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Is anything else connected to pin6 besides the LDR...like a delay pot?

Some of those voltages likely have an easy explanation: DMM's can cause an issue when measuring voltages on the inputs of some ICs if there is an internal resistance present between your leads - what happens is the leads themselves act as a voltage divider and end up reducing the measured voltage (iow, the act of measuring affects the voltage). I've had this very thing happen before on one of the multimeters I owned. I would make sure you have used a 1M resistor on R4 and not something like 10M, but I think the former explanation is the likely case.

The gate voltages on the FETs could come down to individual specs on the devices themselves, whether its their VGS ratings or some other spec. The FETs are being used as variable resistors here so as long as your octaves are triggering then I would not be concerned.

IC7 pin13 is a little more concerning. That pin is untied to anything. So there are a few possibilities here: 1) I measured that pin incorrectly and there is some internal resistance between pins 13 and 14 in the actual IC which would cause a reading of VC there 2) there is continuity between those pins either in the traces on your board or via a solder bridge or 3) you have a bad part. What I would do there is unplug the circuit, remove IC7 and if you have a continuity checker, test pins 13 and 14 in the socket to see if there is a connection. If so, check the traces and pads underneath for a board error or solder bridge. In the end, it may not matter if there is because like I said pin13 is not used for anything. As long as your IC is not getting really hot then you are probably fine.

After a couple months of smooth sailing using the new Flats system to ship international orders there seems to be a major snag. Over the last week or so I've been getting packages returned as undeliverable. It seems that the sorting facility that is relabeling the shipping information before sending packages out of the States is not copying the full address. I've had several come back with no street name or number on them. I have no idea why they are doing this or how they could not have noticed the problem. But it most definitely is a problem and a rather expensive one for me to have to re-ship items.

Anyway, over the last several days I have been editing send-to addresses to as few lines as possible to see if that gets them through. If that doesn't work, we may have to go back to regular 1st Class shipping on everything (no problems there because it doesn't require re-labeling). That would suck since it costs twice as much, but would be better than having to deal with this situation.

In any case, if you have been waiting more than 2-3 weeks on a package and are not seeing updates through USPS.com then you might be the unlucky winner in this lottery. Feel free to email me if you have concerns. I will re-send the package (at no charge obviously) if there is no delivery after 30 days from shipment.

Like Jon said, this is a very atypical problem - pedals generally don't just quit working after a successful fire-up. It could be a power or parts problem as mentioned. Another possibility is a missed solder joint (or bad one). I've had quite a few builds work intermittently due to a missed solder joint (just last week, in fact).

I can relate to your frustration, though. Hell, at least 1/2 of what I build doesn't work the first time. But, it's usually a design mistake I've made on prototype boards. The more time you spend now trying to figure out what's gone wrong will pay off later with future builds (no matter who's project you are building).

The low ESR are preferred but regular 22uF will work fine. The Merman is the only klone type build I've used low ESR caps in.

J176 might work as a sub which Mouser has in quantity. Don't have any here to test, though.

So, there are a couple mods I did on this circuit to try and squeeze as much gain as possible out of it. But, it seems like I went too far. The two changes are in the first and second gain stages.

To eliminate the problem try reducing R8 from 270k to 220k. If that solves the motorboating stop there. If not, either 1) replace R16 with 150k or 2) change the Gain pot to 100kB and remove (or clip one lead) of R16.

My apologies for the hassle. Please let me know what you find and I will update the build doc accordingly.

Yup. I've got a decent quantity of each and enough where I can offer the 3-bundle for a discount. The circuits are really great and a bit easier to build than the older designs (everything is integrated on one PCB).

I should have my builds to show soon. I've just ordered enclosures for them. Pedalparts plus offers pre-drilled ones specifically for these projects, too.

Put them on the bottom of the PCB.

A bit of a misunderstanding - there is no expression mod for the Mandroid. There is an external trigger option you could use in place of the "Splode" control but the idea was for maybe an LFO or capacitive touch interface, not a pot (in fact, connecting a pot would do nothing).

If you want to use an expression pedal type control with the Mandroid, then I would use it in place of the WARP control instead (same pot value). That might actually be quite cool.

Again, the J1 part of the J1_ALT label is not meant to indicate the location of the tip connection...J1_ALT is the label for both tip and sleeve (similarly with J2_ALT).

J1 ALT and J2 ALT are the labels for both tip and sleeve connections. "J1" of the the "J1 ALT" isn't placed over the exact pad that connects to the jack tip. The wiring diagram shows which connections the pads cover (square pad is tip and round pad is sleeve).

I believe the labelling for the alternate switching inputs and grounds on the bottom side of the board does not match the labels for the holes on the top side.

For example -- the top right side of the switching board has "ALT" next to the edge of the board.  If you look at that same hole on the bottom of the board it is labelled "J2"   

The top left hole on the switching board is labelled "J1" but if you look at that hole on the other side it is labelled "ALT"

Think about it again. Look at the images below - one shows the top of the PCB and one shows the bottom (as you would see it in your hands). J1 and J2 are in the same place, regardless. The ALT pads are for wires and the J1 and J2 are for PCB mounted jacks.

How are they inconsistent? I'm not seeing it.