When you hear the name ‘Sony’, the first thing that comes to mind are probably boring blackface units from the 80’s and 90’s rather than silver beauties from the “golden” years of audio. But this Japanese manufacturer was quite active in the 1970s and made quite a few of very decent amps and receivers.
The integrated amplifier Sony TA-1055 was manufactured in 1973-74. Sony also offered 2 updated versions: the TA-1055A (front AUX input replaced with mic mixing potentiometer) and TA-1070 (front AUX input replaced with mic mixing potentiometer and 6.3 mm jack microphone connectors instead of 3.5 mm jacks). The models Sony TA-1066 and its updated version TA-1090 were also very similar.
Typically for this period, the amplifier has very good looks, with the classic silver face and the top cover and sides in wood. The functions are clearly arranged: on the left you will find the power switch and headphone jack (bottom), speaker switches and filters.
Volume and tone slider potentiometers are center-left, and to the right there are mono/stereo switch and sound source switches. Below the right-side group of switches there is an additional AUX input (6.3 mm jack, just like the headphone jack) and microphone jacks (3.5 mm type).
All switches (except the power switch) are in the same style buttons arranged in one line; the power switch at the bottom is in one line with the sockets. In short, the front panel is aesthetically designed and the functions clearly arranged. We find similar order in the back; easy access to speaker fuses and voltage selector switch is a huge advantage.
Order reigns inside, too: the layout is clear with particular sections clearly distinguished, the phono stage section and the power supply are on the opposite ends and the phono stage is additionally shielded with a metal cover. The transformer is also shielded, and each output transistor has its own, decent size heat sink. The only IC is in the phono stage section. For comparison, the TA-1066 has a smaller heat sink, but the phono stage section is fully discrete.
From the functional point of view, the amplifier is quite friendly, but it does have a few flaws. The biggest of them are the volume potentiometers: not only are they sliders (like tone control pots), they are also separate for the left and right channels. While this solution looks good, it’s quite user-unfriendly: each time you change the volume, you must first adjust one channel, and then use the second slider to match the volume of the other channel. This is quite annoying; the sibling model TA-1066 has also has 2 slider pots, but it is a single volume potentiometer for both channels and a separate balance pot. The second problem are the speaker terminals. These are ordinary flat head screws. They must be tightened with a screwdriver and it is a real challenge to secure even a thin cable, and a thicker one is out of the question. Turntable users might be put off by the lack of low filter. And finally bad news for fans of lights: the amplifier has no “beautifiers” like colored lamps for various functions, meters, etc. Only the green lamp next to the power switch indicates that the amplifier is on.
Fortunately, the amplifier’s sound more than makes up for these inconveniences. It created a good sound stage and the sound it delivers is detailed, dynamic, quite neutral on the warm side, full with very good bass, smooth midrange, clear and pleasant highs. Due to the fairly neutral sound, it is not picky when it comes to music genres. While it is not a power demon (20 watts continuous power per channel) and won’t handle very loud listening in a large room, it works great in smaller and medium-sized room, even with more demanding, low impedance loudspeakers. For me personally, this is one of the nicest playing amplifiers of this class from the 1970s. The built-in phono stage is quite average, but should do the trick for an undemanding listener.
Sony TA-1055 is not a very powerful, but very good sounding, aesthetic and quite functional amplifier. Definitely recommended for small and medium rooms. It looks great in a set with its companion tuner (ST-5055). We assume that its two updated versions (TA-1055A and TA-1070) are just as good; in the case of “sibling” models TA-1066 and TA-1090 we would suggest choosing less demanding speakers due to less efficient cooling.
Model: Sony TA-1055
Years of manufacture: 1973-74
Country of manufacture: Japan
Continuous power – 2x20W at 8 ohms, 2x27W at 4 ohms
Music power – 2x35W at 8 ohms, 2x45W at 4 ohms
THD – less than 0.5%
IM – less than 0.5%
Power bandwidth – 10 Hz – 40 kHz
Frequency response – 10 Hz – 60 kHz +/- 3 dB (line), RIAA curve +/- 1 dB (MM)
Damping factor – 22
Input sensitivity: 2mV (mic), 2mV (MM), 250mV (line)
S/N: 65dB (mic), 70dB (MM), 90dB (line)
Output: 250mV (line), 30mV (DIN)
Inputs/outputs: Tape 1 (I/O), Tape 2 (I/O), Aux, Tuner, Phono (MM), Mic L+R, 2 pairs of speakers, headphone jack
Power consumption (max): 165W
Dimensions: 410 x 120 x 280 mm
Weight: 6.2 kg