Topmodel Technics SH-8065,
2x-mono equalizer. One of the best graphic
equalizers. Multi-functional by per octave three frequencies
(11 octaves) with a cut/boost effect of 12 dB each band, 33 bands in total every channel. That works very precise: you must "administrate" any from each frequencybands to remember the settings. That is right: the set comes with prepared "board-with-sliderholes" from Technics, so you can. Hold that board at the front of the case and note the settings!
Next: a by-pass switch, immediately switching from the + or - 3 dB to the + or - 12 dB range, immediately switching from cut to boost according to the setting without altering the sliders. In short: wide frequency-tunings with the accuracy of three band per octave.
You also can use the equalizer as a hard cutting/boosting 48 dB bandfilter. To do so you you chain the channels in series and to set all 66 sliders, for boosting a specific frequency, to minus 12 dB. In fact the whole signal is attenuanted 24 dB
(-12 dB channel one, plus -12dB channel two), but after pulling-up the slider from that specific frequency (or more frequencies) to + 12 dB, again for both channels, the result is a boost of + 48 dB against the rest. In that way you have for each band two identical filters, chained and 66 in total. An example: you now can boost a voice (about 2 - 2,5 kHz.) above music to make it audible by far.
See the righthand diagram.
Indeed effective filtering without self-oscillating like the VCF from a synthesizer.
Colour: silver, well documentated, with sliderholes boards, undamaged!