SWR SM-500 Tube Preamp/Solid State Power Amp

Pre-owned SWR SM-500 Tube Preamp/Solid State Power Amp.

The SM-500 Professional Bass Amplifier provides the power, performance, flexibility and portability required by the professional bassist for every style of playing and nearly every playing situation.
To design an amplifier that would cover “all of the basses,” SWR had to use almost every imaginable type of electronic component available. This added up to an all TUBE preamp section, a limiter circuit utilizing Field Effect Transistors (“FETs”), tone and equalizer controls utilizing integrated circuits, and two individual power amps employing discrete, solid state devices.
The power amplifiers in the SM-500 can be used individually to provide full stereo capabilities, each delivering 250 watts into individual 4 ohm speaker enclosures. In the event that more power is required, the amplifiers can be bridged for 400 Watts @ 8 ohms or 550 watts @ 4 ohms. The power amps are cooled by a thermostatically controlled fan and the chassis is vented on its rear and right side.
The SM-500 also boasts a studio-oriented “side chain" effects loop allowing you to use an effects unit while maintaining the constant clarity and naturalness of the instrument. The SM-500’s Tuner Out jack is also on a side chain. Remember when you had to unplug your bass from your amp and hook into your tuner and frantically tune up between songs? Or install the tuner between your instrument and amp, thus degrading sound quality? Those times are history!
The SM-500 is housed in an all aluminum chassis for light weight and lasting beauty and weighs just 20 pounds. It is easily carried by the heavy-duty, chrome rack handles secured to the front panel.
The tube employed in the preamp section of the SM-500 is a specially selected 12AX7 and should not require replacement for one to three years.
FRONT PANEL FEATURES:
• Dual independent input jacks compatible for both active and passive instruments
• Gain Control with LED peak clipping indicator
• Variable Limiter Control
• Aural Enhancer Control
• Bass Control ±15dB cut/boost (shelving point: 80Hz)
• Treble Control ±15dB cut/boost (shelving point: 2kHz)
• Transparency Control ±15dB cut/boost (shelving point: 5kHz)
• Variable Graphic Equalizer with ±15dB cut/boost
• Band One: 31Hz to 160Hz
• Band Two: 80Hz to 320Hz
• Band Three: 200Hz to 800Hz
• Band Four: 400Hz to 1.6kHz
• Effects Blend Control
• Dual Concentric (Stereo) Master Volume Control
• Speaker On/Off Switch
• Power On/Off Switch
REAR PANEL FEATURES:
• Balanced XLR Output with select switch for Line or Direct Mode
• XLR ground lift & pad control
• Power Amp Assign Switch (selects Bridge or Stereo mode)
• Side Chain Effects Loop
• Tuner Output
• Two 1/4" jacks per side for Left and Right Stereo Output
• One Speakon® output jack per side for Left and Right Stereo Output
• One Speakon® output jack for Mono/Bridge operation
• (2) Speaker fuses: 3AG, 8 amp, fast-blo
• (1) Line Fuse: 3AG, 7 amp, slo-blo
• AC power cord receptacle
SPECIFICATIONS:
POWER (minimum): Bridge/Mono Mode
500 Watts @ 4 Ohms
400 Watts @ 8 Ohms
250 Watts @ 16 Ohms (minimum load = 4 Ohms) Stereo Mode (per side)
300 watts @ 2 Ohms
250 watts @ 4 Ohms
150 watts @ 8 Ohms (minimum load = 2 Ohms) FREQUENCY RESPONSE (power amplifier): 10Hz to 40kHz SENSITIVITY (full output under clipping, 8 ohms load, 100Hz):
Passive Input Jack: 38 millivolts
Active Input Jack: 155 millivolts
Power Amplifier (Effects Return Jack “in”): .5 volts
INPUT IMPEDANCE:
Passive/Active Input: 800kohms
Active Input: 60kohms
Effects Return: 27kohms
OUTPUT IMPEDANCE:
Effects Send: 100 ohms
Tuner Output: 100 ohms
XLR Balanced Out: 750 ohms
SIGNAL TO NOISE RATIO: –72 dB (<10 millivolts typical) EQUIVALENT INPUT NOISE: 9 microvolts SIZE (measured from the rack ears back): 19" W x 3.5" H x 13.375" D (82.6 x 8.9 x 39.73 mm) WEIGHT: 20 lbs. (9.07 kg)