Unch Na 6p3s I 6n8s
Completed repair on another Antique sounds 1006 SET power amp. 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. 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. 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. 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. Imho, the 2nd stage 6sn7 cathode followers can be taken out altogether i do not see any compelling reason for putting it there except to say that Antique sounds might have truckloads of 6sn7's.but hey, this is not my amp so i will just let it be. Sorry for the long post.
Main article: Receiving tubes have heaters or filaments intended for direct battery operation, parallel operation off a dedicated winding on a supply transformer, or series string operation on transformer-less sets. High-power are directly heated; the heater voltage must be much smaller than the signal voltage on the grid and is therefore in the 5.25 V range, drawing up to hundreds of amperes from a suitable heater transformer. In some valve part number series, the voltage class of the heater is given in the part number, and a similar valve might be available with several different heater voltage ratings.
Mp3 download. PAIR of USSR Soviet Full Range Speakers 10GDSH-1-4 (10GD-36K) 8 inch, 15W, 4Om. 10x 6P3S (6L6, 5881) REFLECTOR, USSR (New, NOS, from 70-s).
Tube bases and envelopes [ ]. Main article: Abbreviations used in this list [ ] • ST – Shouldered tube • GT – Glass tube • MT – Miniature tube, such as or • FL – Subminiature all-glass elliptical body and flat bases with long, inline 'flying leads' (pigtails) that are soldered into the circuit • SL – Subminiature all-glass elliptical body and flat bases with short inline leads that can be soldered or can be mated with a special socket. (Flying leads can be cut short to fit into inline sockets.) • R8 – Subminiature all-glass round body and base with 8 flying leads or stiff pins arranged in a circle Numbering systems [ ] North American systems [ ] RMA system (1942) [ ].
Main article: The system assigned numbers with the base form '1A21', and is therefore also referred to as the '1A21 system'. Main article: RETMA is the acronym for the Radio Electronic Television Manufacturers Association formed in 1953.
• The first character group is a number representing the heater voltage rounded to the nearest whole number; 0 indicates a. • One or two letters assigned to the devices in order of development. • A single numeral that represents the number of active elements in the tube.