SONY STR-7025
¥ 57,800 (around 1975)
Commentary
AM/FM stereo receiver with improved operability.
A newly developed junction FET has been adopted for the FM front end to improve the receiving capability.
In addition, a solid-state filter is used in the IF section to sharpen the separation of adjacent channels.
Frequency number line type varicon is used, and more accurate tuning is possible by dialing at equal intervals.
Solid state filter is used in the AM tuner section.
The power amplifier section uses a two power direct coupling system using a hybrid power IC.
The tone control circuit uses NF type.
It has a built-in microphone amplifier for mixing.
Equipped with a loudness switch and a filter switch.
.JPG)
Model Rating
| Type | All-silicon transistor FM/AM stereo receiver |
| Circuit system | Power amplifier 2 power supply Direct coupling pure complimentary service SEPP circuit |
| FM Tuner Section | |
| Receiving frequency | 76 MHz to 90 MHz |
| Sensitivity | 2.2 μ V (IHF) 1.7 μ V (S/N 30 db) |
| Signal-to-noise ratio | 68dB |
| Capture ratio | 1.5dB |
| Selectivity (IHF) | 60dB |
| Image interference ratio | 55dB |
| Intermediate frequency interference ratio | 90dB |
| Spurious interference ratio | 78dB |
| AM suppression ratio | 55dB |
| Frequency characteristic | 30 Hz ~ 15 kHz + 0 -1dB |
| Distortion Factor (400 Hz, 100% modulation) | mono:0.3% stereo:0.8% |
| Separation | 35 dB or More (400 Hz) |
| Antenna terminal | 300 Ω Balanced Type 75 Ω Unbalanced Type |
| <AM Tuner Section> | |
| Receiving frequency | 530 kHz to 1605 kHz |
| Intermediate frequency | 455kHz |
| Sensitivity | 48dB/m (when bar antenna is used) 30 μ V (when external antenna is used) |
| S/N | 50dB |
| Image interference ratio | 56dB(1000kHz) |
| IF interference ratio | 40dB(1000kHz) |
| Distortion factor | 0.8% |
| Antenna | Ferrite bar antenna With External Terminal |
| Power Amplifier Unit | |
| Effective output (both channel drive) | 18W + 18W (8 ohm, 40 hz to 20 khz) 24W + 24W (4 ohm, 1 khz) 20W + 20W (8 ω, 1 kHz) |
| Dynamic Power (IHF) | 70W (4 Ω) 55W (8 Ω) |
| Harmonic distortion factor | 0.8% or Less (Rated Output) 0.1% or Less (at 1W Output) |
| Cross modulation distortion factor (60Hz:7kHz=4:1) |
0.8% or Less (Rated Output) 0.1% or Less (at 1W Output) |
| Damping factor | 25 or More (1 kHz, 8 Ω) |
| Preamplifier Section | |
| Input Sensitivity / Impedance | Phono : 2.5mV/47k Ω Aux, Tape1, 2, Rec/PB (input section) : 250mV/100k Ω Mic : 2mV/47k Ω |
| Signal-to-noise ratio | Phono : 60 dB or more (input 2.5 mV, B network) Tape1, 2 rec / PB (input section) : 80 dB or more (input 250 mV, A network) Aux : 70 dB (input 250 mV, A network) Mic : 60 dB (input 2 mV, B network) |
| Output Level / Impedance | Rec out : 250mV/10k Ω Rec/PB (Output Part) : 30mV/82k Ω |
| Frequency characteristic | Phono : RIAA curve ± 2 dB Aux, Tape, Rec/PB (input section) : 30 Hz ~ 40 kHz + 0 -3dB Mic : 30 Hz ~ 10 kHz + 0 -3dB |
| Tone control | Bass : + / - 10 dB (100 Hz) High tone : ± 10 dB (10 kHz) |
| Filter | High Filter : 5 kHz, 6dB/oct. |
| <General> | |
| Semiconductor used | Transistor : 34 (including FET) IC : 2 Diode : 21 |
| Pwer | 100 VAC, 50Hz/60Hz |
| Power outlet | Power switch not linked : 150Wx2 systems |
| Power consumption | 80W |
| External dimensions | Width 427x Height 149x Depth 340 mm |
| Weight | 8.5kg |