Technics SU-10000 (c. 1973)
The SU-10000 was Technics' flagship stereo control amplifier of the early 1970s. The period record calls it the centerpiece of the "10000 series," developed without compromise and priced at ¥450,000 around 1973. "Control amplifier" means what we'd now call a preamplifier: a full-featured phono/tone/tape/mic switching and control stage, with no power output section.
The phono stage is the big part of the story. The equalizer amplifier is a four-stage direct-coupled circuit - three differential stages feeding an emitter follower. The first stage uses a specially selected low-noise PNP transistor, and the last stage runs on a 162-volt supply. That supply is why it can accept phono inputs up to 450mV on the low setting and 1.35V on the high setting without overload. Both Phono 1 and Phono 2 let you switch input impedance among 30k, 50k, and 100k ohms and sensitivity between 1mV and 3mV. A rear-panel switch determines whether the front panel shows the selected impedance. RIAA accuracy is quoted at within ±0.3 dB.
Volume is a 22-step switch-type attenuator instead of a conventional pot. It runs from 0 dB to infinity, adjustable in 2 dB steps down to -34 dB, with a separate -20 dB attenuator extending that fine control to -54 dB. The goal was to avoid the signal-to-noise degradation typical of a carbon volume control at low settings. The tone control section also uses a differential amplifier, adjusting ±12.5 dB in eleven 2.5 dB steps. Turnover frequencies are switchable (425/250/500 Hz for bass, 2/4/8 kHz for treble), and there is a defeat switch. Low and high filters offer 20/40 Hz and 7/11 kHz cutoffs respectively, each at a steep 18 dB/octave.
There's a built-in microphone amplifier running on the same 162V rail, with its own level control for fading. A mixing record output lets the mic/line mix be captured to tape. The headphone amplifier is a separate circuit with an independent level knob. Two tape monitor loops allow dubbing between decks, the front-panel indicators are LEDs, and every rear-panel connector is gold-plated to prevent poor contact. Rated output is 1V into 600 ohms. Distortion is quoted at 0.01% or less. Phono signal-to-noise is 74 dB at 3mV sensitivity and 70 dB at 1mV, with Tuner/AUX at 90 dB and MIC at 60 dB.
Physically it's a serious lump of 1970s engineering: 440 mm wide, 180 mm high, 397.5 mm deep, 14 kg, drawing 40W from a 100V supply. Beyond that, the documented record is thin. There are no exact production years beyond "around 1973," no other 10000-series models named alongside it, and no period reviews, service notes, or collectibility data in the archive.
Similar items on eBay
No exact Technics SU-10000 listings are live right now — these searches show current Technics and similar vintage audio gear on eBay:
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.