DENON TUA-600
¥ 88,000 (around 1980)
Commentary
A tuner amplifier that integrates a synthesizer tuner with 16-station preset and a pre-main amplifier with MC input.
The tuner section uses a synthesizer system.
In this system, the reference frequency obtained from the crystal oscillator and the frequency obtained by dividing the local oscillation frequency are compared in phase, and the varicap servocontrol is performed. Therefore, there is no drift of the local frequency due to temperature change, etc., and good and stable reception is possible.
A 4-stage varicap and MOS FET are used in the front end to realize high sensitivity reception and improve the interference rejection capability. The intermediate frequency amplifier (IF) section employs a two stage linear phase ceramic filter configuration to reduce distortion. In addition, a new Quadrature detection circuit is used in the detection circuit.
The AM tuner is an IF stage that combines a coil with two stages of newly developed 3-terminal type high-selectivity ceramic filters to suppress 9 kHz beat interference.
In addition, we have adopted a low-impedance loop type antenna that is resistant to electric-field noise. This antenna is designed to be attached to and detached from the back panel so that it can be installed in a place with good reception.
Each 8 FM/AM stations can be selected for memory music. After selecting the desired station, press the memory button and the preset 1 to 8 buttons to store the desired station.
Equipped with an automatic tuning function, it automatically searches for the radio wave of the broadcasting station from the lower frequency to the higher frequency by pressing the auto button, stops at the tuning point and searches for the next tuning point by pressing the switch again.
Manual tuning is possible by operating the up and down tuning buttons. The reception frequency is displayed on a digital counter, enabling you to catch weak radio waves that cannot be caught by automatic tuning. In addition, the frequency counting speed is designed to increase gradually by holding down the up / down tuning button.
Each of the up / down tuning buttons changes by FM100kHz and AM9kHz in one push operation.
It is equipped with a memory circuit for storing the state before turning off the power. In normal use, the memory lasts for about 3 months after turning off the power.
Non-switching A system is adopted for the power amplifier section.
In this system, a newly developed bias circuit is used for the bias current supply system of the power transistor, and the power transistor is controlled so that a stable bias current flows at all times to prevent cutoff of the power transistor, thereby eliminating switching distortion and reducing crossover distortion.
The basic configuration of the power amplifier consists of a two stage DC-differential driver stage + a pure complimentary service push-pull stage and a newly developed real-time current limiter in the final stage.
Regulation is improved by using a large transformer in the power supply section, and leakage flux is reduced by applying multiple shields to the core to cope with high-density construction inside the chassis.
The tuner section and the preamplifier section (tone amplifier section) are supplied with secondary windings that are independent from the power circuit to reduce mutual interference.
The tone control circuit uses a one time constant tone circuit.
The basic configuration of this circuit is an NF-type tone circuit with a proven track record, but positive improvements have been added to it. This circuit greatly improves the frequency characteristics in the tone flat state, and the effect on sound quality is minimized by a unique circuit that reduces the amount of capacitors in the circuit.
The equalizer amplifier section is compatible with both MC and MM cartridges.
The circuit configuration is a direct-coupled system with a low-noise dual-FET in the first stage, eliminating the coupling and condenser. This reduces the deterioration of the sound quality at the input stage, and high-speed and high-gain amplification with an IC operational amplifier.
In addition, the RIAA deviation is improved by adopting a precise RIAA element.
The MC/MM selector switch is designed to remotely control the switch on the board by means of a flexible wired switch, thereby suppressing degradation of characteristics caused by wire routing.
DENON's unique switch system is used for program selection.
In this system, the switch on the panel drives the C-MOS IC on the circuit board and switches functions to prevent the deterioration of sound quality.
Equipped with two speaker output jacks.
Equipped with two tape deck input / output terminals.
Equipped with a subsonic filter and loudness control.
Equipped with double protection circuit to protect speakers and power transistors.
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Model Rating
| Type | FM/AM tuner amplifier |
| FM Tuner Section | |
| Receiving frequency | 76 MHz to 90 MHz |
| Antenna terminal | 75 Ω, 300 Ω (Terminal Type) |
| Practical sensitivity | 1.8 μ V/10.2 dBf |
| S/N50dB sensitivity | Stereo : 31.6 μ V/35.2 dBf Mono : 3 μ v/14.2 dBf Where μ V is 300 Ω and 0 dBf is 10.-15W (new IHF standard) |
| Image interference ratio | 75dB |
| IF interference ratio | 98dB(76MHz) |
| Spurious response | 80dB(83MHz) |
| AM suppression ratio | 50 dB (IHF standard) |
| Effective selectivity | 60 dB (± 400 kHz) |
| Capture ratio | 1.2dB |
| Frequency characteristic | 20 Hz ~ 15 kHz + 0.2 -1dB |
| Signal-to-noise ratio | stereo:68dB mono:74dB |
| Total harmonic distortion factor | stereo:0.2% mono:0.1% |
| <AM Tuner Section> | |
| Receiving frequency | 531 kHz to 1,602 kHz |
| Antenna | Terminal type, loop type ferrite antenna included |
| Practical sensitivity | 300 μ V/m (S/N 20 dB) |
| Selectivity | 35 dB (± 9 kHz) |
| Power Amplifier Unit (Aux in-Speaker out) | |
| Rated output (both channel drive, sine wave continuous output 20 Hz to 20 kHz) |
65W + 65W (4 Ω) 60W + 60W (8 Ω) |
| Input Sensitivity / Impedance | 150mV/30k Ω |
| Total harmonic distortion factor | 0.03% or Less (at 1 kHz, Rated Output -3dB) |
| Intermodulation distortion factor (60 hz : 7 khz = 4 : 1) | 0.03% or Less (at Rated Output Equivalent Amplitude Output) |
| Output Bandwidth (IHF, both channel drives) | 10 Hz ~ 30 kHz (THD 0.5%) |
| Frequency characteristic | 10 Hz ~ 30 kHz ± 0.5 dB (at 1W Output) |
| Output impedance | 0.1 Ω or less |
| Output terminal | Speaker : AORb, A + B (4 Ω ~ 16 Ω) Headphone : Stereo headphone (8 Ω ~ 200 Ω) |
| Preamplifier Section (Phono In-Rec Out Excluding Input Sensitivity / Impedance) | |
| Input Sensitivity / Impedance | Phono MM : 2.5mV/47k Ω Phono MC : 0.3mV/100 Ω Aux, etc : 150mV/30k Ω |
| Maximum Output / Rated Output | 10V/150mV |
| Signal-to-noise ratio | Phono MM:86dB Phono MC:72dB |
| RIAA deviation | MM/MC : 20 Hz to 20 kHz ± 0.3 dB |
| Total harmonic distortion factor | 0.002% or Less (at 6 V output) |
| <Main Attached Functions> | |
| Tone control | Bass : ± 10 dB (100 Hz) Treble : ± 10 dB (10 kHz) |
| Subsonic filter | 15 Hz, 6dB/oct. |
| Loudness control | Low : + 8 dB (100 Hz) High frequency : + 4 dB (10 kHz) |
| <General> | |
| Pwer | 100 VAC, 50Hz/60Hz |
| Power consumption (Electrical Appliance and Material Control Law) | 145W |
| External dimensions (including knob, rubber leg, terminal) | Width 434x Height 112x Depth 408 mm |
| Weight | 11kg |