Revox B-252 Preamp
The ReVox B252 was introduced in 1982 with a production run until 1990 and an original selling price of $1,750.00. It was the dedicated preamplifier of the famed 200 series line of ReVox components that is still very highly regarded today. The B252 looks pretty much identical to the B251 integrated amplifier; it is a direct spin-off of that component sans the amplifier section. This dedicated preamp gave consumers the freedom to choose any amplifier(S) of their liking, and further contributed to the purity of the sound signal. The B252 was way ahead of its time when produced, serving as the perfect model of new technology and time proven circuitry integrated appropriately. The controls on the lower part of the front panel-which include tone, balance, and the recording source selectors-are treated as ancillary and protected from casual use by a clear plastic pop-off cover. The "regular" operating controls, ranged along the top edge of the panel, include a Standby/on switch ,input selectors, tone defeat, a 20-dB output attenuator switch, and volume. TUNER: 160 mV ... 2.3V,: nominally 500 mV/47 kOhms AUX: 160 mV ... 2.3 V, nominally 500mV/47 kOhms C-DISC: 160 mV ... 2.3V, nominally 500mV/47 kOhms TAPE 1: 160 mV ... 2.3 V, nominally 500mV/47 kOhms TAPE 2: 160 mV .,. 2.3 V, nominally 500mV/47 kOhms EXT, FILTER PHONO MC: nominally 700mV/47 kOhms : 100 VV ,.. 1.2 mV, nominally 300 ~V/100 Ohms PHONO MM: 1.6 mV ... 23 mV, nominally 5 mV/47 kOhms/ 68 pF ... 400 pF Outputs Level/Permissible Load TAPE 1: 100 mV ... 1.7 V, nominally 500m~/>10 kOhms TAPE 2: 100 mV ... 1.7 V, nominally 500 mV/>10 kOhms TAPE COPY: nominally 500 mV/>10 kOhms EXT. FILTER: nominally 700mV/>10 kOhms HEADPHONES(2 x): 15V max. (at 100W/4 Ohms), adjustable in 4 steps, f+4,0, -4, -8 Output at Clipping: High Output: 15.2V Low Output: 3.0V Output Impedance: Main: 600 Ohms Tone Controls Bass: 30 Hz/+12 dB ... -12 dB Treble: 15 kHz/+7 dB ... -7 dB Subsonic filter 18 Hz,18 dB/Octave(assignable to each program source) Signal- to-noise ratio, linear: (High level inputs, referred to 500 mV, 10 kOhms termination): 96dB relative to nominal power output 80dB at 50 mW (Phono MM input, referred to 5mV,1 kOhm Termination) 75 dB relative to nominal power output 75dB at 50 mW equivalent noise voltage at the input -124dBV Crosstalk between Inputs (at 10 kHz) 90 dB Channel separation: (at 1 kHz) 94dB Frequency Response 20 Hz ... 20 kHz: +0/-0.2 dB Phono RIAA equalization: (4 times constant) +/-0.3dB Total harmonic distortion: (at 10 kHz) less than 0.01% Rise Time 2 us with 4 0hms load Dimensions 17 3/4" 6" H x 14" D Weight 17lbs
