Lizzy (aka Serendipity)

[gtr2]

Been working off and on with this one for about two months.  Its my second build (first one a byoc).  I etched the board thanks to madbeans great layout, ordered parts and the rest is history...

All jacks top mounted, had to dremel the lid inside lip to get it to fit flat.  Can't even tell when the lid is on.  It was time consuming with the layout/drilling as I had to make sure that nothing would interfere with each other.  Things are tight at the top, I almost didn't think it was possible with the pots and jacks all in the same area.  Using a 125 case would have been easier, but I wanted it in a 1590B. It took some tight spacing to get a battery in there but it worked.  Sounds nice, a but little less gain than expected.  I have no personal exp with a real zen drive.  Painting was a pain, kept getting little things going wrong.  I tried to be neat since I knew I would post the guts  

Constructive comments welcome..still learning.

[stecykmi]

VERY impressive, especially for a second build

[dcribbs1412]

Congrats on a very nice build
on with the next one

[madbean]

That's a cute picture. Makes me think it is a robot.

That is a VERY nice second build. Keep up the good work~!

[gtr2]

Guess I can enter it in the competition then...   I was hoping to enter something but I'm moving and it took me longer than expected to finish this pedal.  Maybe next time round!

[gtr2]

After using this pedal for a few weeks and checking out some you tube clips from that guy that wears the cowboy boots, I'm thinking for some reason my clone has less gain than it should.  I have to have the gain and voice the whole way up and I get some nice crunch, but single not lines lack the "bite" I hear in the clips.  I should note this is going into a blues jr (jensen speaker) set to a nice clean tone and a gibby les paul w/ burstbuckers.  The amp is not at the edge of breakup.  I understand this is in no way a higher gain pedal but it seems a little mild next to the clips I've heard.  Thanks.

[madbean]

I would either increase the value of the gain pot, or reduce (or eliminate) the number of diodes in the feedback loop. Either of those will give you some more gain.

[gtr2]

How would increasing the drive pot value increase the gain?  I thought that when the pot was fully "open" there was no resistance to the feedback loop.  I'm still learning all this stuff so this may be way off.  Help?

[madbean]

You have it backwards. Fully open means there is little or no resistance across the feedback loop. The gain of a feedback loop (using the non-inverted input)  is calculated by (R1*R2)/(R1+R2), where R1 is the resistor off the inverted input of the opamp stage and R2 is the resistor in the actual feedback loop. When you turn the gain pot up, you are increasing the resistance, and therefore you increase the gain.

[gtr2]

Ahh that makes sense.  Thanks for your help.  I'm still really struggling with understanding how these circuits work.  I guess I'll try a 1 meg pot.