Help with a Klon Clone Charge Pump question

[ShadSunsCrash]

(TL;DR) I built a Klon Clone with a charge pump that takes the 9 volts of power up to 18v. But of the three IC's i noticed one of them is measuring 22V, is this normal for an op amp to measure 22v in a pedal thats getting 18v from a charge pump? Pedal sounds excellent no hum or anything like that. I might just be paranoid cause of a mishap i had while building it which you can read about in detail below. Anyways any help would be greatly appreciated. Thanks
                                                                                                        -ShadSunsCrash


I just build my first pedal from beginning to end ( I've been modding my pedals for a few years and wiring my guitars for just about every option imaginable for about 10 years). Anyways heres my issue. The pedal is working great, sounds great. Assembly went perfect except for one part of the charge pump. I got distracted by my dogs barking cause they wanted me to let them outside. I didnt want to stop cause my iron had been on for awhile and i wanted to finish up installing the last few capacitors before i took a break. So i rushed to get the last few in and upon doing so realized i had put 2 4k7 caps where two 47k caps go. It shouldn't have been a problem cause i realized what i had done right away and went to swap them. Thats when i realized the slight bend i had put in the leads to hold them in place wasn't allowing be to get them out. I should mention the eyelets are very small. I tried using a desoldering pump, desolder wick, rosin, basically everything i new to do to get all to solder off so i could get the leads through. Well even though i was only applying heat a few seconds at a time I still lifted 2 eyelets from the back of the board and didn't do any favors for the other two. All said and done i was able to get the capacitors soldered to the top of the eyelets on the populated side of the board. And i plan on replacing the eyelets in the future etc. As i said everything is working but i went to test the op amps voltage and found that one of the three op amps is measuring 22v. Is this acceptable/ normal for a 9v pedal with a charge pump that should be bright the voltage to 18v? Im just worried the damaged eyelets might be doing something funny to the charge pumps output. If anything i thought it would be less. Anyways, thoughts?

[vigilante397]

Welcome to the forum

First question: have you measured the output of the charge pump to see if it's putting out the expected 18V? If the charge pump is putting out 18V but the op-amp is magically getting 22V then that would be very odd indeed.

Second question: Do you mean 4.7µF caps as opposed to 47µF caps? I'm assuming these are not 47kF capacitors!

Third question: Due to an agreement we aren't allowed to post Klon schematics on this forum, but can you post a picture of the board so we can see what you're talking about? A picture is worth a thousand words normally, but for debugging the value is a lot higher.

Fourth question: Is this a PCB build? If so I'm assuming it's double-sided? If so, you need to verify that the lifted pads in question didn't have any connections on the bottom side that are now missing.

[ShadSunsCrash]

Welcome to the forum

First question: have you measured the output of the charge pump to see if it's putting out the expected 18V? If the charge pump is putting out 18V but the op-amp is magically getting 22V then that would be very odd indeed.

Second question: Do you mean 4.7µF caps as opposed to 47µF caps? I'm assuming these are not 47kF capacitors!

Third question: Due to an agreement we aren't allowed to post Klon schematics on this forum, but can you post a picture of the board so we can see what you're talking about? A picture is worth a thousand words normally, but for debugging the value is a lot higher.

Fourth question: Is this a PCB build? If so I'm assuming it's double-sided? If so, you need to verify that the lifted pads in question didn't have any connections on the bottom side that are now missing.

Ok all great questions....

1. Im not sure where to measure the charge pump to get the total voltage. I measured them one at a time and from right to left the voltage rises to about 15 volts near the end.

2. Yes lol i should have specified correctly but they are 4.7 uf (4u7) and 47 uf (47u) so both are micro farads. Which my multi-meter wont read btw it only goes down to mf which drives me crazy.

3. Hope this works ... The four damaged eyelets are circled in one of the photos. When i checked them with my meter they were getting voltage, but im not sure if they are getting the right voltage. EDIT: The top two pictures are mine and the bottom 2 are just are pulled from online. I can take out the pcb from my pedal if it would help but I can tell you the eyelets on the bottom are gone or partially gone depending on which one we are talking about but its possible a connection is still being made.










4. Yes this was my concern as well it is a PCB build and there were traces where the eyelets were lifted but it SEEMS to be getting a connection still possibly through the barrel. Initially i put jumper wires to connect the traces i thought might be damaged and it worked but i removed them to see if it would work still and it did so i left them off. I dont remember there being a change in performance though ill have to try again to be sure. Is there a way i can reliably test continuity between the two through holes and their traces or will it possibly show continuity albeit from a different route?

EDIT: I just realized i was probably measuring the IC's wrong. The one on the right is reading 8.46V, the one in the middle is reading 23.06v, and the one on the left which is a different op amp than the other two is reading 16.4V. Now im measuring them by putting the COM lead on the ground lead of the op amp and the hot lead of my meter on the opposite lead from the ground lead diagonally. If this is incorrect then id be happy to know the correct way to read op amp voltage.

[idy]

Klon uses charge pump to generate -9 and +16 (or similar.)
If you measure the pins of that one Opamp you will see a difference of+-25. Maybe 22.  8+- and 14+- equals 22+-.

[vigilante397]

Klon uses charge pump to generate -9 and +16 (or similar.)
If you measure the pins of that one Opamp you will see a difference of+-25. Maybe 22.  8+- and 14+- equals 22+-.

+1 to this. Typically voltages are measured in relation to ground, but if you were measuring the op-amp voltage referencing the negative rail instead of ground then it is absolutely reasonable to expect 22V or more, as idy pointed out.

So if the pedal sounds excellent, then we can reasonably assume that the pads that lifted left the plated through-hole connection in tact, so everything that should be connected is connected, and the pedal is just fine

[ShadSunsCrash]

Thanks to both of you, that all makes perfect sense then for what im seeing. Lol and yes i did read it as negative voltage but assumed i had the leads turned around or something. Im still learning, at this point i can follow directions and i know all my components and have a basic understanding of what they do but im feverishly trying to understand how these circuits actually work. Anybody can follow directions you know? Anyways Ill have to chalk this one up to luck that the through hole barrel was still connected to the traces. It really does sound great( lol especially considering what little it cost me). Thanks again!!!