03-10-2017, 03:14 PM
The schematic of the code 122 and 125 should be very close.
The 35Z5 and 35Y4 are electrically identical as is the 50L6 and 50B5, the difference being the base and physical construction. Just look up the corresponding tube type in a manual or online and relate the pin connection numbers of each type to the schematic.
When the field coil speaker was replaced in the later production 125, the field was most likely replaced with a resistor of comparable value.
The 35Z5 and 35Y4 are electrically identical as is the 50L6 and 50B5, the difference being the base and physical construction. Just look up the corresponding tube type in a manual or online and relate the pin connection numbers of each type to the schematic.
When the field coil speaker was replaced in the later production 125, the field was most likely replaced with a resistor of comparable value.
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