EgoDriver Error

[metfreak]

So if I got that straight I have to charge PCB with 9V and start measuring? (Do I have to unsolder any of the components?)

Doing this thing first time so that's why I ask so much questions

Will provide measurments on IC within this weekend.

Nejc

[gtr2]

Yup, just power up with 9v and start measuring 

Josh

[metfreak]

The thing is I have an analog MM, so I think it would be better to have a digital one, right? So pins 4 is (around) 0V and pin 8 is around 9V? It's measurments I found in other topics.

[jkokura]

No, an analog is fine.

Yes, 0v at 4, 9ishv at 8. Approx 4.5v at the rest.

Jacob

[oldhousescott]

Analog is fine, just be sure you've got the selector set to the correct range (DCV) and make sure you're reading off the correct scale for your measurements. Also, make sure you're looking straight on at the meter face when you make the measurements.

[metfreak]

OK,I've measured the voltages and clearly is something wrong

They go like this:

1  |  1,5V  -  8  |  8,5V
2  |  1V     -  7   |  1,5V
3  |  1V     -  6   |  1,5V
4  |  0V     -  5   |  1,5V

Nejc

EDIT: Something I noticed while trying to solve this major problem I rewired gain and volume pots because I thought there was the problem, so when I plugged in it's working but still "farty" sound coming out of it and still one of the LEDs is shining while playing. What I figured is really strange, I kinda connected (with my fingers ) all 3 pots and one LED started shining bit more and sound was coming clearer, the other LED still no response...

Does that ring any bells?

[jkokura]

It looks like you've used incorrect parts or that you've got some connected poorly. It's really easy to mix parts up and install them in the wrong spots. I would do the following, even if you've already done it I would do it again:

Check you've used the correct part values.
Check you've used the correct part orientations.
Check you've used the correct wiring.

You could also have a part that's got a solder bridge, so check your soldering also.

Jacob

[metfreak]

So I resoldered all of the parts , the orientation only matters for electrolytic and tantalum caps, right? Checked again all the values for resistors and caps, resoldered and checked the wiring for pots and switches it worked for like 5 minutes and than again it when all buzzy...

[metfreak]

I've rewired whole thing... It's seemns to be working now, it still gets sometimes that buzzy sound but that because of the toggle switches which I guess melted somehow (they're some Taiwan cheap-ones). I still don't know where was the main problem maybe soldering or maybe even wires, all of them were replaced with "stronger" ones, or maybe after all the toggle switches...

[bigmufffuzzwizz]

Good job on getting it going! It sounds like something is making a bad connection to get that sound. Could be a bad solder joint like suggested or the switch could be melted and making bad contact inside like you said. Keep practicing you'll get better!

[metfreak]

Since I'm done with my EgoDriver and all the troubles I went through I've learned quite a lot. Also thanks goes to you guys being patient with my troubles trying to get this pedal done... Again thanks!

I've got another question concerning my problem. So is it possible that because of the bad wiring of gain and volume pots voltages on IC were not right?? Because I've measured them again and now they're like they suppose to be approx. 4.5; 0; 4.5 and 9V (mine Vs are 4.4; 0; 4.4 and 8.85V)??

Thanks again and have a great day!

Nejc

[jkokura]

8.85 pin 8 would be where you're starting from. That's your input voltage. If you use a battery that will slowly get lower, and if you use a power supply it could read 9 or 9.6 or whatever and will remain constant.

0V is ground, it's the opposite pole of your power source. Pin 4 should never read higher than that.

4.4V on the other 6 pins is to be expected because your starting with 8.85. This circuit, and many other overdrives, uses a combination of resistors and capacitors to divide the input voltage in half, meaning that you'd take your input voltage (8.85) and divide it in half (4.425, or 4.4 if you round) and that gets applied to the various parts of your op amp's gain stages.

Simply put, your voltages are perfectly fine, but would change if you changed your input voltage.

Jacob

[metfreak]

I've measured voltages with Boss adapter, so is that OK concearning the voltages?

One question that bothers me: Is it possible that because of the bad wiring of gain and volume pots voltages on IC were not right??

Nejc

[jkokura]

Simply put, your voltages are perfectly fine, but would change if you changed your input voltage.

Don't know about the 2nd question, but my guess would be that if it was a problem it would likely because something in the wiring was leaking your bias voltage to ground.

That 4.5V thing, where the voltage is divided, is usually called 'bias voltage'. Essentially, what it looked like was that the places where you should be seeing the 'bias voltage', around 4.5V, was somehow leaking some of it's power to ground, or to another area where it shouldn't. Maybe that was in the pots, but more likely it was on the PCB. A wrong part, a solder bridge, a cold joint - all of those could be the reason, and just as likely if not more likely than the pot wiring.

Jacob