PIMETA resistor R3 and R5 values question?

[syyuen]

I am going to build my PIMETA, I have read tangentsoft's website many times,
and search a lot of useful information from this forum.
But I still have a question on resistor selection.

From tangentsoft's website, it said R5 value should be 5x to 10x to R3.

Quote:

The outer loop's resistor values should be lower than the inner loop's values. As a rough rule of thumb, make R3 five to ten times lower than R5.

but from the PIMETA's schematic, R3 is 1K and R5 is 3.32K, it is less than 5x.
should I follow the rough rule or stick the schematic values?

 

[mono]

I'm wondering if it should've read "make R4, 5 to 10 times lower than R6"

Why not use the default values? Those are the ones I'd expect most people use and are those felt best compromise by the designer.

R3 and R4 though, set (have by far the most influence over) the gain so you might consider that most people find gain of roughly 2-4 optimal for low-Z cans or 3-6 for higher Z, if not higher for crossfeed support. Personally, I found the easiest way to go was putting a DIP socket on the R3 & R4 positions on the PCB so you can swap those resistors as desired.

 

[syyuen]

Thanks for your reply, now I understand that the default values are from experience,
but the "rule" is from theory. I know what to do.

I am going to put a DIP socket on those resistor positions too,
thanks for your gain suggestion.