Technics SU-TX50 (1996)
A 5-channel AV amplifier built to satisfy Dolby Pro Logic's ideal surround condition with a 120Wx3 + 100Wx2 output.
Overview
At 12.0 kg, the Technics SU-TX50 sits in a system as a substantial piece of equipment, capable of handling 480W of power consumption while maintaining a rated distortion factor of 0.05% across stereo channels. This unit is recognized as part of Technics' prestigious Reference Series, originally priced at ¥125,000. It is designed as an AV amplifier and Home THX control amplifier, utilizing a unique enhanced class H circuit to deliver high output within conventional amplifier sizes. The power amplifier section uses three hybrid ICs to achieve a large output of 120Wx3 + 100Wx2, solving the distortion issues often found in conventional Class H amplifiers. This configuration allows for a home THX audio system realization developed by Lucasfilm, alongside Dolby Pro Logic decoding.
It features a 5-channel configuration that satisfies Dolby Pro Logic's ideal surround condition of "using the same speakers for L/R / Center and driving with the same power." The preamplifier section frequency characteristic covers 20 Hz to 20 kHz ± 1.0 dB across tuner, CD, tape, and VCR inputs. The signal-to-noise ratio reaches 70 dB (EIAJ) for these channels. The power amplifier unit rated output for Dolby Pro Logic Home THX Cinema time provides 120W + 120W for Front channels, 120W for Center, and 100W + 100W for Surround channels at 6 ohms, 1 kHz, 0.8%. This output level is designed to drive speakers with consistent power requirements across the surround field.
Additional features include a Sound Field Control (SFC) that allows selection from seven sound fields, such as halls and live houses. You can surround sound playback from stereo sources such as non-Dolby encoded CDs and cassette tapes using DSP signal processing. The 3-mode SSI (Sound Stage Imaging) feature allows you to create a more natural and expanded sound field when playing back a normal stereo source. It is equipped with a decoder for a home THX audio system that realizes the THX sound system at home. The unit also features digital delay circuitry where the delay time can be varied from 15 to 30ms in 5ms steps. Discrete 6-channel inputs are used to support multi-channel outputs such as a digital surround processor that decodes Dolby Digital (AC-3) or a DVD player with 5.1 channel decoded outputs.
Specifications
| Manufacturer | Panasonic/Technics |
| Exact product name | Technics SU-TX50 |
| Production years | 1996 |
| Original price | ¥125,000 |
| Power Amplifier Unit Rated output (Dolby Prologic Home THX Cinema time) | Front : 120W + 120W (6 ohm, 1 khz, 0.8%); Center : 120W (6 Ω, 1 kHz, 0.8%); Surround : 100W + 100W (6 ohm, 1 khz, 0.8%) |
| Rated Output (Stereo) | 125W + 125W (20 Hz to 20 kHz, 6 Ω, 0.05%) |
| Rated distortion factor | 0.05% (20 Hz to 20 kHz, Rated Output, 6 Ω) |
| Total harmonic distortion factor | 0.03% (1 kHz, rated output -3dB, 6 Ω, sum up to 10th harmonic) |
| Damping factor | 25 (6 Ω) |
| Load impedance | A or B : 4 Ω ~ 16 Ω; A + B : 8 Ω ~ 16 Ω |
| Preamplifier Section Frequency characteristic | Tuner, CD, Tape, VCR1/2/3, VDP, VDP6ch, TV, TV4ch : 20 Hz to 20 kHz ± 1.0 dB |
| Input Sensitivity / Impedance | Tuner, CD, Tape, VCR1/2/3, VDP, VDP6ch, TV, TV4ch : 300mV/34k Ω |
| Signal-to-noise ratio | Tuner, CD, Tape, VCR1/2/3, VDP, VDP6ch, TV, TV4ch : 70 dB (EIAJ) |
| Tone control characteristics | Bass : ± 10 dB (50 Hz); Treble : ± 10 dB (20 kHz) |
| Rated output voltage / impedance | Tape, VCR1 (recording output) : 300mV/2k Ω; Decoder Output : 1V/470 Ω |
| Image Section Output voltage (at 1 V input) | 1 ± 0.1Vp-p |
| Image Section Maximum Input Voltage | 1.5Vp-p |
| Image Section Input-output impedance | 75 Ω (unbalanced) |
| Power | 100 VAC, 50Hz/60Hz |
| Power consumption | 480W |
| External dimensions | Width 430x Height 170x Depth 375 mm |
| Weight | 12.0 kg |
| Watts rms | 120 |
| Power bandwidth | 20-20 kHz |
| Smtpe im | 0.05% |
| Phono Input | MM and MC (switchable) |
Key Features
Enhanced Class H Circuit
The power amplifier section uses a unique enhanced class H circuit to deliver high efficiency and low distortion rate. By using three hybrid ICs, a large output of 120Wx3 + 100Wx2 is achieved with a conventional amplifier size. The problem of distortion, which was a drawback of the conventional Class H amplifier, has been solved. This circuitry enables the unit to meet the power demands of a Home THX system while maintaining a damping factor of 25 at 6 Ω.
Dolby Pro Logic and THX Decoding
Equipped with Dolby Pro Logic, the SU-TX50 uses a 5-channel configuration that satisfies Dolby Pro Logic's ideal surround condition of "using the same speakers for L/R / Center and driving with the same power." It has three built-in surround modes: normal, wide and phantom. It is equipped with a decoder for a home THX audio system that realizes the THX sound system at home developed by Lucasfilm. The unit supports discrete 6-channel inputs to support multi-channel outputs such as a digital surround processor that decodes Dolby Digital (AC-3) or a DVD player with 5.1 channel decoded outputs.
Sound Field Control and Imaging
It is equipped with a Sound Field Control (SFC) that allows you to select from seven sound fields, such as halls and live houses. The 3-mode SSI (Sound Stage Imaging) feature allows you to create a more natural and expanded sound field when playing back a normal stereo source. You can surround sound playback from stereo sources such as non-Dolby encoded CDs and cassette tapes using DSP signal processing. The
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