m Pure Class A operation delivers quality power: 60 watts × 2 into 8 ohms m Power MOS-FET output stage features 10-parallel push-pull configuration m Input circuitry with MCS topology m Current feedback design combines superb sound with total operation stability m Bridged mode allows use as a monaural amplifier m Massive Super Ring toroidal transformer rated for 1 kVA
m Dual-function power meters show digital readout or bar graph display
Aiming for the ne plus ultra Experience the peerless sound of pure class A
and MOS-FETs. Input stage with MCS topology assures impeccable performance in all aspects with minimum noise and distortion. 10-parallel pushpull power MOS-FETs operating in pure class A, and power supply with massive 1 kVA toroidal transformer deliver linear power into ultra-low impedances down to 1 ohm. 4-step gain selector further reduces residual noise.
Note 1
Low amplifier output impedance
The load of a power amplifier, namely the loudspeaker generates a counterelectromotive force that can flow back into the amplifier via the NF loop. This phenomenon is influenced by fluctuations in speaker impedance, and interferes with the drive performance of the amplifier. The output impedance of a power amplifier should therefore be made as low as possible by using output devices with high current capability. This absorbs the counterelectromotive force generated by the voice coil and prevents the occurrence of intermodulation distortion.
Note 2
The constant drive voltage principle
Even in the presence of a load with wildly fluctuating impedance,
the ideal power amplifier should deliver a constant voltage signal to the load. Figure 2 shows the results of actual output voltage/
output current measurements at different load impedances for the
A-60. It can be clearly seen that output voltage is almost constant at various loads, which means that current increases in a linear fashion. Actual measurements of clipping power have yielded the following figures, which impressively demonstrate the more than ample performance of the A-60: 1 ohm: 513 watts, 2 ohms:
343 watts, 4 ohms: 202 watts, 8 ohms: 110 watts.
Power MOS-FET output stage with 10-parallel pushpull power units delivers 480 watts into 1 ohm, 240
watts into 2 ohms, 120 watts into 4 ohms, or 60
watts into 8 ohms with outstanding linearity
* 1-ohm loads to be driven with music signals only
The output stage (Figure 1) uses power MOS-FETs.
10 pairs of these devices are arranged in a parallel
funktionshandbuch.jpg)
