KRELL KMA-100
¥ 1,350,000 (1 set of 2, released in 1983)
Commentary
This monaural power amplifier was developed based on the KSA-100 to further explore its potential.
The basic circuit system is inherited almost as it is from the KSA-100, a stereo unit.
Pure A-Class operation is adopted, which in principle does not cause switching distortion or crossover distortion. Pure complimentary service circuit with perfect symmetrical operation is adopted in the circuit structure. For example, not only the simple amount of harmonic distortion components, but also the appearance of the distortion mode, which has a large effect on audibility, is taken into consideration when selecting the circuit. In addition, NFB is limited to 15 dB or less, and dynamic characteristics are emphasized so that dynamic distortion does not occur.
In the power block, heat radiation fins and quiet cooling fans are combined, and heat generation in pure A class operation is coped with and thermal distortion is suppressed by strict temperature control of 75 to 80 degrees Celsius.
The power supply unit has a larger capacity than that of the KSA-100 in the space obtained by monaural conversion.
It uses two separate power supply systems for the pre-driver stage and output stage. The power supply for the output stage is equipped with a 160,000 μ F capacitor, which is twice the size of the stereo KSA-100, and a 1.1 kW-class large toroidal transformer with excellent regulation.
Equipped with a terminal for BTL connection, BTL drive using two KMA-100 units for one channel is possible.
The KMA-100 can produce almost four times the output power, as calculated, while most amplifiers can produce only about three times the output power when connected to a BTL.
Model Rating
| Type | Monaural power amplifier |
| Rated Output (20 Hz to 20 kHz, Continuous) | 100W (8 Ω) |
| Input Sensitivity / Impedance | 1.2V/22k Ω |
| Total harmonic distortion factor | 0.05% or Less (20 Hz to 20 kHz, 1W to Rated Output) |
| Frequency characteristic | 0.5 Hz to 100 kHz -3dB 20 Hz ~ 20 kHz -0.5 dB (1W ~ Rated Output) |
| Signal-to-noise ratio | 110dB(IHF-A) |
| Rated load impedance | 2 Ω or more |
| Damping factor | 150(1kHz) |
| Slew rate | 250 V / μ sec |
| Pwer | 100 VAC, 50Hz/60Hz |
| Power consumption | 300W (per vehicle at idle) |
| External dimensions | Width 483x Height 226x Depth 480 mm |
| Weight | Approximately 25 kg |
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