(Pair) Differential Reference™ Monoblock Power Amplifiers with Switchable Class A or Class A/B Operation
Features offered by the XPA-1L include: • Fully balanced, Differential Reference™ design with quad differential input stage and cross-coupled active current sources. • Switchable Class A and Class A/B operating modes. • Massive, high current toroidal power supply. • Advanced microprocessor operating system which protects the amplifier from all fault conditions. • Discrete differential front end, no integrated circuits. • Balanced and unbalanced inputs. • Trigger input and output. • Front panel status LED with switchable stealth mode. • Fully protected from all fault conditions. • Machined, gold plated, unbalanced RCA input connector. • Heavy duty, gold plated, clear jacketed audiophile speaker binding posts. • Soft-touch power switch. • Solid milled aluminum faceplate. • Automatic 120/230 AC voltage detection and switching. • IEC power inlet. • Laser etched serial number badge. • Transferrable warranty. (These units have warranty until September 24, 2018).
Topology: Fully balanced, fully discrete, quad differential, high current, short signal path,
with user switchable Class A or Class A/B operation.
Number of Channels: 1
Power Output (rated power; THD < 0.1%): 250 watts into 8 Ohms; Class A/B operation. 500 watts into 4 Ohms; Class A/B operation. 35 watts Class A, transitioning to 250 watts Class A/B into 8 ohms; Class A operation. (Note: In Class A mode, the XPA-1L operates in pure Class A mode at all power levels up to
35 watts, at which point it automatically transitions into Class A/B mode).
Rated Power Bandwidth (at rated power; 8 Ohm load): 20 Hz to 20 kHz + / - 0.15 dB.
Minimum Recommended Load Impedance: 4 Ohms (which equals one 4 Ohm load or two paralleled 8 Ohm loads).
Frequency Response: 10 Hz to 80 kHz (+ 0 / - 2 dB).
THD + noise: < 0.005%
Signal to Noise Ratio (8 Ohm load): > 90 dB at 1 watt (A-weighted). > 116 dB at rated power (A-weighted).
Damping Factor (8 Ohm load): > 500
Speaker Output Connections: Audiophile grade five-way binding posts, gold plated with clear insulator, 1 pair.
Power Supply: 90,000 uF of storage capacitance. 450 VA heavy duty toroidal transformer.
Input Sensitivity (for rated power; 8 Ohm load): 1800 mV.
Gain: 29 dB.
Input Connections: Unbalanced (RCA); balanced (XLR); switchable.
Input Impedance: 50k ohms.
Trigger: Trigger Input: 5 - 20 V (AC or DC); <10 mA input current required. Trigger Output: 12 VDC; can drive any load up to 100 mA.
Power Requirements: 115 VAC or 230 VAC +/- 10% @ 50 / 60 Hz (automatically detected and switched).
Front Panel Controls and Indicators: Standby; push button (halo ring changes color to indicate Standby or On). Status LED; illuminates blue for normal operation, flashes red during power-up or when a
fault occurs (may be disabled by rear panel Status LED switch).
Rear Panel Controls: AC Power switch; rocker switch (switches AC mains power). Status LED switch; small slide switch (disables front panel Status LED). Input selector; toggle switch (selects between balanced and unbalanced inputs).
Protection: The XPA-1L is protected against excessive operating temperature, shorted speaker
connections, ground faults, and other common fault conditions.
Dimensions: 17” wide x 3.875” high x 19” deep (includes feet and binding posts). 23” x 24.5” x 8.75” (boxed).
Weight: 35 pounds unboxed (45 pounds boxed).