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

 

[Robert]

It looked different in the pic above, but it was small so hard to say for sure.


OK, black lead on ground, then measure the voltage on both ends of the 1N5817 diode right there.

 

[steviejr92]

So now on the dc jack it reads 8.92 volts but negative

 

[Robert]

What power supply are you using?

 

[steviejr92]

8.94 volts on the diode

 

[Robert]

On both ends of the diode?

 

[steviejr92]

Scratch the negative thing I was confused lol

 

[steviejr92]

Yes on both ends of the diodes

 

[Robert]

Disconnect power from the pedal.

Switch your meter to continuity mode (beep test). Touch the leads together to make sure it beeps.

Now check for continuity from the Right end of the diode (Stripe) to Pin 8 of either opamp.

 

[steviejr92]

I get no continuity on pin 8 of either opamp from striped side of diode

 

[Robert]

OK that's going to be the problem. Make sure you have continuity between pin 8 of both opamps.

(Pin 8 of IC1 to Pin 8 of IC2)

 

[steviejr92]

In other words should I resolder? Problem being there’s a big reverb module in my way lol

 

[steviejr92]

I did buy another board from you guys should I rebuild I also bought a solder station so this time hopefully the joint will be made much better btw any advise on temp when soldering?

 

[mybud]

'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'

Is this perhaps the culprit? Sorry, lurking with keen interest.

 

[steviejr92]

I’ve been told by the admin that I should still be getting some kind of clean tone even with out the regulator there

 

[Robert]

If you have some insulated wire we can probably fix it, but we need to determine where the trace is damaged for sure first.

The measurement between pin 8 of the two opamps will help determine that.

I suspect @mybud is correct, it's broken at the regulator pad.

 

[Robert]

However, since you do have a new PCB coming, if you'd rather wait and rebuild you can do that as well.

 

[steviejr92]

in your opinion should I just rebuild is there anything I can hervest from this oxbow or should I use all new parts? I also bought another module I have pretty much everything else to build another. I also have one more question the parts I used I’ve bought the caps pots diodes and hardware from stomp box parts and the resistors are from a kit I guess my question is are my parts quality at least for this build to work?

 

[steviejr92]

*pcb

 

[Robert]

If you have the parts it would probably be easier to rebuild with new rather than trying to salvage.

I'd save the opamps if they're socketed.

You can absolutely salvage the other components, but I would personally toss it into a box for later so you can start fresh and not add any new problems into the mix.

The components from StompBoxParts will be good quality, no problems there.

I can't comment on the resistors but as long as the value are correct you shouldn't have any problems.

 

[steviejr92]

I have 24 Gauge wire will that do?