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That's not just "test conditions". Overall noise is the result of voltage and current noise. Depending on the impedances involved, one or the other will dominate. Hence there will be circuits where the 4558 can be quieter of course.

The fact of the matter is, many guitar pedals are terribly designed in that regard. High impedance environments with old bipolar opamps put in haphazardly. Many EHX circuits come to mind. And the result of that is people jumping to simple conclusions without any understanding and getting wrong impressions about parts, but the problem is they are only used improperly.

Suffice it to say, the 4558 isn't a good part by today's standards, far from it. For the same price you can get a NE5532, which beats it in every way. But we're building guitar pedals here, so at least for distortion the ear might have to decide what you put in. Still, many circuits can be adapted to lower impedances in order to reduce noise, without changing the tone.

You need to switch to DC voltage. The wave in the display means you're measuring AC voltage. Look at the labels at the switch positions, there are two functions for each position. My guess would be you change the function with the orange button.

Deer is my favorite meat by far. Don't think I've ever eaten it fried in a pan, or actually even cooked it myself. So I can't comment on the smell of it raw  or while cooking. The way you would get it most likely served in Bavaria is like this, as a Ragout:



Or roasted like this.

I've never played the Pulsar. If you don't mind a really big box there is also the Love Wobulator for stereo. It has a couple more tricks than just plain stereo tremolo. I have a pcb for that if you want. It has four operating modes, and two separate LFOs, which are either square or sawtooth. From the website:

• TREM - both Left and Right move up and down at the same time, but with a "cross-over" effect where Left is low pass filtered and Right is high pass filtered.
• PAN - Left and Right move in anti-phase without a cross-over, akin to a normal "figure-of-eight" auto-panner.
• VIB - same as TREM but in anti-phase, creating subtle phase cancellation (and therefore pitch and volume change) effects.
• DUAL TREM - this again uses the cross-over but brings into play the second LFO. Left is now driven by LFO 1 and right by LFO 2.

https://www.freestompboxes.org/viewtopic.php?f=7&t=14396

It's a Tonebender style circuit using silicon transistors.

It's also rather crude and will only work for one polarity. Since particularly guitar signals can be very asymmetrical, depending on your expectations regarding the accuracy of the clipping indicator this circuit might not be good enough.
For proper and reliable detection you need a full wave rectifier.

I took the liberty to make a little correction there Jon.

low input impedance (not great for input stages) and occasionally... just doesn't work right in circuits.

Could you elaborate maybe? Never had any problems with it and I'm not aware why it would have a low input impedance.

OPA1642. Texas Instruments audio opamp. Rail to rail. Low noise. Phase reversal protection. Get some SMD adapter PCBs and A/B test against the 072 and your jaw will drop. $2

Yes, great part. When going for SMD there is also the OPA1678 which I am keen to try out. Also R2R, specced for audio and down to 5V and is 75ct in single units. Interestingly it is a MOSFET IC but manages to slightliy beat the OPA1642 in regard to noise.

Ideally you should always try to replace a BJT input opamp with the same type, and FET input with FET. Even though most "designers" of pedals probably have no regard for low noise design in the first place... For a BJT input opamp my usual choices are NE5532 and MC33078, for FET input just TL072 or TLE2072.

If you want to dive deeper into opamp fidelity here is a very thorough analysis of topologies and types: PDF.

Using this: https://www.mouser.de/datasheet/2/449/XC-600134-1212477.pdf

Primary side (left) in the schematic: pin 1 is signal, pin 3 ground.
Secondary side: pin 4 to the jack tip, pin 6 to sleeve.

I don't use Kicad, but that isn't software specific. Make a new layer, draw the lines, and include that layer when exporting the Gerber files in the mechanical/GML file. And make a note when ordering: V-scoring in the GML file.

Just put a voltage follower/buffer in front. Output is fine as is.

There is also the BE resistance of the transistor in parallel, which is much lower than that.

https://guitarscience.net/calcs/cecb.htm

Put in some rough values here, you will get less than 1k.

You also need to consider C4, which is probably big enough, and C6, which is too small if you want full bandwidth response. Soundwise, that might actually not be desirable. The low end is also for normal guitar very attenuated.

Something quite a bit rarer is a reply stating that, as long as your iron has enough oomph behind it and a tip that can physically transfer heat to the particular size part you have, technique is something that the person should work on.

It's really all that matters. I recently had to go back to my very first iron for a couple of days when my current JBC refused to work. It has temperature control via a simple thyristor adjusting the mains voltage. When I started out with electronics it was all I had, and I sucked, and I thought at least part of it was to blame on the iron. Now going back, I can work absolutely fine with it, really nothing to complain about its operation. Besides the 2-3min heatup time. The JBC is hot within less than a second, and I never want to use anything else again if I can avoid it. The slim handle, the vast choice of tips available and their durability are far superior of course as well. I have used the same three tips for over 7 years now.

The thing is, that with guitar pedals there are plenty of components that are temperature fragile, such as diodes and transistors.

That's a myth that just doesn't want to die. In almost 20 years of electronics I haven't managed to destroy a single part with hand soldering. Have you ever looked at reflow temperature profiles? Way more stress than even the worst soldering novice will cause the component.