Friedman BE-OD Pedal

alltrax · Post by **alltrax** » 31 Jul 2017, 09:10

This is where I should have continuity, could it be a bad trace on the pcb ?
I'll desolder those 2 // 82k to better check the pads

bajaman · Post by **bajaman** » 31 Jul 2017, 10:14

bridge the pins with a wire and see if it works then

alltrax · Post by **alltrax** » 31 Jul 2017, 12:02

bajaman wrote:bridge the pins with a wire and see if it works then

That's what I did but still no sound, at all. I checked all the other connections around U1, they are ok, but who knows there may be other bad traces (if it's the case) here and there...

andlord · Post by **andlord** » 31 Jul 2017, 12:51

I have 3 of those boards and i checked all the connections before I started working on them. All 3 of them were fine. Are you sure you have no cold connections or shorts?

alltrax · Post by **alltrax** » 31 Jul 2017, 12:55

I'm pretty sure but will check again

Groovenut · Post by **Groovenut** » 31 Jul 2017, 14:46

What is pin 1 voltage after the wire jumper is installed?

bugg · Post by **bugg** » 31 Jul 2017, 15:29

alltrax wrote:they are ok, but who knows there may be other bad traces (if it's the case) here and there...

If the problem does turn out to be the PCB I will send you a replacement.

Although it's certainly not impossible, this would be the first defective PCB I have received out of several hundred boards. These boards are 100% e-tested for what that's worth... I don't doubt that a bad trace could slip through, but multiple bad traces are highly unlikely.

rmroza wrote:I also found out that yes, on all pots, the square in Pin1!...however and as I said before, some pots are working in the opposite direction!

The board was designed for 16mm PCB mounted pots. Yes, the square pin is lug #1 on ALL of the pots. It has been built, confirmed, and A/B'd by more than one person, including myself. If a control is working backwards you need to check your wiring.

Jan1966 · Post by **Jan1966** » 31 Jul 2017, 16:15

rmroza wrote: just noted this throughout the builds and on the Buggs board, some pots still are working in the opposite direction.

Hey mroza.
You connected all your pots with wires. Why? The pcb is designed for board mounted. You must have some of them them connected the wrong way round.

Jan1966 · Post by **Jan1966** » 31 Jul 2017, 17:36

Jan1966 wrote:
rmroza wrote: just noted this throughout the builds and on the Buggs board, some pots still are working in the opposite direction.
Hey rmroza
I might be wrong but on your video the middle connection on four of your pots looks not connected to anything. That is your resistance sweeper but I expect you know that anyway. Let us know if you need any help as you are very busy.

alltrax · Post by **alltrax** » 31 Jul 2017, 18:16

Groovenut wrote:What is pin 1 voltage after the wire jumper is installed?

With the wire jumper U1 pin 1 remains 8,6V and Pin 2 is Vref ie 4,6V
So, still a problem around U1 I guess

alltrax · Post by **alltrax** » 31 Jul 2017, 18:19

bugg wrote:
alltrax wrote:they are ok, but who knows there may be other bad traces (if it's the case) here and there...
If the problem does turn out to be the PCB I will send you a replacement.

Although it's certainly not impossible, this would be the first defective PCB I have received out of several hundred boards. These boards are 100% e-tested for what that's worth... I don't doubt that a bad trace could slip through, but multiple bad traces are highly unlikely.

Thanks Bugg

For the moment I prefer to continue to try to understand what's going on, not the sexiest part of building a pedal but where we learn the most

I'll let you know

bmxguitarsbmx · Post by **bmxguitarsbmx** » 31 Jul 2017, 18:52

alltrax wrote:
bajaman wrote:bridge the pins with a wire and see if it works then
That's what I did but still no sound, at all. I checked all the other connections around U1, they are ok, but who knows there may be other bad traces (if it's the case) here and there...

I worked as a CAD/CAM processor at a circuitboard manufacturer for 3.5 years and never saw a single board come back. Everything is possible, just unlikely.

Both inputs to an op-amp should always have the same voltage. If they don't, you have to figure out why. A solder bridge somkewhere is the likely culprit. Clean that flux off with alcohol to get a better view.

rmroza · Post by **rmroza** » 31 Jul 2017, 19:02

Ok, I went in and checked EVERY component for value and orientation (including the 10R resistor).

All components are correct in value and orientation! I then tried to box it up...no good.

"The board was designed for 16mm PCB mounted pots. Yes, the square pin is lug #1 on ALL of the pots. It has been built, confirmed, and A/B'd by more than one person, including myself. If a control is working backwards you need to check your wiring."

"Hey mroza.
You connected all your pots with wires. Why? The pcb is designed for board mounted. You must have some of them them connected the wrong way round."

Hmm. Something is a miss. All parts new. All parts correct in value and orientation. PCB, not vero or breadboard. I didn't/don't have PCB-type pots, so that's why chosen but irrelevant. Still should work the same and i don't use all 3 wires on some of the pots because some pins are connected, like 1 and 2 or 2 and 3. Doing it at the board or pot should be irrelevant also. The pots should be hooked up correctly knowing Pin 1 is the square and then 2 and 3 using industry standard pinout (with the pit shaft facing you and pins down, the pin on the left is #1 - http://sound.whsites.net/pots-f5.jpg

"I might be wrong but on your video the middle connection on four of your pots looks not connected to anything."

This is due as I said above, two pins connected at the board and shouldn't make a difference there or at the pot (usually ground also), so only carried one wire from the board and bridged both pins at the pot. On one of the other vero build or what not, I did run all wires...no difference.

Next Steps:
I will re-confirm pot pins and no bridges. After that, I'm at a loss without any significant troubleshooting and I currently don't have the time of it as in the middle of reverse-engineering a Merlin Metal amp also and need to get it back to the guy!

Any other suggestions?? Can anyone post clips of their verified build(s) and also A-B between diodes and transistors? Still haven't seen anything in regard to that.

Jan1966 · Post by **Jan1966** » 31 Jul 2017, 19:25

rmroza wrote:
I didn't/don't have PCB-type pots,

I knew you were going to say that. Have you heard of header pins to mount your pots onto the board if they are not right angle connectors. Do you know what header pins are?
Or even believe it or not, short lengths of wire will work.
You know your stuff.

bugg · Post by **bugg** » 31 Jul 2017, 19:26

That is correct that you can run two wires to the pots that are acting as a variable resistor (the ones with two lugs connected together), but it absolutely matters which two lugs you connect to.

If you connect to lugs 1 & 2 the resistance will increase when you turn the pot clockwise, connect to 2 & 3 and the resistance will decrease.

If one of your controls is functioning opposite to how it should then it is wired incorrectly.

For the sake of clarity I would highly recommend you connect all pots with THREE wires and not take any shortcuts in wiring... Consider performing any modifications AFTER your pedal is working properly using the standard components.

Jan1966 · Post by **Jan1966** » 31 Jul 2017, 19:52

rmroza wrote:Ok, I went in and checked EVERY component for value and orientation (including the 10R resistor).

All components are correct in value and orientation! I then tried to box it up...no good.

"The board was designed for 16mm PCB mounted pots. Yes, the square pin is lug #1 on ALL of the pots. It has been built, confirmed, and A/B'd by more than one person, including myself. If a control is working backwards you need to check your wiring."

"Hey mroza.
You connected all your pots with wires. Why? The pcb is designed for board mounted. You must have some of them them connected the wrong way round."

Hmm. Something is a miss. All parts new. All parts correct in value and orientation. PCB, not vero or breadboard. I didn't/don't have PCB-type pots, so that's why chosen but irrelevant. Still should work the same and i don't use all 3 wires on some of the pots because some pins are connected, like 1 and 2 or 2 and 3. Doing it at the board or pot should be irrelevant also. The pots should be hooked up correctly knowing Pin 1 is the square and then 2 and 3 using industry standard pinout (with the pit shaft facing you and pins down, the pin on the left is #1 - http://sound.whsites.net/pots-f5.jpg

"I might be wrong but on your video the middle connection on four of your pots looks not connected to anything."

This is due as I said above, two pins connected at the board and shouldn't make a difference there or at the pot (usually ground also), so only carried one wire from the board and bridged both pins at the pot. On one of the other vero build or what not, I did run all wires...no difference.

Next Steps:
I will re-confirm pot pins and no bridges. After that, I'm at a loss without any significant troubleshooting and I currently don't have the time of it as in the middle of reverse-engineering a Merlin Metal amp also and need to get it back to the guy!

Any other suggestions?? Can anyone post clips of their verified build(s) and also A-B between diodes and transistors? Still haven't seen anything in regard to that.

Connect everything properly. No shortcuts just do it.

alltrax · Post by **alltrax** » 31 Jul 2017, 20:37

bmxguitarsbmx wrote:
alltrax wrote:
bajaman wrote:bridge the pins with a wire and see if it works then
That's what I did but still no sound, at all. I checked all the other connections around U1, they are ok, but who knows there may be other bad traces (if it's the case) here and there...
I worked as a CAD/CAM processor at a circuitboard manufacturer for 3.5 years and never saw a single board come back. Everything is possible, just unlikely.

Both inputs to an op-amp should always have the same voltage. If they don't, you have to figure out why. A solder bridge somkewhere is the likely culprit. Clean that flux off with alcohol to get a better view.

I did it, then verified under a magnifying lamp, and rechecked by passing a thin blade between each solder. I am a 100% sure there is no solder bridge.
I also removed R5 to test directly the pad to U1 pin 2 : no connectivity.

bugg · Post by **bugg** » 31 Jul 2017, 22:03

alltrax wrote:I also removed R5 to test directly the pad to U1 pin 2 : no connectivity.

You're on to something there... There is a trace on the bottom of the board that runs from the junction of the 22K / 39K resistors (bottom end) to pin 2 of U1.

The top end of the 39K should connect to pin 1 of U1.

rmroza · Post by **rmroza** » 01 Aug 2017, 03:58

I liked the board over. Looks good. Not solder bridges n all component s correct.

I'm at a loss so spent 6 hours reversing that Merlin amp. I'm going to blow this thing out the door before going back to the pedal, but ok for shits n giggles I'll wire all 3 wires from the board to the pots n see if any difference. Again thou I did audit the traces on the board to the schematic, that is, the board would say show pins 1 and 2 connected, I would have a wire from either pin1 or pin 2 of the board and run it to the corresponding pot and bridge in that case pins 1 and 2 on the pot. Should be the same thing. Again, I will try all three wires as time permits n report back

alltrax · Post by **alltrax** » 01 Aug 2017, 07:42

bugg wrote:
alltrax wrote:I also removed R5 to test directly the pad to U1 pin 2 : no connectivity.
You're on to something there... There is a trace on the bottom of the board that runs from the junction of the 22K / 39K resistors (bottom end) to pin 2 of U1.

The top end of the 39K should connect to pin 1 of U1.

That trace between 22k/39k and U1 pin 2 is definitely wrong on my board (the one to pin 1 is OK though). But still no sound at all, even with the wire jumping the bad trace. I'm afraid I'll have to check all the connections on the board

Friedman BE-OD Pedal [traced]