Building the Echo Base PCB

[Taylor]

That should be fine. I don't think it'll make any difference.

[Leftwing73]

Hey gang,

I just got two of these PCBs - great job Taylor.

Does anyone know of a good spot to wire in a dry effects loop on this board?

Thanks.

[MojoFilter]

so i put that missing resistor in my echo base and it was working great for a few days. i loved the sound and the extra footswitches were so much fun. then, i noticed that the modulation stopped working and the shortest delay time is way longer than before.
does anyone have an idea as to what may have happened?

[slacker]

Does the LED still flash when you turn the modulation on?
First thing I would do is check the connections to the modulation depth pot, if the connection to ground has broken that would cause the problem you're having. After that check the connections to PNP transistor.

[MojoFilter]

that was it! slacker saves the day once again
the wire going to the middle lug of the depth pot broke. i totally missed it every time i opened it up

thanks again!

[cyklopljud]

Hej everyone,
Just built up my Echo Base PCB and everything is functioning as it should except....
The bypass switch.
I have re flowed the solder and checked over the circuit.
Anyone else run into this?
Any ideas?

Thanks in advance.

O.

[jkokura]

Check your switch. Use a new one if you're not sure.

jacob

[Taylor]

Just to add some info that cyklopljud has told me via email, he has replaced the 4066, reflowed all the joints for the bypass wiring, he has wired the tails switch properly, and he's using BC549 instead of the 2n5089 for the switching transistor. He has verified that the transistor pins are in the right place.

I didn't think about swapping out the switch, good idea.

[cyklopljud]

Just to add some info that cyklopljud has told me via email, he has replaced the 4066, reflowed all the joints for the bypass wiring, he has wired the tails switch properly, and he's using BC549 instead of the 2n5089 for the switching transistor. He has verified that the transistor pins are in the right place.

I didn't think about swapping out the switch, good idea.

Check your switch. Use a new one if you're not sure.

jacob

thanks for the tip Jacob.
Strange I tried about 4 different switches, as well as just joining the wire together to make a short.
No luck, its very curious as I the rest of the circuit works. Well I have no way to know if the tails switch
is functioning until the bypass works, I guess.
Maybe the tails switch is the bad one.......?
I did read if the tails switch isn't connected there are issues, or did you say that Taylor?
So I will replace that after work.

hmmmm...

oh and thanks for the extra help Taylor.

O.

[Taylor]

Yeah, I don't remember who or what forum but somebody didn't want the tails function so they left this unpopulated and the bypass did not work right. You can just take the wiring out and jumper the center pad to one side to take that switch/wiring out of the equation.

[cyklopljud]

Yeah, I don't remember who or what forum but somebody didn't want the tails function so they left this unpopulated and the bypass did not work right. You can just take the wiring out and jumper the center pad to one side to take that switch/wiring out of the equation.

I will let you know how it goes.
It sounds fantastic, the fact I can modulate the LFO makes it all the better.

O.

[cyklopljud]

I had no luck changing out the tails toggle switch, still no bypass.

I will go over the circuit again and re-flow everything, I probably missed something.

O.

[slacker]

What does the LED do? Knowing that would help.

If you've got a meter that should be able to tell you where the problem is. If you measure the voltage on the collector of the bypass transistor, that's the pin nearest the CD4066, with the bypass switch open or disconnected you should get about 1 volt or lower. With the switch closed or the wire shorted to ground you should get 8 volts or more. If you don't get similar readings then the problem is somewhere around the transistor.
If the voltages are Ok, then measure from the middle pin of the tails switch, you should get the same readings as at the collector. Then measure from pins 12 and 13 of the CD4066, depending on the position of the tails switch one of those should follow the collector and the other should be about 9 volts.

Let us know what you find and we can go from there.

Yeah, I don't remember who or what forum but somebody didn't want the tails function so they left this unpopulated and the bypass did not work right.

Yeah that's right if you leave out the tails switch the pedal is hardwired on and the bypass won't work. The tails switch routes the signal from the bypass transistor to either of the CD4066 gates to cut the input or the output of the PT2399, so without the switch or a jumper the signal doesn't get to the CD4066.

[cyklopljud]

What does the LED do? Knowing that would help.

If you've got a meter that should be able to tell you where the problem is. If you measure the voltage on the collector of the bypass transistor, that's the pin nearest the CD4066, with the bypass switch open or disconnected you should get about 1 volt or lower. With the switch closed or the wire shorted to ground you should get 8 volts or more. If you don't get similar readings then the problem is somewhere around the transistor.
If the voltages are Ok, then measure from the middle pin of the tails switch, you should get the same readings as at the collector. Then measure from pins 12 and 13 of the CD4066, depending on the position of the tails switch one of those should follow the collector and the other should be about 9 volts.

Let us know what you find and we can go from there.

Yeah, I don't remember who or what forum but somebody didn't want the tails function so they left this unpopulated and the bypass did not work right.

Yeah that's right if you leave out the tails switch the pedal is hardwired on and the bypass won't work. The tails switch routes the signal from the bypass transistor to either of the CD4066 gates to cut the input or the output of the PT2399, so without the switch or a jumper the signal doesn't get to the CD4066.

@Slacker, the LED lights up no problems and responds to the LFO speed (If LFO modulation is switched in).
I will check what you suggested, I think your right something is fishy around the transistor.

Thanks.

[slacker]

Does the LED go on and off with the bypass switch?

[cyklopljud]

Does the LED go on and off with the bypass switch?

Woops sorry, left out the most crucial of info.
No it doesn't respond to the bypass, just stays on.
There is no response in the circuit to the bypass.
(I am using BC549 instead of the 2n5089)

Thanks.
O.

[slacker]

Check the transistor is the correct way round, sounds like you've already done that. The BC transistors I've got have the opposite pinout to a 2N5089, so the rounded side would be facing the edge of the board.
If you can let us have the voltages on all pins of the transistor that would help.

[cyklopljud]

Check the transistor is the correct way round, sounds like you've already done that. The BC transistors I've got have the opposite pinout to a 2N5089, so the rounded side would be facing the edge of the board.
If you can let us have the voltages on all pins of the transistor that would help.

I have socket-ed the transistors and checked the data sheets for the pin outs, but now I am guessing I have a cold solder joint on it.
(I am not near the circuit right now.).

[cyklopljud]

Check the transistor is the correct way round, sounds like you've already done that. The BC transistors I've got have the opposite pinout to a 2N5089, so the rounded side would be facing the edge of the board.
If you can let us have the voltages on all pins of the transistor that would help.

I found I had over heated my BC549, replaced it then...
Bam it worked.

Thanks for the help guys.

O.

[Taylor]

Cool, glad you got it working.