Pioneer SG-90 Graphic Equalizer – 17 Bands, Silver, Japan

Pioneer SG-90 — Seventeen Bands per Channel at 0.001% Distortion

A Japanese-built silver-faced two-thirds-octave equalizer with seventeen bands per channel — thirty-four sliders in total — and a specification sheet that belongs on considerably more expensive equipment.

Seventeen Bands per Channel

Most graphic equalizers give you seven or ten bands per channel, which is enough to shape a sound but not enough to fix a room. The SG-90 gives you seventeen, on two-thirds-octave centres running from 16 Hz to 25,000 Hz. That resolution is the difference between nudging “the bass” and actually addressing the specific 63 Hz peak your room produces because of where the walls are. Anyone who has fought a boomy corner or a hard-surfaced living room will understand immediately why this matters.

Measured Performance

The measured performance is what elevates it. Total harmonic distortion of 0.001% with controls flat, a signal-to-noise ratio of 120 dB, and frequency response from 10 Hz to 100,000 Hz. Those are figures you would expect from serious separates, not from a tone-shaping accessory, and they mean the SG-90 can sit permanently in your signal path without costing you anything when it is not being used. It was built in Japan, in the years when that still described the top of Pioneer’s manufacturing rather than the average of it.

Control Ranges

Two control ranges are provided. The plus or minus 12 dB setting is for normal corrective work; switching to plus or minus 6 dB halves the range across every slider so the same physical movement produces a finer adjustment. It is the difference between a coarse tool and a precise one, and it is exactly what you want once you are past the obvious problems and into the last few decibels.

Beyond Equalization

There is more here than equalization. An auto fader with display creates smooth fade-ins and fade-outs, which is a genuine luxury for anyone still making compilations. The equalizer character selector inverts the entire frequency curve, which allows the SG-90 to perform tape noise reduction by recording with one curve and playing back with its mirror image. Two tape decks can be connected with equalization applied during dubbing, and EQ switches let you equalize what you are listening to while recording the source unequalized. It is a piece built when tape was still how people kept music, and it takes that job seriously.

Connections

Connection is by standard RCA through a tape monitor loop, so it works with essentially any receiver or integrated amplifier that has tape terminals. It is also switchable between 120 and 220 volts.

Condition

Cosmetically graded Good, with honest wear consistent with its age and nothing affecting performance. Thoroughly inspected and tested in-house and working properly.

Seventeen bands per channel with distortion at one thousandth of a percent is a genuinely uncommon combination, and it makes the SG-90 one of the more capable equalizers of its era — a piece that can properly fix a difficult room rather than merely colour it.

Pioneer SG-90 Specifications

• Design: Stereo graphic equalizer, two-thirds octave
• Bands: 17 per channel, 34 total
• Centre frequencies: 16, 25, 40, 63, 100, 160, 250, 400, 630, 1k, 1.6k, 2.5k, 4k, 6.3k, 10k, 16k, 25kHz
• Control range: +/-12dB / +/-6dB, switchable
• Total harmonic distortion: 0.001% (20Hz-20kHz, controls flat)
• Signal to noise ratio: 120dB
• Frequency response: 10Hz-100,000Hz
• Output level: 1V
• Gain: 0dB, controls flat
• Features: Auto fader with display, equalizer character selector (reverse response), two-deck dubbing with EQ, Tape 1 / Tape 2 / Source selection
• Power: 120V / 220V switchable
• Finish: Silver
• Year of introduction: 1983
• Original manufacturer: Pioneer – Made in Japan
• Dimensions: (Width x Height x Depth) 16.54 x 5.16 x 13.82 inches (420 x 131 x 351 mm)
• Weight: 15.9 lbs (7.2 kg)

✅ Good News for International Buyers

This unit is switchable between 120V and 220V, so it can be set to suit most markets worldwide. No step-down transformer is required — only an appropriate plug adapter.

✅ Buy With Confidence — The Radique Promise

Backed by Radique Audio’s Bumper-to-Bumper Warranty and our Perpetual Trade-Back Program. When you’re ready to move on, we’ll take it back. That’s the Radique difference.

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