KENWOOD DA-1100EX
¥ 138,000 (released in 1987)
Commentary
An integrated amplifier equipped with a D/A converter that adopts strut air suspension, clean cyclone power supply and logical flow construction.
In order to accurately synchronize with digital signals with different sampling frequencies and to enable more accurate conversion with the D/A converter, we have adopted a twin quartz PLL system with a two stage PLL. The first stage absorbs external noise and fluctuations due to the input path and reliably captures data. The second stage reads data at more accurate time intervals and sends it to the D/A converter.
In addition, by using extremely stable quartz for the second stage PLL, more accurate D/A conversion is possible.
The D/A converter is equipped with a real step full-bit D/A converter.
In this D/A converter, the distortion of the MSB and 2 sb is compensated by an original method, and the high-speed C-MOS gate array is made into an original IC, and as a one chip IC configuration with no delay amount, the distortion is sufficiently removed from small amplitude signals to large amplitude signals.
We have newly developed and adopted a strut air suspension to suppress noise and distortion caused by external vibration.
This suspension is a unique independent suspension vibration absorption system. Vibration from the floor is first absorbed by the special elastic rubber at the grounding section. Furthermore, large amplitude vibration that could not be absorbed by the special elastic rubber is smoothly absorbed by the following coil spring and air damper.
In addition, these main parts are made of aluminum die-cast movable parts with high rigidity, and vibration from the floor is eliminated as much as possible.
In addition, the casing is made of a high-strength vibration-proof casing bonded with iron plates. By increasing the weight and adopting new structures such as logical flow construction, sound quality degradation is prevented.
In order to reduce the effect of sound quality degradation caused by home power supply, we have adopted an independently developed clean cyclone power supply.
By adding a special clean cyclone device to the transformer winding, this technology does not change digital noise in the high-frequency range into secondary voltage. This improves the bare characteristics of the power supply itself and improves the quality.
In addition, by fusing with the DLD circuit that eliminates the interference between the voltage amplification stage and the power stage that occurs through the power supply, and with the NEW VIG circuit that improves the SVR of the amplifier, the influence of the AC power supply and power supply circuit on the amplifier circuit is reduced.
The internal structure employs a 5-box logical flow construction. The shield plate completely separates the small signal and large signal, digital signal and analog signal, and each signal processing part and power supply to suppress mutual interference.
In addition, by placing the transformer in the center, the merits of the strut air suspension can be maximized, and vibration damping effect is also improved.
The heat sink uses a chimney type heat sink with excellent heat radiation effect and vibration isolation.
Equipped with a Σ drive circuit that realizes high damping factor.
Dual Rec Selector with Source Selector function and CD Direct Switch are installed.
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Model Rating
| Type | Integrated amplifier with built-in D/A converter |
| Amplifier Unit | |
| Rated Output (20 Hz to 20 kHz, Both Channel Operation) | 145W + 145W (6 Ω, THD 0.006%) 125W + 125W (8 Ω, THD 0.004%) |
| Dynamic Power | 325W (2 Ω) 270W (4 Ω) 150W (8 Ω) |
| Total Harmonic Distortion Factor (CD) | 0.0006% (at rated output, 1 kHz, 8 Ω) 0.004% (Rated Output, 20 Hz to 20 kHz, 8 Ω) 0.003% (20 Hz to 20 kHz at 1/2 Rated Output) |
| Intermodulation distortion factor (60 hz : 7 khz = 4 : 1) | 0.004% (8 Ω at rated output) |
| Frequency Response (Line → Speaker) | 5 Hz ~ 80 kHz + 0 -3dB |
| Damping factor | 1000(50Hz) |
| Input Sensitivity / Impedance | Phono MM : 2.5mV/47k Ω Phono MC : 0.2mV/100 Ω DAT, CD, Tuner, Aux, Tape : 150mV/47k Ω |
| SN ratio (input short / EIAJ) | Phono MM:87dB/78dB Phono MC:70dB/74dB DAT, CD, Tuner, Aux, Tape : 108dB/82dB |
| Tone control | Bass : ± 10 dB (200Hz/400Hz) Treble : ± 10 dB (3kHz/5kHz) |
| Loudness control (Vol-30dB) | 9dB(100Hz) |
| Subsonic filter | 18 Hz, -6dB/oct. |
| Output bandwidth (0.04% distortion rate, 8 Ω) | 5 Hz to 50 kHz |
| Phono maximum allowable input (Phono → Tape Rec, 1 khz, 0.004%) |
Phono MM:200mV Phono MC:15mV |
| Output Level / Impedance | Tape rec : 150mV/330 Ω |
| D/A Converter Unit | |
| Corresponding sampling frequency | 32 kHz, 44.1 kHz, 48 kHz (automatic switching) |
| Signal-to-noise ratio (EIAJ) | 108dB |
| Distortion Factor (EIAJ) | 0.0025% |
| Channel Separation (EIAJ) | 103dB |
| Digital input | Optical received power : -15dBm to -25dBm Coaxial : 0.5Vp-p/75 Ω DAT Monitor : 0.5Vp-p/75 Ω |
| Digital output | Coaxial : 0.5Vp-p/75 Ω |
| <General> | |
| Power outlet | Power switch interlock : 1 system, 100W Power switch not linked : 2 systems, 400W |
| Pwer | 100 VAC, 50Hz/60Hz |
| Rated power consumption (Electrical Appliance and Material Control Law) | 320W |
| Maximum external dimensions | Width 440x Height 171x Depth 441 mm |
| Weight | 19.5kg |