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I ordered several - having procrastinated on VFE projects, there were several I was interested in. But I procrastinated too long and the Mobius Strip sold out! No matter, I have way more than enough to keep busy. Thanks Brian for doing this.

I bought a few ICL8038 function generator chips on ebay and they work. I have even made a synth VCO with one. It's not a direct replacement for the XR 2206 but you can find function gen circults that use the ICL8038.

I was leery of buying these as it broke my rule of "don't buy formerly out of production parts on ebay," but there are some current production ICL8038 generator kits on import from Asia, so I thought they might not be duds, and they're not. I'm not sure if they would meet every spec of the originals, but for an audio application they seem to work.

That's really cool.  There is a lot of mad scientist lab equipment heritage in this one.

I'm also relieved that the OP says "including a toddler for scale" and not "for sale" which is what it looked like when reading too fast.

To take a couple of real world orders of mine, this might mean I can't buy a single part from China for $1.29 + free shipping (which seems unfair to US sellers and the USPS). But I don't think it would affect that one can order $90 of parts from Tayda and have it shipped DHL for $9, which is still inexpensive. Requires planning ahead to consolidate orders and reduce packaging, which isn't a bad thing overall.

Nice font!

Also, style points for SMD on eyelet board.

I'm not near a guitar right now to try it out, but how about this one: https://tabs.ultimate-guitar.com/tab/the_rolling_stones/jumpin_jack_flash_tabs_175610

In particular there's a bar labeled "Guitar 1 and 2" at the end of the Intro, and that repeats under Verse 1. It is shown on frets 2 and 4 of the A-D-G strings, and is the "do-do, da-da-da, da-da-da" riff that instantly sounds like Jumpin' Jack Flash (IMO).  You might find it easier to play on the 7 and 9 frets of the E-A-D strings.

I'm a terrible guitar player, and my strategy is usually to practice that one characteristic riff to get it right, play the chords in rhythm, and let the more complex details slide.

Clearly, your voltages on IC3, the charge pump, are correct but the voltages on IC1 and IC2, the op-amps, are mostly wrong.

Pins 4 and 8 on the op-amps, which are the Vsupply pins, are fine.  However, notice that pins 3 and 5 of IC2, the second op-amp, should be connected directly to Vbias. Vbias should be about +4.5V. However, your pins 3 and 5 of IC2 read 0V.  This suggests that you have a problem which is grounding the bias rail. It's not clear whether the problem is in the components that generate Vbias, or whether you have something touching the bias strip (solder bridge, component in the wrong place, etc). But that's the first place you should look.

Pin 3 of IC1 is also connected to Vbias through a 1M resistor, so it's possible that this is also causing the problems on IC1.  In any case, a mis-biased circuit will generally sound horrible, so that's probably what is wrong.

As always, it's possible to figure out a lot about a circuit just by thinking about what the voltages are, and what they should be, starting with the simplest connections on the schematic (here, pins connected directly to Vbias).

Has anyone checked that it renders okay in Lynx?

Great question!  It depends on what you mean by acceptable:

So, here is what I do. uF caps don't carry audio. Film caps do. So I would take the first film cap in the audio path which looks like a 22n, and make it a 220n, then I would do the same thing to the last film cap. I've never done this with overdrives, but I have done it with filter pedals.

That's what I thought as well. C12 it's a 22n and looks to me at least like it's making a high pass filter with r10 @ 723Hz. Or am I missing something?

C12 is 22nF and R10 to ground is 1M.  That makes a corner frequency of f = 1/(2pi R C) = 7.2 Hz. It shouldn't have any effect on audible signals.  Sometimes the first and last coupling caps don't filter out audible bass.

BTW, I have read the datasheet for the LM308 op-amp a few times and have never persuaded myself that its slew rate or gain-bandwidth are so low as to make a difference at guitar frequencies (up to 5 kHz or so).  The Rat circuit just kinda sounds like a Rat. I think if one wants something that sounds different, maybe a DOD 250/MXR Distortion+ ?

It's possible that you set the volume trimmer based on the guitar into the delay, and then when you put another pedal in front you get the volume back, so it seems like a boost.  If this is the case (and I'm not sure from the information provided), then a high-impedance buffer at the input might help, but you have to be sure that it's a really high impedance.

To try to make it clear.
I plug a Standard strat straight into the Sea Urchin and I have unity gain when the pedal is engaged. Now, I have a Fulltone Soulbender Clone that I have been playing and also a Fuzzface Clone. With both of them I set the volume pot to match my clean signal in terms of volume. The problem is that, when I have any of the fuzzes engaged and turn on the Delay pedal there is a huge volume boost. Could this be a mismatch of the output impedance of both fuzzes (500k) and the Sea Urchin input impedance(180k)? Also, isn't R1 (1M) setting the input impedance?

R1, the pull-down resistor, doesn't set the input impedance (I guess it's an upper limit to the input impedance). For an inverting op-amp, the + input is held fixed at the reference voltage, which means that the - input is also fixed at the reference voltage of +4.5 V, because op-amps try to equalize their inputs. That means your input is connected by a 180K resistor to the fixed +4.5 V. So the input impedance is 180K. The link I posted above to radio-electronics.com has a pretty good explanation of this and how it differs for a non-inverting op-amp.

The output impedance of a pedal like a Soul Bender or Fuzz Face that has a volume pot on its output is a little complicated, because it depends on where in the pot's rotation you have it set. The 180K input impedance winds up being in parallel with the lower leg of the volume pot, that is it's in parallel with pins 1 and 2 of the volume pot. (There is probably a coupling cap between the volume pot and the Sea Urchin input, but for AC audio the cap passes signal.) This can make the volume drop when you switch the second pedal on, which is not what you are reporting.

What's a little out of the ordinary is that you put in a trimmer to adjust the output level. I am wondering, of course I don't know, if the Sea Urchin's natural state with just a guitar plugged in is to drop the volume, you adjusted the trimmer to take that out, and now when you put the fuzz pedal between the guitar and delay, it's boosting.

Nice artwork and I dig the unusual pot layout that comes from turning the board sideways.

Ah but the Electra distortion was never a pedal! Its clones may be, but the title specifies "pedal effects", and that circuit was just shoved into a guitar's body cavity!

/ultimate_pedant 

You can totally step on a guitar.

/punker

Sean from Lovepedal called and asked me to vote for the Electra Distortion.

Page 8 of the data sheet, left column: explanation of how the circuit works to use switches on a high-frequency cycle to charge an external capacitor and prevent it from discharging, and discussion of technical considerations of how the switching transistors are biased to avoid latching up. Page 8 right column do's and don'ts, point 7: "User should ensure that the output (pin 5) does not go more positive than GND (pin 3). Device latch-up will occur under these conditions."

In the voltage doubler application, we aren't using the V_out (pin 5) that is used for the negative voltage output. The do's and don'ts clearly suggest that it should be tied to ground. If it floats and is not tied to ground, the circuit may work, until something unexpected happens and it latches up, and then it won't work (and the user will probably say "My charge pump IC is bad," mis-diagnosing the problem).

A 2N3904 is about the most common transistor in existence. It's going to either work or be DOA; the most likely variable is the gain, which matters in some circuits and not that much in others. It is also likely that most transistors you could buy are made in China, or if not, somewhere else nearby in Asia. The benefit of ordering from Mouser instead of some random ebay seller is that you get a vetted supply chain and a supplier whose reputation depends on 99.99999% reliable parts.

The Big Muff hs a reputation for sounding a little different depending on what parts you put in it, so it's possible that two different batches of transistors would sound different depending on their gains, without any judgment about their relative "quality" or tightness of spec.

For really generic parts like 2N3904, resistors, silicon diodes, basic op-amps, etc, generic sources are probably fine, especially for stompboxes. When you get into rare (unusual ICs, bucket brigade delays, etc) or highly variable parts (JFETs), that you should beware of too-good deals on places like ebay.

I don't have a Peak DCA, but do have a "GM328" cheapo parts tester that can measure values of passive components, transistors, and diodes. These cost only about $10 on, yes, ebay, and can be very useful if you want to sort parts.