Deadringer help

[insomniac2295]

So, I'm working on building a Bassdrive clone, which is almost the exact same circuit as the Fulldrive, save 4 caps. I've built a Bassdrive clone before using a layout from freestompboxes.org. However, after re-visiting this project I have noticed that the layout I used didn't have a 1K resistor (R2 in the schematic below) in the input buffer that the deadringer has.

My question is, what is the purpose of this resistor and would not including it yield any noticeable difference(s)? Here's the schematic which has been altered for the Bassdrive values (not by me):

[Matt]

 Delete

[midwayfair]

It forms a voltage divider with the pull-down resistor, as well as part of the input filtering with C1 and C2. You are unlikely to notice the difference by leaving it off, though it is a best practice to include it. Actually, the biggest difference will be that C2 will do even less than it already does, so you could save another part by leaving off C2. There's an analogous part at the output in R17.

Q4 in this design is confusing to me. The MOSFET won't work properly when the gate is connected to the drain without a series diode (like Q3 has). See RG's description here:
http://www.diystompboxes.com/smfforum/index.php?topic=38581.msg273665#msg273665

The Zen Drive and Bean's Sparkplug have it set up properly. It looks like the Fulldrive just uses MOSFETs in the pointless silicon body diode way (because otherwise you're only clipping one side of the wave at all), which is gate connected to source. You could save yourself some money and just use a 1N914 or 1N4148 in place of Q2 and Q3, because it'll be basically the exact same thing.

[insomniac2295]

It's funny you should mention that about the transistors and diodes. I've been following the bassdrive thread over at freestompboxes and someone posted an out of focus picture of their bassdrive MOSFET which uses the same board as the Fulldrive 2. On that board you can see what appears to be 2 germanium diodes connected to the clipping transistors. Upon further inspection of a more hi-res fulldrive, you can clearly see markings on the board for diodes.
Bassdrive:



Fulldrive 2:



One interesting thing is that this particular fulldrive has a resistor in the D9 spot. Others I've seen have a resistor there as well as D6 (also, 9 diodes?!). Anyways, it appears I shall have to socket some components to see what sounds best.
On another note, if one were to go off of the following layout, how could one alter the layout in order to accommodate for the extra diodes?

[ichilton]

Isn't that a 0 ohm resistor - i.e a wire link?

Ian

[insomniac2295]

Good eye! For some reason I didn't catch that. I usually just ignore color codes anyways since I'm semi-color blind. I just must have assumed that they were pale colors that I couldn't make out.