First pedal build, a klon clone, and it doesn't work

[ldornado]

Hey all, my first time building a pedal, and I was excited to try it out and - it tripped the power strip breaker. I check for shorts and don't see anything obvious, put it back in the enclosure and get a very low volume, muffled kind of sound.

I wasn't quite sure where to post this since it's a build for a klon clone which is a schematic that isn't available here. Hopefully this is an ok place...

1. Refractor from AionFx.com
2. Instructions: https://aionfx.com/app/files/docs/refractor_kit_documentation.pdf
3. I followed the intended layout 100% with the exception of not hooking up the optional 9V battery connection
4. I did not do any substitutions or modifications. I have however pulled a few resistors and replaced them to test if I broke them or not. I also removed the tantalum capacitor as I'm 97% sure I put it in the wrong way. I have replacements coming within the next few days.

In full transparency, I tried keeping the soldering iron (750f) on the pad for no more than 2-3 seconds, but there were probably more than a handful of times I wasn't that good.
5. I'm not sure if it's a positive ground circuit or not, and the docs don't mention this
6. The first time I plugged it in, the LED came on briefly and the power strip breaker was tripped. I checked all the connections, gave a little more clearance on the pots, trimmed some solder points closer to the board, and plugged it in again. The LED comes on when expected, bypass works, but when the pedal is engaged I hear a very, very low and muffled output.

ICs:
My measured IC voltage, with correct voltage specified from a 9.68v supply in parentheses:
IC1
4.38    (4.92)
4.38    (4.92)
1.02    (3-4)
0       (0)
4.32    (4.90)
4.38    (4.92)
4.38    (4.97)
9.41    (9.86)

IC2
-6.57   (4.96)
3.92    (4.92)
4.33    (4.91)
-9.39   (-9.49)
4.32    (4.91)
-6.17   (4.92)
-6.56   (4.87)
-7.21   (17.99)

IC3
9.41    (9.86)
5.48    (5.02)
0       (0)
-3.91   (-4.66)
-9.39   (-9.49)
4.59    (4.95)
4.18    (6.35)
9.41    (9.86)

I measured all the resistors, and every one closely matched the marked resistance save for the following:
R26     68k, but alternates between 68k and 0 when the footswitch is engaged. I'm assuming this is expected?
R17     27k, but measures 8.2k on the board
R19     15k, but measures 10.9k on the board
R22     100k, but measures 53k on the board. I pulled this out and it tested at 100k. Not sure why?
R24     100k, but measures 53k on the board

Because of R26 and R22, I'm questioning whether these results are interesting or not. Are the on-board resistances being affected by circuits in ways I don't understand, or are they legitimately bad resistors or resistors I damaged?

At this point I'm stumped. I'm placed an order for a new tantalum capacitor and some resistors to replace the ones I pulled to test. My open questions:

- What caused that powerstrip trip the first time I plugged in? The docs mention "After you've finished soldering the pots, clip the leads as close as you can to the main PCB. This is more important with the two uppermost pots because the input/output PCB overlaps them and you need to avoid any of the components shorting." This could have happened, but I tried being careful with it. Is there anything I can stick between these long-term to ensure I don't short anything?
- The 3PDT switch didn't have any directions on which way was right side up. Did I mess this up?
- Would the tantalum capacitor being flipped cause all/any of the above?

Thanks in advance, it was a lot of work and really demoralizing to get to this point, but I'm determined to figure it out eventually!

[idy]

That is an ambitious first project. Lots to learn.
It is confusing to measure resistance  when a resistor is in a circuit. First, you may or may not know, you can't measure resistance when power is on. Second, when other resistors in "parallel" to the one you are measuring you will see smaller R. If the two Rs are equal, you will measure half the individual value. Otherwise its (R1xR2)/(R1+R2).

In the cases you mention, there are in some cases, R with Capacitor in Parallel. Once a cap is in there you will see values that start low and then, as your meter charges the cap off, level off. So theses measurements are not very useful. Do the color code on those suspicious Rs look right?

The bad voltage on IC1 pin 3 is alone enough to cause your problems. It should be the same as pin 2 and 3 although your meter may "load" it and make it read a little low, but still close. Double check R2; one end should have mid voltage (your 4.32). The other end apparently does not... If you remove the IC from its socket (you did use sockets?) and power on, do you see that mid voltage at pin 3? You should. Double check solder on R2 and look for shorts around R2 and pin3.

[ldornado]

It felt too ambitious as I dove into it for sure - I'll be getting a simple fuzz to actually learn the types of things you're talking about. Great information, most of which I didn't know, so thank you!

Thankfully the kit used clearly labeled resistors, and I measured every single one with the only "deviants" being the few that I listed. I'll go back and figure out if they're in parallel, but the fact that I pull some of them and they read the label value kind of answers that question.

For now, I'll wait until my new cap/resistors come from Mouser and once those are in, I'll focus on getting that IC1 to work right (yes, I used sockets). I'll report back either way - hopefully with a good sounding pedal!

[duck_arse]

welcome to the forum. don't feel bad about picking a klone as your first pedal build, it happens far too often around here.

we can't see what you can see - show us, please, some photos. nice and clear so we can read colour bands, and solder side so we can see joints, and the off-board things like jacks so we can see your ground connections.

your IC2 is way off, whichever set of readings is yours. and the footswitch lugs are flat left to right when the switch up and down are correctly upped and downed.

tripping a powerboard indicates something very much more wrong than a backward tantalum capacitor [in an audio circuit]. some information about your supply might help, also info about your power strip. we just love info.

[ldornado]

Picture gallery: https://imgur.com/a/3Z5NNNh

Power supply: BOSS .25A that works fine for other pedals (https://i.imgur.com/5rb9X9T.jpg)
Power strip: an old Belkin (https://i.imgur.com/W3KEruZ.jpg) that had some other stuff plugged in at the time like an amp and a dehumidifer. Didn't trip again so might've just had too much plugged in and this is a red herring.

I removed C16, R22, R27 to test them. Will put those back in in the next day or two. Yeah, some big solder points as I started with a generic tip and "standard" solder before realizing I needed a smaller tip and thinner solder.

Top view, main pcb: https://i.imgur.com/YOinmR5.jpg
Bottom: https://i.imgur.com/i3rqJHc.jpg
Side, to see under pots: https://i.imgur.com/20eHAg1.jpg

Footswitch top: https://i.imgur.com/NuDMW8T.jpg
bottom: https://i.imgur.com/TJhX4CM.jpg


Jacks/power top: https://i.imgur.com/LOsSsSb.jpg
bottom: https://i.imgur.com/ljS4dAo.jpg

Not actually sure how this is grounded at all - assuming on the power/jack pcb you're getting the ground from the power supply and then to the enclosure?

[stallik]

Pin 2 of your tone pot - soldering looks a little suspect. No solder has passed through the hole. Not sure if this is important but it's a double sided board and some components will need to be connected both sides.

Good luck and welcome to the forum. Really like the look of those resistors btw.

[ElectricDruid]

I think there's a problem around IC3 (often the case on Klon builds - the damn 1044 seems to cause 95% of the problems). Ironically, this doesn't really show up in the voltages around IC3, but on the power supply for IC2, marked "VB" on the schematic. It's supposed to be 18V (pin 8 of IC2), but you've got -7.21V. That's a long way wrong!
The -9V supply on pin 4 of IC2 looks ok, so some of the 1044 is working correctly.

Check the diode polarity for D3 and D4, and the two caps C20 and C21.

The voltages on IC3 don't look too bad in general, but there's a couple of pins that look a bit too low to me. The big problem is that 18V supply though - if you fix that, the chip might be happier and the other stuff might come right, so fix that VB supply first.

[idy]

One thing I wish was written in gold for every new builder: It probably is not the parts, unless you chose wrong values. Pulling things out to test them is how a lot of long frustrating threads begin. In the life of a pedal builder, about .01% of failures are bad parts....with exceptions (Ge transistors, rare ICs bought from shady dealers...)

Pulling things out to test them so terribly often means tearing one of those delicate copper traces off the board... then you have to confirm continuity, solder on a bit of wire or component lead...Not the end of the world, but a whole new world of unnecessary headaches. Many (most?) of us have never seen a "bad" resistor or capacitor fresh from the bag, or even a modern transistor (except FETs) ...but we have all torn traces.

One more silly thing easy to miss and impossible to say from your pics: you asked about grounding. Your set up will use little jumpers with molex connectors  and you are showing us the unassembled pieces of a pedal; power and jacks, footswitch, pcb. When all is together the sleeves of both jacks, the ground of the power jack, the ground of the pcb must all be connected. (Probably there is also a ground wire on the footswitch too for LED...but the original did something odd there...not crucial to iron that out yet.)

Jacks and PCB grounds all together somehow. Some foolish people use the enclosure touching the sleeve of the audio jacks instead of a wire. They are silly.

[duck_arse]

yes indeed, D3 and D4. they appear to be russian types, which mark the stripe on the Anode, whereas the board has the band marked for Kathode. if you peer thru the glass, you can see the disk of germanium, which is usually at the Kathode end of the diode. with those backwards, the charge pumps up negative volts, hence your -7 instead of +18. C20, 21, 22 will have been reverse voltsed, you might like to just pull those and throw them in the bin, will save you some headaches. pull the diodes and reverse them, they will be undamaged by the circuit - your de/soldering perhaps a different matter.

you are nearly there!

[ldornado]

Ok, this is starting to make sense... I think I put D1 and D2 where D3 and D4 should go. What capacitors would I want to replace if I got all four of those wrong? Now that I think about it, D1 and D2 were just the wrong diodes - they were not reverse volted, right?

edit: Shoot, looking for replacement C20-C22 and those parts are obsolete and Mouser is out of them. What can I use in place of 647-USR1H100MDD?

[idy]

Oh my. I think that means your two pairs of diodes are reversed: you have your germanium diodes serving the charge pump and your silicon 1n4001 as clippers.

Diode 1 and 2 (close to the side of the board) are clippers and should be those glass, Russian ones. In that application it wold not matter that A and K are flipped, because they are anti-parallel, one goes each way between two points.

Diode 3 and 4 (between the two ICs) serve the charge pump, carry current and should be those black 1n4001s, they can take power. There the polarity does matter and the stripes are the "right" way.

[idy]

The clippers reversed would not damage anything. They would work the same way.

[ElectricDruid]

edit: Shoot, looking for replacement C20-C22 and those parts are obsolete and Mouser is out of them. What can I use in place of 647-USR1H100MDD?

C20, C21, and C22 are 10uF electrolytic caps. There are millions of those in the world, and Mouser has lots. The only other important paremeter you need to worry about is the voltage rating. 35V would be a good minimum here, but you might well find 50V or 63V for the same price or less, in which case, go with those.

Here's a quick search on Mouser (Aluminium Electrolytic caps, radial leads, 10uF, 35V/50V/63V rated):

https://pt.mouser.com/c/passive-components/capacitors/aluminum-electrolytic-capacitors/aluminum-electrolytic-capacitors-radial-leaded/?capacitance=10%20uF&voltage%20rating%20dc=35%20VDC%7C~50%20VDC~~63%20VDC&rp=passive-components%2Fcapacitors%2Faluminum-electrolytic-capacitors%2Faluminum-electrolytic-capacitors-radial-leaded%7C~Voltage%20Rating%20DC

[Locrian99]

The forum store has 10uf 35v caps as well. 

[ldornado]

I had already purchased some of these (https://www.digikey.com/en/products/detail/rubycon/50ML10MEFC5X7/3562781) after their site claimed they were alternatives. CAP ALUM 10UF 20% 50V RADIAL. Please stop me before I put them in if they're going to do weird things 

[ElectricDruid]

Those look fine.

[ldornado]

An update...

I de-soldered all the diodes I messed up, put them in the right places, and soldered them back in.

I then replaced the caps I reverse volted, the resistors I pulled to test outside of a parallel circuit, and the tantalum cap. Put it all back together inside of the enclosure.

It sounds like a drive pedal - thanks for the help everyone!