Messages

I've biased my mn3207 to 5.2v on pin 3. Did you try to adjust trimpot?

I will try that again, but I have had it as high as 6.1V on the 4558, but I'll check it on pin 3 of the 3207
[/quote]
I swapped the clock and BBD for a known working 3101 and 3007 and changed the jumpers, all worked.
Put the jumpers pack and the BL 3207 and 3201 back in the sockets.
Adj. the trim pot to get above 4.0V on the pin 3 on the 3207 and viola, good audio!
Well I'll be hog-wallered.

I can move on to boxing it up now.
Thanks Sharpan and Scruffle

The voltages look okay to me.

I thought they were good as well.
I have probed at Q2 and have a clean signal going into 3207, and clean signal at pin 3 going in, just no good signal coming out.
Could the components after the BBD have an effect on the output to affect it in such a was as to reduce it to such a tiny audio signal?
Wrong resistor value?

I've biased my mn3207 to 5.2v on pin 3. Did you try to adjust trimpot?

I will try that again, but I have had it as high as 6.1V on the 4558, but I'll check it on pin 3 of the 3207

Pork Barrel build using BL3207 (MN3207 clone from Small Bear).
Have audio signal on pin 3 - very faint, highly distorted signal on pin 7 & 8.
Jumpers set for 3207 - vertical - Pin 1 test at 0V pin 5 test at 8.9V
Pin 7 & 8 test at just over 4V
What should pin 2, 4 & 6 test at?

BL3207
1 = 0V
2 = 4.35V
3 = 3.78V
4 = 8.25V <----?
5 = 8.91V
6 = 4.34V
7 = 4.54V
8 = 4.54V

Anyone with a working unit with MN3207 or BL3207 voltages that wouldn't mind posting them?

Thanks

To be fair, you were quite lucky, you beat 1 in 10 odds to put the only working chip in your first build! It's the little victories.

By the way... they'll probably send you more fake MN3007.

I would agree, may not be worth the postage to send them back! Put that money toward a known chip from Small Bear.

Well I assume you socketed the chips in the first pedal, why not just switch the chips round?

Yes, all IC's are socketed.
Well, I'm a cowardly lion. I was afraid of blowing the only working 3007 I had.

But... I did it anyway.
Results are:

1. From the signal probe you should hear signal from pin 7 & 8 on the BBD if the chip is working.
2. None of the 9 3007 I have worked in PB #1
3. 3007 #10 that works in PB #1 works in the PCB for PB #2 (confirming the new PCB is correct and functioning)
4. Contacted the seller on Ebay and they claim they will replace the 9 3007's. If so fine, if not lesson learned, spend the extra at Small Bear for a known working 3007 IC.

Thanks for your input

OK, so I'm building a second Pork Barrel by Mad Bean. 1st one is working well, so well I have an order build another for my Brother.

I got a lot of 3007/3101 ic's from seller on Ebay. One set is in my #1 PB Chorus and working well.
In my down time, I build an audio probe so I could be more efficient at resolving issue with my builds.

So I have the PCB populated except the 2 pots. I have inserted the pots without soldering to test the PCB. "Rock it before you box it"

I'm getting good voltages compared to the #1 PB pedal.
I'm getting sound from pin 3 of the BBD but nothing from pin 7 or 8 which is the output of the BBD.

I'm getting dry sound from the 4558 on pin 1 and 7 - the outputs - no chorus effect.

Should you hear the signal/sound on the BBD on pin 7 and 8?

Yea I have some eBay chips that I haven't tried yet. Really hit and miss.  Most of the U.S. computer/ electronic waste is sold to china and there is a large industry that strips the chips and re-surfaces them. I'm glad you got it working!

Thanks!
Thought I would post my first etch job on the enclosure the Pork Barrel is going in.

Did you check the resistor values? That is an easy mistake... I've made many times

Thanks for the reply, all replies are welcome!
I did that last night, pain staking as it was, with a resistor color code chart, schematic, parts list in hand.
checked all the Caps as well.
Found no errors - checked and re-flowed all solder points night before last.
Got the thing making a chorus effect now. Only took 3 MN3007 IC's before I got one that worked. 
Touched up all the soldering the night before and it still was not working. Didn't start working until I inserted the 3rd MN3007.

I got 10 sets of the 3007's and the 3101's from a seller in china on eBay. So if I can get 2 more sets out of the group that work, I'm ahead of the curve on price per set. HOWEVER, I still say $10.95 from Small Bear for a 3007 that is guarantied to work, is a lot less of a headache! and the way I would go in the future.

I need to re-check those voltages in the PB. I think I have a couple written down incorrectly. I would hold off before doing anything else (should be able to check in the morning).

Re-read the docs and saw that there was a note about the jumper pads.
I used sockets so I could change the jumper config without soldering. Just in case I could not find a 3007 that worked or was not counterfeit.
I have jumper horizontal across the sockets and I get voltage reading on the one closest to the 3007 so I'm guessing the sockets are not the problem.
Solder must have flowed or there would be no voltage at the top of R20 and pin 1 of the 3007.

I need to re-check those voltages in the PB. I think I have a couple written down incorrectly. I would hold off before doing anything else (should be able to check in the morning).

Me and my sanity will be standing by!   

Just completed a Pork Barrel and I'm not getting any chorus effect.
Voltages on both the 4558 and 072 look good but the 3007 and 3101 seem off.
Can anyone tell me where/what to look for?
3007
1. 8.9V  <--docs say should be 4.38
2. 4.38V
3. 5.4V
4. 8.13V  ---Not good docs say 0V
5. 0V       ---Not good - re-checked schematic and this is correct - ground
6. 4.27V
7. 8.67V
8. 8.67V

3101
1. 8.94
2. 4.27
3. 0
4. 4.28
5. Vari
6. 4.37  Docs say should be 0
7. Vari
8. 8.13

The values below are from the PDF doc for the Pork Barrel
IC1 4558        IC3 MN3007
1 6.2             1 4.94 - 4.99
2 6.2             2 4.95 - 4.99
3 6.19           3 4.31
4 0               4 0
5 6.2            5 0.62
6 6.2            6 5.45
7 6.2            7 4.65
8 9.19          8 9
IC2 MN3101      IC4 TL062
1 0.62              1 varies
2 2.4 - 2.7        2 4.54 - 4.59
3 7.3 - 7.8        3 varies
4 varies            4 0
5 4.65              5 4.54 - 4.58
6 0                   6 4.58 - 4.6
7 4.61              7 varies
8 9                   8 9.19

I have subbed a TL072 for the TL062 but I'm sure that is OK as the voltages look right.
I have adjusted the trim pot so my voltages look the same as the published voltages. (so I know the trim pot is working)
I have pulled the board from the enclosure and checked all the solder joints with a magnifying glass and no bridges.
I re-flowed any joint that remotely looked suspect.
Check the polarized caps and they are all correctly orientated and correct values.
I'm still lost.

Just completed a Pork Barrel and I'm not getting any chorus effect.
Voltages on both the 4558 and 072 look good but the 3007 and 3101 seem off.
Can anyone tell me where/what to look for?
3007
1. 8.9V
2. 4.38V
3. 5.4V
4. 8.13V  ---Not good docs say 0V
5. 0V       ---Not good
6. 4.27V
7. 8.67V
8. 8.67V

3101
1. 8.94
2. 4.27
3. 0
4. 4.28
5. Vari
6. 4.37  Docs say should be 0
7. Vari
8. 8.13