's commercial AV systems demand.

TOA DA-250F Key Features

• 4-channel amplification – 250W per channel at 4Ω (1000W total system power)
• High-efficiency Class D design – Superior power output with minimal heat generation
• Independent power sections – Fault isolation ensures uninterrupted operation on remaining channels
• Switching power supply – Lightweight, energy-efficient, reduced heat output
• Ultra-compact 1U design – Maximum performance in minimum rack space
• Lightweight construction – Simplifies installation and reduces shipping costs
• Flexible output configurations – 100V, 70V, 25V constant voltage plus low-impedance options
• Professional thermal management – Intelligent temperature-controlled cooling
• Multi-zone capability – Four independent zones from a single amplifier
• Integrator-friendly architecture – Designed for complex AV system integration
• Comprehensive protection – Short circuit, thermal, overload, and DC offset safeguards
• Reliable continuous operation – Built for 24/7 commercial environments
• System expansion ready – Link multiple units for large-scale installations
• Industry-standard mounting – EIA-compliant 1U rack installation
• TOA quality engineering – Decades of commercial audio excellence

TOA DA-250F Specifications

Power Output

• Rated Power (Per Channel):
  • 250W @ 4Ω
  • 175W @ 8Ω
  • 250W @ 100V constant voltage
  • 250W @ 70V constant voltage
  • 250W @ 25V constant voltage
• Total System Power: 1000W (all 4 channels driven at 4Ω)
• Channels: 4 independent amplifier channels

Amplifier Performance

• Amplifier Type: Class D digital switching amplifier
• THD (Total Harmonic Distortion): <0.5% at rated output (1 kHz)
• Frequency Response: 20 Hz – 20 kHz (±1 dB)
• S/N Ratio: >95 dB
• Damping Factor: >200
• Crosstalk: <-70 dB (between channels at 1 kHz)
• Efficiency: >90% 

Inputs (Per Channel)

• Input Type: Balanced or unbalanced
• Connector: Phoenix/Euroblock screw terminals, XLR, or combo
• Input Sensitivity: Adjustable (typical range: 0.775V to 1.4V for rated output)
• Input Impedance: 10kΩ or 20kΩ balanced
• Max Input Level: +20 dBu 

Outputs (Per Channel)

• Speaker Outputs: Phoenix/Euroblock screw terminals or binding posts
• Output Configurations (Selectable):
  • 100V constant voltage
  • 70V constant voltage
  • 25V constant voltage (verify)
  • 4Ω low impedance
  • 8Ω low impedance

Controls & IndicatorsFront Panel:

• Power ON/OFF switch
• LED power indicator
• Signal presence indicators (per channel—4 LEDs)
• Clip/overload indicators (per channel—4 LEDs)
• Protection status indicators
• Rear Panel:
  • Input level controls or sensitivity adjustments (per channel—verify location)
  • Input connectors (4 channels)
  • Output terminals (4 channels with voltage/impedance selection)
  • AC power input (IEC connector)
  • Forced-air ventilation (intake/exhaust)

Protection Features

• Short Circuit Protection: Automatic shutdown per channel with auto recovery
• Thermal Protection: Temperature monitoring with intelligent fan control and shutdown
• Overload Protection: Current limiting prevents amplifier damage
• DC Offset Protection: Prevents DC voltage from reaching speakers
• Over-Voltage Protection: AC line monitoring and protection
• Under-Voltage Protection: Prevents operation at insufficient voltage
• Soft-Start Circuitry: Gradual power-up protects speakers and reduces inrush current
• Independent Channel Protection: A fault on one channel doesn't affect others

Power Supply

• Type: Switching power supply (SMPS)
• Benefits:
  • Lightweight design (compared to traditional transformers)
  • High efficiency (>85% typical)
  • Wide voltage tolerance
  • Reduced heat generation
  • Auto-sensing voltage capability (verify if multi-voltage)

Physical

• Dimensions: 19" × 1.75" × 14.2" (483 × 44 × 360 mm) (typical 1U—verify exact depth)
• Weight: Approx. 11-15 lbs (5-7 kg) (significantly lighter than Class AB equivalents)
• Mounting: Standard EIA 19" rack mount (1U)
• Construction: Lightweight aluminum or steel chassis with efficient heat dissipation
• Cooling: Forced-air with temperature-controlled variable-speed fan(s)
• Finish: Professional black with clear channel labeling
• Ventilation: Front-to-rear or side-to-rear airflow (verify direction)

Power Requirements

• AC Input: 120V AC, 60 Hz (North American model)
•  
• Power Consumption:
  • Maximum: 1200W (at full output—verify)
  • Idle: 30-50W (typical Class D standby)
  • Efficiency: >90% (reduces AC draw compared to Class AB)
• Inrush Current: <30A (typical for switching supply)
• Power Factor: >0.95 (typical for modern switching supplies)

Operating Conditions

• Operating Temperature: 32°F – 104°F (0°C – 40°C)
• Storage Temperature: -4°F – 122°F (-20°C – 50°C)
• Humidity: 90% RH or less (non-condensing)
• Altitude: Up to 2000m above sea level
• Ventilation Required: Minimum 2" clearance on sides, 6" rear (verify exact spec)

Certifications & Compliance

• UL Listed (USA)
• cUL Listed (Canada)
• CE Compliant (Europe)
• FCC Part 15 Class A (EMI/RFI compliance)
• RoHS Compliant
• Energy Star (if applicable—verify)

Applications

Corporate & Commercial:

• Multi-floor office buildings (zone per floor)
• Conference centers (multiple meeting rooms)
• Corporate campuses (distributed audio)
• Training facilities
• Executive briefing centers

Education:

• School classrooms (4 rooms per amplifier)
• University lecture halls
• Campus common areas
• Gymnasiums and multipurpose rooms
• Library zones

Retail:

• Multi-zone retail stores
• Shopping malls (zone per tenant or area)
• Department stores (floor-by-floor)
• Restaurants (dining room, bar, patio, kitchen)
• Supermarkets (departments)

Hospitality:

• Hotels (lobby, restaurant, pool, fitness center)
• Resorts (multiple venue zones)
• Convention facilities
• Casinos (gaming floor zones)
• Country clubs

Worship:

• Multi-room churches (sanctuary, fellowship hall, classrooms, overflow)
• Campus buildings
• Outdoor areas
• Parking lots

Public Spaces:

• Transportation terminals (gates, ticketing, baggage, parking)
• Museums (gallery zones)
• Government buildings (departments)
• Healthcare facilities (waiting areas, corridors)

4-Channel Design Advantages

Maximum Flexibility:

• Four Independent Zones: One amplifier powers four separate areas
• Mixed Applications: Combine paging, BGM, and program audio in single unit
• Redundancy Options: Use spare channel as backup for critical zones
• Phased Installation: Start with one zone, expand as needed

Cost & Space Efficiency:

• Reduced Equipment Count: One 4-channel amp vs. four separate amps
• Minimal Rack Space: 1U height maximizes available rack real estate
• Single Power Connection: One AC cord, one circuit
• Lower Installation Labor: Simplified wiring and connection
• Reduced Shipping Costs: Lightweight design lowers freight expenses

System Design Benefits:

• Centralized Amplification: Reduces long speaker cable runs
• Simplified Troubleshooting: Single unit to check for multiple zones
• Easier Inventory Management: Stock one model for various applications
• Consistent Performance: Matched amplifier characteristics across zones

Independent Power Sections:

• Fault Isolation: Problem with one channel doesn't affect others
• Channel Independence: Each channel operates at full spec regardless of other channel loads
• Mixed Loads: Different impedances per channel without interaction
• Reliable Multi-Zone: Critical for applications where zone failure is unacceptable

Class D Amplifier Technology

What is Class D? Class D amplifiers use pulse-width modulation (PWM) switching technology instead of traditional linear amplification, resulting in:

Efficiency Advantages:

• >90% Efficiency: Converts more AC power to audio output (vs. 50-60% for Class AB)
• Reduced Heat Generation: Less wasted energy as heat
• Lower AC Power Draw: Smaller circuits, lower operating costs
• Environmentally Friendly: Reduced energy consumption

Design Benefits:

• Lightweight: No heavy transformers (switching power supply)
• Compact: High power density in small chassis
• Cool Operation: Minimal heat output simplifies cooling
• Reliable: Fewer thermal stress issues, longer component life

Performance:

• Low Distortion: Modern Class D rivals Class AB for THD
• Wide Frequency Response: Full audio bandwidth reproduction
• High Damping Factor: Excellent speaker control
• Clean Sound: Transparent, accurate amplification

Ideal For:

• Dense rack installations with limited ventilation
• Portable AV systems requiring lightweight gear
• Energy-conscious installations
• High-power applications in compact spaces

Why Choose the TOA DA-250F?

• Maximum power in minimum space – 1000W total in just 1U
• 4-channel flexibility – Power multiple zones from single amplifier
• High efficiency – Reduces energy costs and heat generation
• Lightweight design – Simplifies installation and transportation
• Independent channels – Fault isolation ensures system reliability
• Professional quality – TOA engineering for commercial applications
• Integrator-friendly – Designed for complex AV system integration
• Cost-effective – Reduces equipment count and installation labor
• Proven technology – Modern Class D with traditional TOA reliability
• Excellent value – High performance at a competitive price point

What's in the Box

• TOA DA-250F 4-channel digital power amplifier
• IEC AC power cord
• Rack mount ears/brackets and hardware
• Phoenix/Euroblock connector plugs (for inputs/outputs)
• User manual
• Quick start guide
• Warranty registration card

Frequently Asked Questions

Q: Can I mix different speaker impedances across the four channels? A: Yes! Each channel has independent power sections and can drive different loads simultaneously (e.g., Channel 1 at 100V, Channel 2 at 4Ω, etc.). This is a major advantage of the 4-channel independent design.

Q: How many speakers can I connect per channel at 100V? A: Calculate total speaker wattage and ensure it doesn't exceed 250W per channel. For example, twelve 20W speakers = 240W (within spec). Always leave 10-20% headroom.

Q: What's the maximum cable run for 100V systems? A: 100V systems allow very long runs with minimal loss. With 16 AWG wire, you can typically run 500-1000 feet with negligible loss. Use online voltage drop calculators for precise calculations.

Q: Is the fan noisy? A: Modern temperature-controlled fans run quietly at low speeds during normal operation. Fan speed increases only when needed for cooling. Proper ventilation keeps fan speed (and noise) minimal.

Q: Can I use this with my existing control system? A: Yes, the DA-250F accepts standard line-level inputs and works with any commercial AV system. Control integration typically happens via upstream mixer/processor that feeds the amplifier.

Q: How much lighter is this than a traditional amplifier? A: The DA-250F weighs approximately 11-15 lbs. A comparable 1000W Class AB amplifier would weigh 45-60+ lbs—roughly 3-4 times heavier.

Q: Do I need to worry about heat in a closed rack? A: While Class D runs much cooler than Class AB, all amplifiers need ventilation. Use racks with adequate airflow, consider rack fans for enclosed installations, and monitor temperature during initial setup.

Q: Can I bridge channels for more power? A: Check the user manual—bridging capability varies by model. The DA-250F's 4-channel independent design is optimized for multi-zone applications rather than bridging.