Second set of eyes on this please...

[Barcode80]

So, I liked RG's layout for the Big Cheese, but I didn't want to mount the switch on the board because i wanted a little more layout flexibility. So I had a crack at making a layout in Express PCB. The nodes check out as far as I can tell from the Express PCB schematic link, but I want someone else to look it over. Can some of you compare the layout to the schem (http://www.generalguitargadgets.com/diagrams/geo_great_cheddar_v6.pdf) and tell me if it looks good? Part numbers should line up. The only difference is a added a couple of resistors to the output section and tweaked a couple values to get more volume. Thanks in advance!

[Dan N]

One vote for AOK.

[Barcode80]

Thanks! by the way, the unmarked vacant holes that appear across from one another are where jumpers go. I usually avoid jumpers, but I like the neat layout of the components i ended up with by using the jumpers.

[JKowalski]

Thanks! by the way, the unmarked vacant holes that appear across from one another are where jumpers go. I usually avoid jumpers, but I like the neat layout of the components i ended up with by using the jumpers.

Nothing wrong with jumpers

Professional PCB designers just disguise all of theirs by using 0 ohm resistors (SMD or axial)  I always think sacrificing a good layout because of an aversion to a couple jumpers is ridiculous.

[Nitefly182]

Thanks! by the way, the unmarked vacant holes that appear across from one another are where jumpers go. I usually avoid jumpers, but I like the neat layout of the components i ended up with by using the jumpers.

Nothing wrong with jumpers

Professional PCB designers just disguise all of theirs by using 0 ohm resistors (SMD or axial)  I always think sacrificing a good layout because of an aversion to a couple jumpers is ridiculous.

I always thought it was an ego thing for most guys who dont like them.

[JKowalski]

A question, why does eagle (never used it) do ground fills but only connect the ground trace to the fill by small bridges by the pads? Why not just fill in the border around the ground trace?

[rustypinto]

A question, why does eagle (never used it) do ground fills but only connect the ground trace to the fill by small bridges by the pads? Why not just fill in the border around the ground trace?

Thermal relief. That plane often makes for a good heat sink making it difficult to solder to.

[Barcode80]

yep. also, just an fyi, this was done in express pcb, not eagle. but they generally look the same. I'm wiring up the layout now, if verified I'll post a project file.

[Barcode80]

hmm, well it's all wired up. I've built this circuit before, but this time I'm on my 3rd board, and none have worked. I tried RG's layout (which I've built before), my own DIYLC layout, and this one. I'm losing signal right at the first transistor, and I'm at a loss as to why. ANy thoughts?

[Barcode80]

Strange voltages on Q1. I've also replaced the transistor with a new one. ANy thoughts?

E - 0
B - .06
C - .62

[Dan N]

If you have the correct values for R5, 6, and 7 and have the jumper in place connecting to R5, I can't see why it would do that.

[Barcode80]

SUCCESS!!! R8 was the culprit. I had accidentally soldered in a 470K (!) in place of the 10k. This was mis-biasiing Q2, which was screwing with Q1's voltage. I'm fuzzing away now. COnsider the layout verified, I'll post a project file in the next couple of days. Thanks guys!