Vinyl playback & ECL805 stereo PushPull amplifier

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Here I play a track called 'Intermezzo' from an easy listening mix album from 1980.
The sound from the loudspeakers connected to this amplifier was recorded with two microphones and synchronized with the video.
Schematic at the end of the video!

The amplifier is made on a metal Hammond chassis (sold as type: 1441-18BK3).
Tubes (or valves) are 4x ECL805, originally intended for use in television sets.
This tube combines actually two tubes in one glass envelope, a power pentode (max 7 watts anode dissipation) and a driver triode. The driver triodes in the tubes at the front of the amplifier are used as driver in the output stage and the triodes in the tubes at the rear are doing the phase splitting. The pentodes (front and back) make up the push-pull output stage which is cathode biased mostly class A and are in ultra linear operation. There is global feedback applied but no more than 6 db I estimate... this is done to extend the low frequency response. The feedback is calibrated to maintain perfect square waves without spikes.

More on the other equipment used:
Loudspeakers: Yamaha NS-1000M
Turntable: Technics SL-1200 MKII with Nagaoka MP-110
Category
Audio
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