Madbean Porkbarrel 2019 Need Help!

[mickeybellinello]

Hi to all!

This is my first post, I'm Mickey and I'm from Italy.
Recently I built a Porkbarrel 2019 (it's a CE2 Clone) but it doesn't work properly.
I mean, the dry signal (using the blend knob) is right but there is no wet signal at all. I double checked all the soldering points and it seems all ok. I audio probed the MN3007 (due to madbean suggestion) and I noticed that at pin 3 (mn3007 input) there is signal but I have no signal at pin 7and8 (mn3007 outputs).
I checked all the voltage and the most significant things is that I have 0.6 measurement instead of 4.7 reference at pin 7 and 8 of the mn3007.
The other measurement are the following:
IC 1:
Pin 1:4.33
Pin 2:4.34
Pin 3:4.33
Pin 4:0
Pin 5:4.33
Pin 6:4.34
Pin 7:4.33
Pin 8:9.10

IC 2:
Pin 1:8.10
Pin 2:4.16
Pin 3:3.50
Pin 4:0.793
Pin 5:0
Pin 6:3.83
Pin 7:0.610
Pin 8:0.610

IC 3:
Pin 1:8.12
Pin 2:3.83
Pin 3:0
Pin 4:4.16
Pin 5: varies
Pin 6: varies
Pin 7: varies
Pin 8:0.796

IC 4:
Pin 1:varies
Pin 2:4.55
Pin 3:varies
Pin 4:0
Pin 5:4.53
Pin 6:4.60
Pin 7:varies
Pin 8:9.10

Q1:
E:3.53
B:3.86
C:9.10

Q2:
E:3.68
B:4.18
C:9.10

Q3:
E:3.59
B:3.96
C:9.10

Q4:
E:varies
B:varies
C:8.12

Q5:
E:0
B:varies
C:varies




Can someone have ideas or can help me please?

Thanks So!

[thomasha]

Hi,

are you using the MN3007 or a newer version like BL3207, V3207? Which jumpers did you used?

I had some bad luck with MN3007s, that were either dead or a fake and also had lower voltages at pin 7 and 8 and there was no way of getting it right.
Someone had a similar problem where the chip was inverted, but that would be almost impossible to identify without frying it.

Where did you get yor MN3007 from? Do you have a known good MN3007 IC from another pedal that you could test?

So, looking at your voltages, the BBD should be IC2 right?

Your pin 1 is lower than the 9.10v in the other chips.

Pin 3 is also a little lower than I would expect. It should be closer to 4.9v, so that the BBD is correctly biased, otherwise there will be no signal at the output.

I would check the jumpers to see if they are connected in the correct way for your BBD.
Then look for something that could be affecting pin 1, where I would like to see 9v and pin 3 where it should be higher than 4.5v.

[ElectricDruid]

From the photo above, it's an MN3007/MN3101 and the jumpers look right. Docs are here:

http://www.madbeanpedals.com/projects/_folders/FilterMod/pdf/PorkBarrel2019.pdf

I think I'd probably be looking to see if there's a good solid clock signal. After all, if the output is too low, that suggests that no signal (with it's associated bias level) is getting fed through.

Do you have a multimeter that can measure frequency? Or (better still) an oscilloscope? Or a friend with an oscilloscope?! I'd check those clock outputs, but before that, I'd check the soldering around the clock chip carefully and see if you can't get it to spring to life.

[mickeybellinello]

Thanks to all for the support.

The BBD is an MN3007 and the jumpers are soldered in right way according to madbean sheet.

Unfortunately at this moment I've no other mn3007 but I just ordered a new one from a supplier that told me he will test the chip before the expedition.

I made some other check and all seems to be ok (I tried several mn3101 and the situation is always the same), so at the moment I'm waiting for the new mn3007 and I'll update you.

Thanks again!

[antonis]

Do pots have some kind of "isolation" ..??
(not just "enough" space from PCB..)

[mickeybellinello]

Here I am!

I solved the problem! I received this morning a brand new mn3007 and now all works well!
Probably a fake or a defective unit again!

Thanks for the support! Really!