Hamptone LCMP - Underbiasing the amp

Howdy-
I have emailed Scott Hampton about this question, but I haven't heard back from him. I get the impression he's a very busy fellow, so I thought I'd bring it to the Lab.
Here is a link to the schematic: http://www.hamptone.com/figure1.htm

Senor Hampton mentions in the mods/improvements section of his Tapeop article http://www.hamptone.com/tape_op_art.htm about this preamp that increasing the values for R's 2 and 5 will cause the amp to saturate more quickly. He goes on to recommend that any changes to these resistors should be "slight." R2 is 2.1k and R5 is 3.01k in the original design.

Would increasing the values of these R's to 3.01k and 4.12k respectively be a slight increase? Too much? Not enough to matter? I would just go with trial and error (mostly error probably) but as these components connect Pin3 to ground and Pin8 to ground my layout has them in kind of an inconvenient place for swapping them out.

Any help is much appreciated.

"Adjust the bias point, for fun. Changing R2 and R5 sets the "bias" of the two gain stages. Making these resistors bigger under-biases the amps, reducing gain and headroom. The benefit is the amps saturates very quickly and can sound really good on vocals/percussive signals. Making these resistors smaller takes the amp past the linear operating point and in general just makes it distort in a sonically displeasing way (lots of odd harmonics). The design shown under-biases the gain stages slightly from the optimum linear operating point. It’s a good tradeoff point between accuracy and tube "color". The totem pole follower works best when the dc voltage going into the Grid of V2 ½ (pin2), is roughly B+ / 2. So adjustments to R5 should be slight." Perhaps you could use a 1k5 with a 1k trim pot for R2, and a 3k2 and 1k trim pot for R5. Or change R3 and R6.

Thanks Walter! I have to admit that I don't really understand the whole biasing thing. I'm taking a class later this month on tube guitar amps, so I'm hoping to have a better handle on it then.
Is your suggestion about replacing R2 with a 1K5 and a 1K trim pot (and a similar approach to R5) in the interest of bringing that value up to a max of 2K5 with the trim pot for tweaking?

Thanks again.

A couple threads that contain volumes of information about tube biasing in mic preamp designs.

WCF output stage biasing:
http://www.groupdiy.com/index.php?topic=3452

Common Cathode biasing, and discussion of Cathode Follower vs. Plate out:
http://www.groupdiy.com/index.php?topic=12637

The values I suggest are for no particular range, but to get an idea of what that range will do. You could figure out the math for the circuit and determine the optimal range, but sometimes you got to shoot from the hip to get results. Thanks for the links, I have some reading to do.