The new owner of the EL6471 bought this via an auction website and came after delivery of the equipment to his amazement discovered that the thing worked flawlessly even after 55 years!
Meanwhile on the Internet for several videos appeared when the amplifier 'in action' can be seen, although only output up to 250 W in connection with the carrying capacity of the connected speakers, but otherwise in full glory, with an ammeter for the anode current and the large mercury filled tubes rectifiers blue light in the rhythm of the music.
The EL6471 was originally designed for use in large stadiums and concert halls. There was only a limited number of copies manufactured by Philips. The applied power tubes are QB3/750 that were actually designed for use in RF transmitters. According to the leaflet with the product of the EL6471 there were also versions of 2 kW, 10 kW and 20 kW.
Philips EL6471 technical characteristics:
• 1000 watt Class-B power amplifier• Driver: 2 x EL34 (6CA7) as a cathode follower, DC-coupled to the output tubes
• Balanced input
• Frequency Response 25 ... 15,000 Hz + / - 1 dB
• Power connection: 3-phase (220/380V)
• Anode Voltage: 3.200 V
• Anode current: 250 mA (full level control), 50 mA (quiescent current)
• Year of construction: 1955
• Dimensions: 520 x 690 x 580 mm
• Weight: 142 kg per channel
The proud owner of the EL6471 know additionally reported that the amplifier has a beautiful transparent and dry 'sound' and also produces low distortion and good damping factor. For the first test was a 15 inch Eminence speaker 250 W in a bass reflex enclosure connected, which is not the full power could be exploited. But this combination produced an enormous sound.
On YouTube by many viewers of the videos with admiration and astounded. Some would immediately order two, with even the possibility is suggested to put them on an iPod / iPhone to connect.