27 March 2021

GRUNDIG Monolith 190 (1980) - Active Sound Wall

 

active loudspeaker

The first Laboratory Refence prototype of a 190 cm tall and 65 cm wide active soundwall was presented by Grundig at the 1979 Funkausstellung in Berlin. Due to large public interest a commercial model was released in 1980, this was the Grundig Monolith 190 Active Sound Wall, work of Dr. Arnold Glaab. The loudspeaker uses a system of three sets of vertically arranged speakers. It features 8 twin-series-parallel bass speakers, 7 series-parallel dome midrange speakers and 7 series-parallel dome tweeters for a 22 speaker wall of sound driven by 4 dedicated built-in power amplifiers. Each amplifier works in a frequency range determined by the active crossover network. Total power of a loudspeaker is 160 W nominal - 250 W music power (short term) while the frequency response is 20-25.000 Hz. The loudspeakers have to be connected to a pre-amplifier such as the Grundig XV 7500 which is capable of driving two sets of Grundig active loudspeakers. Each loudspeaker measures 68*192*46 cm, weighs 83 kg and the left and right loudspeaker are built in a mirror image speaker arrangement. Original sale price was 2800 DM per speaker.

active loudspeaker

active loudspeaker

active loudspeaker

active loudspeaker

active loudspeaker

active loudspeaker













21 March 2021

20 March 2021

Accuphase P-800 (1988) - Balanced Stereo PowerAmplifier

power amplifier

The Accuphase P-800 is a Balanced Stereo PowerAmplifier. Completely balanced powerful output stage consisting of two sets of 7 parallel push-pull transistor pairs, outstanding low-impedance drive capability, separate power supplies for left and right channels, balanced input.

The impedance of loudspeakers on the market varies considerably, ranging from about 2 ohms to 16 ohms. With a direct-coupled amplifier, driving such a wide impedance range with equal aplomb is almost impossible. An output stage designed for optimum performance at 2 ohms will deliver less power into 8 to 16 ohms. Conversely, the performance of an amplifier optimiozed for about 4 to 8 ohms suffers at 2 ohms and it will not be capable of driving 1-ohms loads. The P-800 incorporates a special design to deal with a wide range of load impedances. The applied voltage of its output devices can be switched to a lower value, to provide the high current capability required by low-impedance loads. This results in a truly amazing guaranteed rating of 600 watts into 1 ohm and 400 watts into 2 ohms, with undiminshed sound quality. To achieve such stunning performance the output stage of each power unit employs two sets of seven parallel push-pull pairs of wide-band transistors with a maximum power dissipation of 130 watts each. This amounts to 14 pairs or 28 transistors per unit, totaling a maximum powe dissipation of 3,6 kilowatts. These truly astounding figures testify to the no-holds-barred Design approach of the P-800.

To let you monitor its performance, the P-800 incorporates two symmetrically arranged analog level meters. The output meters are large analog meters symetrically arranged. They can directly read the output power in decibel units over a range as wide as from -60(0.0004 watts/8ohm) to+3 (800 watts/8ohm) dB. The meters can be activated and deactivated ot the illumination of the meters can be turned on or off by a switch. Except for the power switch, all controls are located behind a hinged subpanel door in the lower section of the front panel. The panel is finished in brushed gold aluminium, giving the P-800 an appearance of simple elegance. The visual appeal of the amplifier is further enhanced by the side panels made of exquisite persimmon-wood.

The beautiful and simple elegance of this amplifier's external appearance belies its awesome performance. But when turned on, it speaks unmistakably through music. Technical data: Continuous Average Power Output (20 to 20,000 Hz) Normal load operation (THD 0.01%) 600 W/ch 4 ohm, 400 W/ch 8 ohm, 200 W/ch 16 ohm | Total Harmonic Distortion 0.01% with 4-16 ohm load | Frequency Response: 20 to 200,000 Hz +/-0dB for rated output |  Damping Factor: 200 | Signal to Noise: 125 dB | Dimensions: 481*239*489 mm | Weight: 47.2 kg. 


power amplifier

power amplifier

power amplifier

power amplifier