Solid state stereo power amplifier
The D200, D300 and D400MKII use similar means to achieve a common goal of musicality at different power levels. In
the case of the D200 and D300, the general circuit topology is identical with quantitative differences applying in
power-supply energy storage and number of output devices (see specifications for details). The D400MKII, while largely
similar in design, also has some features which are uniquely its own.
The D200, D300 and D400MKII all use direct-coupled, high- current Multiple-Emitter Transistors (or METs) in their output stages (as well as for input-stage drivers). These devices have the rugged, high- heat, high-current capability of single emitter bipolar transistors (which can have a rougher, harder sonic character), but they also have a natural sweetness and musicality often associated with MOSFET transistors (which can be more fragile and prone to failure). In short, the METs deliver the best of both worlds. Each of these amplifiers has heat sinking specified to generously handle the dissipation requirements of its respective output stage, allowing safe, convenient in-cabinet installation if desired.
The D200, D300 and D400MKII each have both single-ended and balanced (XLR) input connectors, allowing easy connection to preamplifiers having either type of output. In addition, the D400 MKII offers a second set of inverting single-ended inputs, thereby allowing balanced operation in two different modes. Bridged mono operation, yielding substantially higher power output, is also possible with each of these three amplifiers, in either single-ended or balanced mode. Illustrated bridging instruction are included in the owner's manual for each model.
MSRP (US new retail)
|Power output||110 watts per channel into 8 ohms, 200 watts per channel into 4 ohms.|
|Power bandwidth||(-3dB points) DC to 150 kHz into 8 ohms.|
|Input sensitivity||1.5V RMS for rated output (25.5 dB gain) unbalanced or balanced.|
|Input impedance||150K ohms unbalanced, 300K ohms balanced differential.|
|Output regulation||0.07dB 8 ohm load to open circuit|
|Overall negative feedback|
|Rise time||1.7 µs|
|Hum & noise||Less than 40 µV RMS (117dB below rated output IHF A-weighted).|
|Power supply energy storage||124,000 µF total|
|Power requirements||105-125VAC 60Hz (210-250VAC 50Hz) 400 watts at rated output (110WPC 8 ohms), 640 watts at 200WPC 4 ohms, 800 watts maximum, 105 watts idle.|
|Other||Input polarity: Non-inverting at unbalanced inputs. Balanced pin 2+ (IEC-268).|
|Dimensions||19" (48 cm) W (standard rack panel) x 5¼" (13.3 cm) H x 11 7/8" (30.2 cm) D (front panel back). Handles extend 1 ½" (3.8 cm) forward of the 3/8" thick front panel. Output connectors extend 1" behind rear panel.|
|Weight||32.5 lbs. (14.8 kg) Net; 45 lbs. (20.5 kg) Shipping.|