On Friday, November 4, 2016 at 2:49:16 PM UTC-4, N_Cook wrote:

Its not a tolerance thing, gold fourth band.
R67 and R66 are exactly the same resistor batch, the green of the heat
aged one is now not green, its value is now not 150R

You miss my point. Resistors drift, true. And the resistors in place seem to be undersized (operative word "seem") You intend to to replace them with higher-watt devices that are at the correct value. All good, so far.

But, I am asking whether the circuit itself may be tolerant of that drift - hence the question on band 4 - if any.

Peter Wieck
Melrose Park, PA