The SP-20A is a stereo power amplifier housed in a half-rack chassis that delivers 20 watt per channel into either 4 ohms or 8 ohms. It is ideal for recording studio applications, where it can be used to drive small reference speakers, or as a headphone driver for the HR-2 headphone remote stations, while doubling as the tape playback amplifier in the tracking room.
The SP-20A may be operated in any of three modes as selected by a rear-panel switch: normal stereo, two channel mono, or single channel (bridged) mono. The latter mode allows a power output of 40 watts provided the load is 8 or more ohms. Output is available through either of two connectors. Standard banana jack binding posts for speakers, or through a male XLR connector. The latter allows the unit to become the headphone driver.
The amplifier has an input level control on the left side of the front panel. A pair of yellow LEDs, one for each channel -- light up whenever signal is present. Another pair of red LED's warns of any overload condition present in either channel. The SP-20A is fully protected against thermal overload, and it can withstand a short circuit on any or all outputs for an indefinite time without damage.
Features
- Stereo power amplifier ideal for small speakers or headphone system
- Toroidal transformer provides for ultra-quiet performance
- Overload and signal-present LED's for each channel
- Bridged mono, two channel mono and stereo operation
- Speaker on-off switch
- Front panel headphone jack with volume control
- Convection cooling system dissipates heat through the heat sinks and chassis for optimal cooling and maintenance-free operation
Specifications
- Power Rating
- Stereo @ 4 ohms: 20 watts per channel
- Stereo @ 8 ohms: 20 watts per channel
- Bridged @ 8 ohms: 40 watts
- Damping Factor: 120 at 1kHz
- Input Sensitivity: -1.9dBu (625 mV) required for full output into 8 ohms
- Input Impedance: 20k ohm
- Gain: Not specified by manufacturer
- Frequency Response: 20Hz to 20kHz, 1 watt output, +0, -1dB
- Signal-to-Noise Ratio: Not specified by manufacturer
- Total Harmonic Distortion (THD): 0.01% THD at full rated power at 1kHz; 0.05% THD 20Hz to 20kHz
- Input Connections: 1 x XLR female per channel
- Output Connectors
- Dual banana/binding post terminals
- 1 x XLR male satelite/remote
- 1 x Headphone
- Controls Front Panel
- 1 x Rotary input level control
- 1 x Rotary headphone volume control
- 1 x Speaker on/off switch
- Controls (Rear): Ground lift switch
- Indicators: 1 x Signal, 1 x Overload LED indicators per channel
- Cooling: Convection
- Power Consumption: 130 watts
- Dimensions: 8 7/16" x 8 1/4" x 1 3/4"
- Weight: 6 lbs
- Specialties: Ground lift switch