5/30/2023 0 Comments Unch na 6p3s i 6n8s![]() In the course of repairing this amps, i found out that there were 3 coupling caps in the signal path, compared to the original published schematics with only two, so i investigated and found out that the second stage cathode follower were converted to cascaded cathode follower to justify a third cap.i have never seen such a practice before and can not see any logic behind it, so i simply restored the amp to its original configuration.done away with one cap and a power resistor. You might be wondering what the 6L6gwb and the 6sl7 tubes are doing there, well, they are a voltage regulators that supplied low impedance power to the 3 6SN7's.the 6L6gwb is the series pass element and the 6sl7 tube is the error amplifier using a zener voltage reference at its cathodes. Topology of this amp is like these: 6SN7 srpp voltage amp input stage, buffered by a paralleled section 6SN7 cathode follower feeding another 6SN7 active loaded voltage amp that feed the 845 grid, the 845 is fixed bias at around 80mA for an idle dissipation of around 80 watts. To those interested, this amp is a single ended amp capable of at least 20 watts of output power.power dram from meralco is around 170 watts. 20 3hA 85A 100.Ĭompleted repair on another Antique sounds 1006 SET power amp. ![]() ![]() Because the card punch limits the number of availa.
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