Posted by Damir [ 220.127.116.11 ] on March 27, 2006 at 05:43:41:
In Reply to: 300B SE Project, Part 9 - E180F, E280F, D3a pentodes - triode connected posted by Damir on March 09, 2006 at 14:19:29:
On the E180F driver schematic, the cathode resistor R6=226 ohms is noted like three (parallel) resistors of 680 Ohms on pins 1, 3, 8. This is not correct - E180F has only two cathode pins, 1 & 3. The pin 8 is actually g3 and shield.
I actually used three 680 Ohms resistors on the pins 1, 3 and 6 - where pins 3 & 6 are connected together. I used "blank" pin 6 like soldering terminal, and forget about it - it`s better to draw a schematics based on datasheets, and not on (bad) memories...
In fact, it is better and simpler just to use two cathode resistors of 453 ohms, connected on pins 1 & 3.
In Part 11 we`ll see the complete and correct amp schematic + wiring diagrams and tube bases.
Here`s the corrected E180F driver schematic.
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