Monitor Series Power Amplifier 2100 Power Envelope

A 2 x 50 watt (150 watt Bridged Mono) hi-fi stereo Power Amplifier in NAD's Monitor Series of hi-fi separates. With a high-voltage, high-current output stage enabling it to deliver well above its rated power to handle musical transients, and a 'soft clipping' circuit which gently limits the waveform voltage when the amplifier is driven beyond its rated power.

On the rear, Normal-In and Lab-in sockets for connection to a pre-amplifier, (Lab-in has a wideband frequency response), switches for Input (Normal or Lab), Soft Clipping (On/Off), Bridging (On/Off), and a Speakers Impedance switch (Normal 4Ω / Hi 8Ω), (the Hi setting can be used where one pair of speakers are connected and impedance is at least 8Ω, this re-optimizes the amplifier for maximum power). Some models have a switched and an unswitched AC outlet.

On the front, push button for Power, Speakers A, B, rotary controls for Left/Mono and Right Input Level, LED indicators for Power, Protection and Soft Clipping and a jack for headphones.

Specification
Stereo Mode
Continuous Average Power Output into
  8 ohm (Min, RMS power per channel
  20-20kHz both Channels Driven
  with no more than rated distortion) .......:  50 W
Rated Distortion  20Hz-20kHz ...............:  0.03%
Clipping Power (Maximum continuous....:  70 W
                        power per channel)
IHF Dynamic Headroom at 8 ohm .........:  +6dB
IHF Dynamic Power at 8 ohm ...............:  200 W
  (Short term power) at 4 ohm ...............:  250 W
                              at 2 ohm ...............:  330 W
Damping Factor at 50 Hz (Ref. 8 ohm) ..:  100
THD 20Hz-20kHz from 250mW to rated  :  <0.03%
Frequency Response, Lab input ...........:  3Hz - 100kHz, +0db -3dB
Signal to Noise Ratio A-weighted .........: 100db ref 1W, 117dB at rated power

Bridged (Monophonic) Mode
Continuous Average Power Output into
  8 ohm (Min, RMS power per channel
  20-20kHz both Channels Driven
  with no more than rated distortion) ......:  150 W
IHF Dynamic Headroom at 8 ohm .........:  +6dB
IHF Dynamic Power at 8 ohm (max.......:  500 W
 (Short term power)  at 4 ohm ...............:  660 W

Versions/Power Requirements
110 or 120 V AC 60Hz
220 or 240 V AC 50Hz

Made in Taiwan

Here you find 120 models, 118 with images and 25 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from NAD, New Acoustic Dimension; Ontario