Gravitation reverb

[steviejr92]

Hi guys I’m new to pedal building and this is my 3rd build the gravitation reverb. I had populated the board and I wired it to jacks and stomp switch I had bypass when it’s turned off but when engaged I get no sound even though the led light turns on. Which leads me to believe the problem is on the circuit board yet I have looked at others boards and mine doesn’t look any different I don’t if my parts are low quality if that a thing but all of my polarities on my electrolytic capacitors are right both my ic chips are on correctly, I do use bojack resistors from a kit but I don’t know if that will affect anything I did notice the legs are a bit thinner but others other than that they’re all the right values. I checked my pots and they’re on correctly and I do have the right belton reverb chip soldered directly the only the thing different I could notice was the voltage regulator the pub calls for L78L05 but I have LM78L05ACZ I don’t know if that’s it I read somewhere that the pin out might be different but I’ve gotten 2 different answers yes and no lol. I’m lead to believe this is the problem. Can anyone help me out here I’ve ordered a 2nd board and reverb chip since I feel like the parts could be duds……oh and I forgot to mention because of that confusion about the voltage regulator I’ve removed and tried backwards and the same thing and now I e ruined the eyelets where it’s needs to go idk if it’s salvageable but I’ll be posting pics please help lol

 

[Chuck D. Bones]

You have to be pretty brutal to destroy the pads on one of these boards.

 

[steviejr92]

yeah the constant reheating melted my eyelets again I’m very much a beginner lol

 

[Chuck D. Bones]

Consider this a practice run and do better next time. What kind of soldering iron are you using?

Also, don't replace parts unless you know they are bad or installed wrong. Do visual inspection to find the wrong part, bad solder joint, etc.

 

[steviejr92]

Im using a simple soldering that plugs directly into the wall it’s not a station and I use a fine tip to solder

 

[Chuck D. Bones]

You need a temp controlled solder station to do this right. Those cheap soldering irons get too hot and will damage boards and parts. Keep using that iron and you're going to spend a lot of time & money fixing botched boards.
Let me be candid: You need the right skills and tools to build pedals. Skills take time to develop and tools cost money. Many of us got into this thinking we were going to save money by building our own pedals. You might save a little $$$, but this is a labor of love and requires an investment of time and money if you're going to be successful.

 

[steviejr92]

So I’ve listened to your advise and bought a new multimeter and solder station! The station is on its way but in the meantime I have been checking continuity throughout the board and there are definitely a couple of resistor, electrolytic caps and a couple pots not getting any power at the very least very little to the point the meter won’t beep. I’m not sure where I should go from here should I start trying to resolver all the joints?

 

[Chuck D. Bones]

I think that board has seen enough heat already. Can you provide some specific examples of where you are measuring continuity and not getting the expected result?

 

[steviejr92]

I’m measuring from the power jack and touching all the components leads let me provide pics

 

[Chuck D. Bones]

No, no, no. You will not get continuity from the power jack to every component. Electronics does not work that way.

Do you know how to read a schematic?

 

[steviejr92]

I do not sir I’m very much a beginner at this where should I start in terms of where to place the meter?

 

[steviejr92]

So this is the schematic here I’m not sure where I should start I circled ic3 because it seems to be connecting to everything else in the board but I’m not sure where that would be on the actually circuit board. Sorry guys if I’m not being super clear or if my inexperience bothers you guys just trying to fix my board if it’s fixable lol

 

[Chuck D. Bones]

Where to place the meter is different for every circuit and troubleshooting situation. By way of an example, you could check the bias on the opamps on your Gravitation board. To do this, set the meter to measure DC volts. Connect the DMM black (negative) lead to ground at the IN, OUT or POWER jack. Apply power. Touch the red (positive) lead to pin 1 or pin 7 on each of the TL072s (one at a time). you should get about 4.5V.

We are not an accredited school, but we do provide a fair amount of instruction on basic electronics, pedal design, building and troubleshooting. Peruse the forums and you'll find a wealth of information.

Here's a good starting point: https://forum.pedalpcb.com/forums/the-test-kitchen.32/

 

[Chuck D. Bones]

So this is the schematic here I’m not sure where I should start I circled ic3 because it seems to be connecting to everything else in the board but I’m not sure where that would be on the actually circuit board. Sorry guys if I’m not being super clear or if my inexperience bothers you guys just trying to fix my board if it’s fixable lol

We all have readable copies of the schematics, no need to post photos of the build docs.

Read some of the other troubleshooting threads to get a flavor of how troubleshooting is done. We help plenty of guys who are new to this and/or have little or no electronics background. We can walk you thru the steps. Visual inspection is your #1 troubleshooting tool. Get used to doing that and you're more than half-way home.

 

[steviejr92]

Thank you so much for this this is going to be a big help this is a passion I just recently found and I’m sticking with it you’ve been a big help but to continue this I’m only getting .30 volts when I’m making contact with pin 1 and nothing else on either pins I did this with both opamps

 

[Chuck D. Bones]

I'm going off the air for the rest of the day, maybe someone else can jump in and assist you.

 

[steviejr92]

No problem sir thank you so much I will continue to use the forum and read up more info about how to troubleshoot thank you for your time again!

 

[mybud]

I do not sir I’m very much a beginner at this where should I start in terms of where to place the meter?

Reading schematics is a good skill to develop, alongside the visual inspection @Chuck D. Bones recommends. Try to do this inspection from the start, so that you spot any soldering errors from the get-go. It helps to take it slow at the start (say, do five or so components at a time and then check that these are all ok), and take breaks to help your concentration recover.

Adafruit has a basic soldering guide to help distinguish between joints that will work and dry or cold joints, which often appear dull. You’ll begin to get how basic circuits work soon enough, given that usually they are built out of smaller blocks (input stage, filters, and so on) combined in more or less regular fashion. Take it slow and enjoy what you are about to create. Maybe practise building some simple circuits to start.

The troubleshooting threads are well worth checking out, as the man said. There’s a wealth of good info there. When you learn to combine passion and precision, you’ll reap the rewards of a highly addictive and seriously fun hobby.

 

[Robert]

Lets start by making sure you're getting good readings with your DMM.

Set your meter to measure DC volts then power up the circuit and measure the voltage on the DC jack.

Black lead on negative terminal, Red lead on positive terminal.

 

[steviejr92]

So I just got 8.92 volts on the DMM

 

[steviejr92]

Reading schematics is a good skill to develop, alongside the visual inspection @Chuck D. Bones recommends. Try to do this inspection from the start, so that you spot any soldering errors from the get-go. It helps to take it slow at the start (say, do five or so components at a time and then check that these are all ok), and take breaks to help your concentration recover.

Adafruit has a basic soldering guide to help distinguish between joints that will work and dry or cold joints, which often appear dull. You’ll begin to get how basic circuits work soon enough, given that usually they are built out of smaller blocks (input stage, filters, and so on) combined in more or less regular fashion. Take it slow and enjoy what you are about to create. Maybe practise building some simple circuits to start.

The troubleshooting threads are well worth checking out, as the man said. There’s a wealth of good info there. When you learn to combine passion and precision, you’ll reap the rewards of a highly addictive and seriously fun hobby.

Thank you so much for the support! This is a fascinating hobby and to be honest I’ve never soldered or even took a class on electronics lol everything up to this point I’ve learned by myself and I continue to absorb so any advise and guidance is very much appreciated!