The SB620 is one of my favourites - great condition  -  fantastic power delivery and dynamics
A pair of the precision greats from the era of brushed aluminium 
 
Specifications
Power output: 62 watts per channel into 8Ω (stereo)
Frequency response: 10Hz to 50kHz
Total harmonic distortion: 0.2%
Input sensitivity: 2mV (MM), 150mV (line)
Signal to noise ratio: 73dB (MM), 90dB (line)
Output: 150mV (line), 30mV (DIN), 1V (Pre out)
Speaker load impedance: 4Ω to 16Ω
Dimensions: 450 x 148 x 375mm
Weight: 14kg