Pork Barrel No Chorus

[mjcyates]

Just finished a Pork Barrel and I am getting no effect. Signal passes in bypass mode and when engaged. Just no chorus. Can someone post the correct voltage readings? I know the MN3007 and MN3101 chips are fine because they work in my older Pork Barrel. Thanks.

[mjcyates]

Anyone?

[Bret608]

What kind of readings are you getting? I'll bet if you post yours, if Scruffie sees it he'll be able to spot right away if something is amiss.

I would check my voltages and post for you, but I used the v3207 and I'm afraid I'll be leading you astray if that has any differences with the MN3007.

[nzCdog]

I don't have a pork barrel anymore, so can't give you any readings :/

If you're using the current board, check you've jumpered under IC4 correctly.  Best bet is to scan the board for bad or missing joints, then follow the schematic with a voltmeter looking for weird voltages... failing that audio probe to see where the chain is broken.
If you're getting the only signal when engaged, then you can prolly start checking from c8 onwards in the schematic.  Good luck

[mjcyates]

I opened up my working Pork Barrel from the previous layout and took voltage readings on the IC's. Below are the readings from my working pedal on the left and non-working pedal on the right. The only ones that look to have a significant difference are Pin 1 of the MN3007 and Pin 6 of the MN3101. Anybody see anything that could be an issue?

Working Unit      Non-Working Unit
      
JRC4558      JRC4558
1 – 7.0     8 – 9.5      1 – 6.5     8 – 9.5
2 – 0.8     7 – 7.0      2 – 0.3     7 – 6.5
3 – 0.7     6 – 1.8      3 – 0.6     6 – 0.4
4 – 0.0     5 – 2.0      4 – 0.0     5 – 1.5
      
TL062      TL062
1 – 4.5     8 – 9.5      1 – 4.5     8 – 9.5
2 – 1.0     7 – 4.5      2 – 1.0     7 – 4.5
3 – 0.4     6 – 0.0      3 – 0.4     6 – 0.0
4 – 0.0     5 – 1.0      4 – 0.0     5 – 1.0
      
MN3101      MN3101
1 – 9.0     8 – 0.4      1 – 9.0     8 – 0.3
2 – 4.5     7 – 0.5      2 – 4.5     7 – 0.5
3 – 0.0     6 – 4.5      3 – 0.0     6 – 3.5
4 – 4.5     5 – 0.2      4 – 4.5     5 – 0.4
      
MN3007      MN3007
1 – 9.0     8 – 0.2      1 – 7.8     8 – 0.2
2 – 4.5     7 – 0.2      2 – 4.6     7 – 0.2
3 – 1.5     6 – 4.5      3 – 1.3     6 – 4.6
4 – 0.4     5 – 0.0      4 – 0.3     5 – 0.0

[mgwhit]

Your voltages look wildly off for both your working and non-working pedals.  Take your 4558 for example: that should have approximately the value of your VB on pins 1-3 and 5-7.  Not sure what to tell you if you actually have one working with the values you posted, but my own has about 4.56V on 1-3 and 5-7 (as do at least three other Pork Barrels I've found searching the Tech Help forum).  Can you test your VB value on pin 2 of your trimmer (or the positive lead of C23 or some other point with an unobstructed feed from VB)?

I'll look at the other voltages and see what I can suss out later tonight.

[mjcyates]

Thanks for your response, I will double check my readings as well as checking pin 2 on the trimmer and C23.