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RE: resistors value

Posted by Chip647 on March 12, 2017 at 10:23:05:
Yes, close enough is close enough for resistor values. Get familiar with Ohms law and use logic on loading resistors. The 1M resistor just sets the input load. 500K would work as well. The cathode resistor in the second section sets bias as part of the diodes on the grid. 1% variance of a 422 ohm resistor is 4.22 ohms which puts 430 ohms almost within 1%. 5% variance is generally tolerable.

I would not monkey with the cathode resistor on the lower 6922 section. That is a particular circuit that is serving as an active cathode load for the upper section. You are not going to get much an improvement at all, if any. The designer is obviously fully aware of the benefits of CCS cathode loading as they used it in the first stage and would have used it in the next if it was needed.