PROBLEM ECHO BASE DELAY HELP PLEASE

[hanibal1616]

SORRY, SOMEONE TO HELP ME, I just built this circuit, but the sound is passing by, without any change, I previously built a similar pedal, and it worked without problems, I already checked all the tracks and everything is correct, I no longer nothing else happens.

[Big Monk]

SORRY, SOMEONE TO HELP ME, I just built this circuit, but the sound is passing by, without any change, I previously built a similar pedal, and it worked without problems, I already checked all the tracks and everything is correct, I no longer nothing else happens.

I would begin by telling us:

1.) What circuit
2.) Post a schematic
3.) Post any important voltage values
4.) Show us the underside of the board

[hanibal1616]

SORRY, SOMEONE TO HELP ME, I just built this circuit, but the sound is passing by, without any change, I previously built a similar pedal, and it worked without problems, I already checked all the tracks and everything is correct, I no longer nothing else happens.

I would begin by telling us:

1.) What circuit
2.) Post a schematic
3.) Post any important voltage values
4.) Show us the underside of the board

Este es el esquemático

4066

1 4.63
2 4.63
3 0.3
4 0.3
5 0
6 4.3
7 0
8 2.9
9 2.8
10 4.64
11 4.65
12 8.86
13 9.5
14 9.27

pt2399

1 4.98
2 2.487
3 0
4 0
5 oscillates
6 2.4
7 4.58
8 4.56
9 2.49
10 2.49
11 4.27
12 0.13
13 0.98
14 4.94
15 2.48
16 2.48

i/o tl072
1 5
2 5
3 5
4 0
6 5
7 5
8 9.24

mod tl072
1 oscillates 4-6
2 5
3 oscillates 0.7-0.8
4 oscillates 0.7-0.8
5 oscillates 4-6
6 5
7 oscillates 0-2
8 8.48 oscillates



Thank you very much for the quick reply, sorry for my bad English

[ElectricDruid]

Bienvenido Hanibal!

Pins 12 and 13 on the PT2399 look suspicious to me. Check the connections on the components there. I'd expect something closer to 2.5V.

Does the 4066 switching work correctly? Does the LED turn on/go off like it is supposed to?

Is the level pot wired correctly? If it was wrong, you might have it turned down to zero when you thought it was turned up to maximum.

[antonis]

It should worth a solder joint check there:



P.S.
Any chance for BC550 to be placed flipped 180^o..??

[anotherjim]

Is there a layout error in that pcb design? PT2399 pin11 should only go to a 100n cap - it looks like it connects to parts only pin12 should connect to.

[iainpunk]

pins 11 and 10 look like they are not connected at all... to anything!!!
maybe that?

welcome to the forum,
cheers, Iain

[anotherjim]

Think I was reading the PT pins wrong direction - pin 11 is top right and looks like it only has one connection.

[Mark Hammer]

There looks to be about a half a pound of solder on there!  Did you used to work for Electro-Harmonix in the late 1960s? 

Seriously, this is not a scolding, but I think you will find it easier in future to make all solder joints a little more "modest".  I think it is good practice to tin all the PCB traces and pads, before installing parts - at least that's what I do - but a little bit of solder goes a long way when doing that.  When preparing my own boards after etching, I buff them down with fine steel wool or a Scotchbrite pad, and then wipe some liquid flux over the board, before it has a chance to tarnish.  The flux allows a tiny bit of solder to cover/tin a LOT of copper.  Then, once I have tinned the board, I clean off all that flux with methyl hydrate (though there are other solvents one can use), such that I have a nice clean shiny board.  THEN I drill the holes.

Finally, I often find that, on "busier" PCBs (lots of solder joints with many close traces and pads), it can help with troubleshooting to clean off the flux after installing all the parts and wires.  It is not a requirement.  I just find that dried flux can be so shiny that it makes it harder to see any solder bridges between traces or pads underneath the flux.

[hanibal1616]

I have checked continuity on all tracks.
I even reverse printed the channels to check the tracks

will that be enough?
legs 10 and 11 are exactly connected as the diagram says
Thank you all for your advice, I will review everything that you indicated and will report immediately how it went.

[hanibal1616]

Bienvenido Hanibal!

Pins 12 and 13 on the PT2399 look suspicious to me. Check the connections on the components there. I'd expect something closer to 2.5V.

Does the 4066 switching work correctly? Does the LED turn on/go off like it is supposed to?

Is the level pot wired correctly? If it was wrong, you might have it turned down to zero when you thought it was turned up to maximum.

Of course, the led turns on and off, I have not had problems with the 4066 even I tried it only with jumpers and nothing.
I have more than one pt2399 and 4066

[antonis]

Any chance for PT2399 leg(s) bent underneath chip body..??

[ElectricDruid]

I have checked continuity on all tracks.
I even reverse printed the channels to check the tracks

will that be enough?

That's great, but it'd help even more if it was the right way up! Don't worry, I've worked it out now, but it had me confused at first.

[Marcos - Munky]

What about a link to the layout. Is it verified?

[anotherjim]

The problem with heavy soldering if that there may be a lump over a component leg, but that don't mean it's actually connecting. You need to see some of the leg. It's worse with polybox capacitors because you can't get a meter probe tip on the leg to prove it has connection to the pcb track.