• Intro

    REF501S Stereo Amplifier

    The REF501S stereo amplifier, solidly built all-aluminum compact chassis, delivers dynamic, accurate hi resolution sound at 250 Watts with incredible speed and control.

    • Max Power Output 250W @1% THD per Channel
    • Minimum Load: 2 ohms per Channel
    • Peak Output Current: 17.5 Amps per Channel
    • Balanced Input Impedance: 95 Kohms
    • Voltage Gain 27dB
  • Features

    REF501S Stereo Amplifier Features


    Impedance Optimized Input Stage uses selected precision resistors in a balanced high Common Mode Rejection, low output impedance driver that is critical to the amplifier's performance, ensuring that the refined dynamic qualities of the recording are preserved.

    DC Signal Path

    The REF501S is DC coupled with no coupling capacitor in the signal path. This optimizes the audio signal quality and maximizes both micro and macro dynamic performance. The amplifier will protect itself and your speakers if excess DC is detected with very fast shut-off.

    At the Core

    High speed ultra-efficient switch mode amplification delivers literally unheard-of levels of performance using an innovative 5th order loop filter. This technology provides extremely low noise and distortion performance over the entire audio bandwidth, allowing the musical message to come through unchanged and with remarkable purity.

    Why Class D?

    Well-designed Class D switching supplies generally sound more open through the midrange with better Bass control. Note that 250W is 23.9dBw which means that it will drive an 85dB speaker to 108dB with 111dB peaks, theoretically. In a large room with the volume control 10dB below max we’re measuring about 25W of continuous power. This is loud! Most power concerns are more about control rather than how much real power is delivered. This gives further advantage to Class D and switching power supplies as their efficiency is high even at lower power outputs helping them sound ‘bigger’.

    WBT NextGen Speaker Connectors

    The WBT NextGen connectors provide the best possible connection from the amplifier to the speaker cables. We choose them because they impart minimal sonic signature to the sound, remaining open and grain-free up throughout the audio frequency band.

  • Specs

    REF501S Stereo Amplifier Specifications

    Power Output 1% THD: 250W per channel
    Minimum Load: 2 ohms per channel
    Peak Output Current: 17.5 amperes per channel
    Frequency Response: +/-3 dB 0Hz-50KHz, all loads
    THD+N: 0.003% 1W, 1KHz, 4 ohms
    IMD (CCIF): 0.0003%, 1W, 14:15KHz, 4 ohms
    Output noise: 35uVRMS A-weighted 10Hz-20KHz
    Voltage gain: 27dB
    Damping factor: >1000
    Output Impedance at 100Hz: <8 milliohms
    Dynamic Range: 121dB
    Input Voltage for Max Output: 1.4Vrms
    Input connections: Single-ended RCA or balanced XLR
    RCA input impedance: 47Kohms
    Balanced input impedance: 95Kohms
    Output connections: 2-sets WBT Nextgen 5-way binding posts
    Power On usage: 12W
    Power Off usage: 0.0W
    Internally Set Operating Voltages: 100-120VAC or 230-240VAC 50/60 Hz
    Size: 8.5 x 3.5 x 12[inches], 216 x 88 x 305[mm] (WxHxD)
    Weight: 12 lbs, 5.5 Kg

    Features and specifications are subject to improvements and changes without prior notice.

  • Reviews

    REF501S Stereo Amplifier Reviews