Sony TA-1120A

At 11 kilograms and loaded with silicon transistors, this 1967 flagship was Sony's bid for the high-end audio market.

Overview

The Sony TA-1120A isn't a subtle machine. Lift it and you feel the 11 kg. Released in 1967, it was Sony's first major push into upper-end home audio, and a statement that Japanese engineering could rival the best from the West. It's a premain design, meaning the preamp and power amp sections are integrated but independent enough to be used separately if needed. The entire signal path uses silicon transistors, chosen for their stability under temperature swings and strong high-frequency behavior. The power stage is a quasi-complementary SEPPP OTL configuration, fully discrete, and the parts list is headed by 46 transistors and 23 diodes, many of them now long out of production. It was never meant to be discreet.

Specifications

Manufacturer	Sony
Product Type	All-silicon transistor stereo premain amplifier
Original Price	¥ 96,000
Power Amplifier Unit Output	Non-clip music Power: 160W (8 Ω, both channel operation); Music Power (IHF): 60W + 60W (8 Ω, both channel operation); Rated output: 60W + 60W ± 0.5 db (4 Ω); Rated output: 50W + 50W ± 0.5 db (8 Ω); Rated output: 35W + 35W ± 0.5 db (16 Ω)
Harmonic Distortion Factor (Power Amp)	1kHz: 0.05% or Less (at Rated Output); 1kHz: 0.01% or Less (at 10W Output); 20 Hz to 15 kHz: 0.1% or Less (at Rated Output); 20 Hz to 15 kHz: 0.06% or Less (at 25W output); 20 Hz to 15 kHz: 0.03% or less (at 500 mW output)
Cross Modulation Distortion Factor (Power Amp, SMPTE standard 60Hz:7kHz=4:1)	0.2% or Less (Rated Output); 0.05% or Less (at 25W Output); 0.02% or Less (at 10W Output)
Frequency Characteristic (Power Amp)	7 Hz ~ 180 kHz + 0 -1dB (at Rated Output)
S/N Ratio (Power Amp, IHF standard Closed circuit)	110 dB or more
Input Impedance (Power Amp)	100k Ω or more
Damping Factor (1 kHz)	180 or More (8 Ω); 360 or More (16 Ω)
Sensitivity (Power Amp)	1 V (at 50W output)
Residual Noise (Power Amp)	0.1 μ W or Less (8 Ω)
Preamplifier Section Output	Pre-out: 2V/10k Ω; Headphone: 6V/10k Ω; Rec out: 150mV
Harmonic Distortion Factor (Preamp, at rated output)	Tuner, Aux, Tape: 0.03% or less; Mic: ≤ 0.05%; Tape head: 0.05% or less; Phono1/2: 0.05% or less
Cross Modulation Distortion Factor (Preamp, 60Hz:7kHz=4:1)	Tuner, Aux, Tape: 0.1% or less; Mic: ≤ 0.1%; Tape head: 0.1% or less; Phono1/2: 0.1% or less
Frequency Characteristic (Preamp)	Tuner, Aux, Tape: 10 Hz to 100 kHz + 0 -2dB; Phono1/2: deviation from RIAA curve within 0.5 dB; Tape head: Deviation from NAB curve within 0.5 dB; Mic: 10 Hz to 30 kHz + 0 -2dB
Sensitivity (Preamp)	Tuner, Aux: 150mV/100k Ω; Tape: 150mV/100k Ω; Phono1/2: 1.2mV/47k Ω; Tape Head: 1.2mV/500k Ω; Mic: 1.2mV/500k Ω
Maximum Undistorted Allowable Input (1 kHz, Preamp)	Phono1/2: 100mV; Tape head: 100mV; Mic: 100mV
Signal-to-Noise Ratio (Preamp)	Aux, Tuner: 90 dB or more; Phono1/2: 70 dB or more; Tape head: 70 dB or more; Mic: 65 dB or more
Tone Control	Bass: 100 Hz ± 10 dB; Treble: 10 kHz ± 10 dB (2 dB Step 11-Stage Switching)
Filter	Low Filter: 50 Hz or less, 12dB/oct.; High Filter: 9 kHz or higher, 12dB/oct.
Semiconductor Used	Transistor (46 pcs) 2SC401: 25 2SC293: 8 2SA527: 2 2SC318: 3 2SD45: 8; Diode (23 pcs) DS2M: 4 pcs 1T22: 2 SV-03: 2 SV-05: 4 SV-31: 10 1S332: 1
Power	100 VAC (Switchable to 117 V, 220 V, 240 V) ± 10%, 50Hz/60Hz
Power Outlet	Power switch interlock: 2 systems; Power switch not linked: 1 system
Power Consumption	No signal: about 40W; Rated output: approximately 260W
External Dimensions	Width 400x Height 145x Depth 310 mm
Weight	Approximately 11 kg
Attachment	Short plug Pin plug Connection code Silicon cloth 5A fuse
Sold Separately	Eurasian Cheek Finish Wood Case TAC-1 (¥ 4,600); Mounting Bracket MB-5 (¥ 2,800)

Key Features

Quasi-Complementary SEPPP OTL Power Circuit

The TA-1120A's power amplifier uses a quasi-complementary SEPPP (Series Push-Pull, Paralleled) OTL (Output TransformerLess) design. In 1967 that was a sophisticated choice. It avoids the coloration and bandwidth limits of output transformers and delivers high current into low impedances. Silicon transistors throughout gave better thermal stability than germanium, which matters in a high-power, tightly packed chassis. Measured damping factor is 180 or more into 8Ω, which was exceptional for the era, and it gives tight control over speaker cones.

Lever-Operated Quick-Access Input Switch

The front-panel lever switch toggles instantly between two preset inputs, typically Tuner and Phono1. If other inputs are pre-selected with the main rotary switch, the lever effectively gives you a three-input quick-select system. It reflected Sony's focus on usability, letting users switch between their most-used sources without fumbling with a knob.

2 dB Step Tone Control with Flat Cancel

The tone controls work in 2 dB increments across 11 steps. A dedicated tone cancel switch returns the signal to flat regardless of the knob positions. Users could dial in a favorite EQ curve and bypass it instantly, with no need to line the knobs up on a center detent.

Independent Preamp and Main Amplifier Operation

Though housed in a single chassis, the preamp and power amp sections are functionally separable. The pre-out and main-in jacks let the TA-1120A act as a standalone preamplifier driving an external power amp, or as a power amp fed by another preamp. This was rare in integrated units of the time, and it points to Sony's intent to position this as a modular component within a larger system.

Kooky Red Capacitors

Inside, the amplifier keeps its original red-bodied capacitors, which have become a visual hallmark. Their electrical performance degrades with age, and their failure is a common restoration hurdle. Their distinctive look is often preserved during servicing when possible.

Historical Context

The TA-1120A arrived in 1967 as the direct successor to the TA-1120, with improved circuitry and tighter specifications. It was Sony's serious entry into the high-fidelity market, which was then dominated by Western brands. Its engineering priorities were modularity, precision and measurable performance. The early 1970s TA-1130 moved toward a more refined, minimalist front panel.

Collectibility & Value

Specific market values aren't documented in the primary source, but owner reports indicate increasing demand on secondary markets, with some owners expressing surprise at rising eBay prices. Collectibility comes from its status as an early Sony flagship and its advanced-for-the-time engineering. It does have issues. Common failures include noise, DC offset voltage at the outputs, and capacitor degradation, particularly in units manufactured before 1968. The main RC snubber capacitor has been known to fail catastrophically. Service and user manuals are available through niche vendors.

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