SOLVED El Sol - crazy noise!

muffinscruffin

New member
Hi all,

Like a lot of us I'm trying the El Sol for my first build. Like a LOT of us on the internet, I ran into a couple crazy noise issues, and I haven't really found them actually resolved anywhere on the internet. I'm also hoping to clean this up a lot because I'm hoping to build another for my friend's birthday next month!

I breadboard'd it, following the tutorial, and got crazy screeching noise out of my headphone amp, but the EL Sol sound nonetheless.
I figured it would work better on the PCB, so I tried soldering that up last night. Now I have the same exact symptoms...slow and weak signal, crazy feedback of noise and screeching.
I'm hoping when I put it in the aluminum enclosure it will fix the frequency interference but it seems like there are other issues at play here, and I don't want to start mounting if I still have soldering to do.

The issues:
-Sound doesn't come on immediately...seems like it has to "warm up" to start passing signal
-Huge noise floor when ON, with minimal guitar signal. I can hear the fuzz effect through the screen of noise at low levels
-Bypass seems weak and a little hissy too
-LED didn't come on
-When I plug a battery into my power jack (I have an adapter from my 1-spot power bank), I get reversed polarities at the jack??and can only get bypass signal
-The guitar's signal is so LOUD; by that I mean the sound of my single coils' background noise. There's obviously a ton of signal going through but not a lot of my sound.

I've tried:
-Changing power supplies: using a battery made it only pass sound in Bypass-maybe it's dead. Using my 1-spot grounded power supply helped the noise issue a lot, but didn't fix it
-Checking continuities from footswitch/board, and of grounds; I think I have it where I should, don't have it where I shouldn't. I do think this could be a problem area, those 3PDT switches are a doozy for a first-time solderer
-Different LM386N-4s, JRC386Ds; the Ds helped a little, now I'm using both, per recommendation I saw on this forum
-Cut LED off the board for now, ordered 3mms as opposed to 5mms? Seems like my 5 should have worked, Tayda didn't give me many options.
-Checking voltages/continuities of ICs...I'm getting 9.11V from pins 2->6 and ~8V from 3->6 (am I doing it right?)
-Ohming out the capacitors; Not really sure what I'm trying for here either, but 2 of my 10uf have wildly different values, and C3+C4 are showing no resistance at all. Is that normal for this circuit?

My 2 cents:
It's my first time soldering up a board and might have made some goofs. I don't see any burs or strands, but I also don't really have a fine tuned sense.
My Input and Output jacks seem to have some of my best solder work.
I can see I nicked a cap with my iron in one of the photos, that 10uf has the different value from the other.
I also hit the polyester film cap it looks like. I'm going to change the nicked 10uf. Should I change the film while I'm at it?

I'm also hoping I sourced the right parts. As a first-timer, I had a lot of questions and couldn't pull all my answers from Google.
I got almost everything from Tayda, the JRCs from Small Bear, and the LM386N-4s+sockets & silicon shielded/stranded 24awg from Amazon.

Are any of these components likely culprits for my noise problem? Does anyone have any fixes that haven't been shared yet?
 

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5mm led should have worked most likely had it backwards.
that 10uf el cap also looks a little burned.
maybe the 4n7 film too?

i would check continuity throughout the board, then once everything checks out check the voltages on your ic's
 
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5mm led should have worked most likely had it backwards.
that 10uf el cap also looks a little burned.
maybe the 4n7 film too?

i would check continuity throughout the board, then once everything checks out check the voltages on your ic's
I'll start with both of those. To check continuity through the board, you mean to make sure that the cap is connected to the IC through the board, etc?

Nic, I know it looks like it's bridged i the pic but there's no continuity there, I just poked it out of the way a little more. Switch is wired like the diagram but it is pretty sloppy.
NickC, are you saying I should put more solder on each joint, or resolder the whole thing? I do have another board too, but wanted to use that for the 2nd one!

Thanks for the eyes guys!
I think one of my problems is the old janky chisel tip on my iron. I couldn't be very accurate, especially on that footswitch. Also made me burnt those capacitors, I realized when I posted this.
 
to check for continuity use your DMM and put it in continuity mode, then touch your DMM leads to make sure you hear a beep (just letting you know it works), start with any joint and follow its trace to where it goes, touch the other lead to the joint and you should hear that beep. if not then reflow those joints repeat with all other joints until you have continuity throughout the board.
 
I'll start with both of those. To check continuity through the board, you mean to make sure that the cap is connected to the IC through the board, etc?

Nic, I know it looks like it's bridged i the pic but there's no continuity there, I just poked it out of the way a little more. Switch is wired like the diagram but it is pretty sloppy.
NickC, are you saying I should put more solder on each joint, or resolder the whole thing? I do have another board too, but wanted to use that for the 2nd one!

Thanks for the eyes guys!
I think one of my problems is the old janky chisel tip on my iron. I couldn't be very accurate, especially on that footswitch. Also made me burnt those capacitors, I realized when I posted this.
Looking again, I see what you did on the switch, that big loop of blue wire :) Funny, it's the kind of thing I would do myself!
 
to check for continuity use your DMM and put it in continuity mode, then touch your DMM leads to make sure you hear a beep (just letting you know it works), start with any joint and follow its trace to where it goes, touch the other lead to the joint and you should hear that beep. if not then reflow those joints repeat with all other joints until you have continuity throughout the board.
Awesome, thank you. LED turned out to be bad, I tried another one and it lit right up, tried the first one again both ways and it was a dud.
Everything checks out with continuities, and I have 9.11V + 8~ish on each, if I'm doing the right pins (Inputs + Vout). I can't seem to find if those are the right values, but I think the amps are good--I have the same problem when I plug in two 386D JRCs instead.
I replaced those burnt capacitors too, and I get a lot more guitar signal now!

It's still totally overwhelmed by the big buzz/hum that sounds kind of like a ground loop (even on humbuckers). It turns into a squealing kind of AM radio frequency when I hit the switch. It also changes in frequency if i budge the guitar's pot even just a little, and gets more hummy and less buzzy.
What's funny is if I touch the PCB or components, it quiets it all down.
I don't hear radio noise on the pedal, but it is...reminiscent of it. Is this the Oscillation problem I've been reading about here and there?

Or will this noise problem be magically fixed once I get it in the enclosure? That'd be sweet
 
when checking your voltages on your IC you need to set your DMM to read DC volts then touch ground to power ground and touch the positive to each pin at the joint of your Ic. write down what you find and post it
 
OK, got it thanks.

LM386:
1-1.3v.....8-1.3v
2-0v........7-4.6v
3-0v........6-9.1v
4-0v........5-4.4v

386D:
1-1.3v.....8-1.3v
2-0v........7-4.5v
3-.6v........6-9.1v
4-0v........5-3.9v

Do the values look good? There's some discrepancies in there but mostly on par with each other.
 
Hopefully that will fix it. If not, another thing to consider is that these switches can be damaged by heat pretty easily. Leaving the iron on a lug too long can break it beyond repair. Doing too many lugs in quick succession without a break to cool can also do it. If changing the jack wiring doesn't fix it completely then try continuity on the switch connections next (power off to the circuit). Use a low ohms range on your DMM, or continuity buzzer. You are looking for this:

1662881070933.png

I see that there are a few youtube videos on this exact testing procedure if you get lost
 
The best thing I ever did to help tighten up my work was invest in a decent soldering iron. I have a soldering station kind of iron, with digitally controlled temperature. It has made clean soldering a lot easier. I use it at 375 for pedals and 425 for amps. I don't know whether that celcius or fahrenheit but it's what works for me! Having the heat set right for your circumstances means less holding the iron to a switch to get it warm enough. With the right temp you simply touch the lug with the wire in place for a second, add some solder and it's done. No harm to anything.

A fine, clean and well tinned tip to your iron is essential. Wipe off any excess as you go. Don't let solder get dull and grey - it has to be shiny and clean.
 
I use a standard Weller 40 watt that comes with a coated Pointed tip.
When the coating wears off, I sand a new point on it like a Pencil & re tin it before each new PCB.
I just use a discarded moist sponge from dishwashing & wipe the tip clean every so often.
If the tip ain't Clean, it's gonna look Mean & nasty!
 
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