Yeah, it's not terribly difficult. It's rather apparent when you've dialed it in.
Biasing the Pork Barrel is very straight forward. Set your Rate knob to its midpoint and the Depth knob to maximum. Ad- just the T1 trimmer until you get the maximum chorus effect with minimal distortion. That’s it!"
To bias the chorus effect, set the VB trimmer to its midpoint. Now adjust it left and right while playing
your guitar until you get the chorus effect. You most likely will not need to make a fine adjustment.
There is a wide range the chorus will work over.
LPG ADJUST (i.e., GATE TRIM)
The recovery filter’s lowest frequency can be adjusted, to fine tune the way it will react to incoming signals. Lowering this frequency emphasizes the action of the low pass filter, effectively raising the threshold of sensitivity. Adjustment should be made with the following settings: MIX full wet, LPG minimum, DEPTH minimum. While listening to a signal going through the pedal, you’ll hear the effect of the recovery filter at its resting state. Carefully turn the trimpot labelled LPG adjust (i.e., GATE TRIM), clockwise to raise the filter’s frequency, counter-clockwise to lower. Be very careful, adjustments should be minimal as the trimpot is very sensitive. After each adjustment, LPG should be turned up momentarily to listen at the envelope’s response to the incoming signal.
I set the BBD/BIAS trim pot similar to the pot on a CE-2 or Caesar. Adjust for the least amount of distortion with chorusing.
The GATE trim pot is user preference, it controls the frequency of the low pass filter portion of the gat
Hey did you ever sort this out? I have the same symptoms as you, effect when moving the depth back and forth but as soon as I stop it’s normal signal, lpg knob doesn’t seem to affect anything despite playing around with the trimIve been trying to dial in the low tide setup most of the afternoon. But im not getting any chorusing. I do notice a chorus effect when moving the depth pot back and forward but once its stopped moving i dont hear any chorus effect. My gate trim pot is low passing the audio and if i set it to low (CCW) it kills the audio. The BBD trimmer seems to have a sweet spot at 90% CW. But im not hearing any chorusing.
this comment leads to to suspect something isn't right:
I've gather all the comments relating to biasing the low tide:
I'll post some voltages tomorrow, is there a way i should set the knobs before i read voltages?
Cheers
Having the same issue here as well! No chorus effect, but Gate seems to work, and chorus is only audible while turning the Depth knob.Any luck? Having literally the same issue here, no modulation effect at all. Gate is working fine, and I've confirmed it's not the BBD since I have another fully functioning unit.
I did notice this board is a slightly different layout from my other working unit, dunno if that makes any difference.
The first thing I look for is Resistor values, it's a common mistake when Members are working with similar values.Randomizer from the functioning build didn't affect the non-functioning build, randomizer from the non-functioning build works fine in the functioning build.
Thank you for sharing these! I get strikingly similar bad voltages, at the same points (orange on the image). I also measured voltages at the MCP602 and they look wrong:Here's what I got for voltages in my working unit vs the non-working unit:
There were really only minor differences between most of the values but I highlighted the main differences in red and the parts in the nonfunctioning unit are marked with NF in the header. In the functioning unit there's voltages that are fluctuating, but in the nonfunctioning unit those voltages are static and also a few volts off. For instance terminals 9, 10, 11, and 12 on the CD4046 aren't moving in the NF unit aren't moving and are very different. Also on the LM13700n terminals 6, 8, 11, and 13 are all moving a bit but in the NF unit they're static and about 2 volts higher than they should be. On my MN3207 terminals 7 and 8 are both around the voltages in the functioning unit, they're just not moving.
1 (VoutA): 0V | 5 (VinB+): 2.15V |
2 (VinA-): 0V | 6 (VinB-): 1.83V |
3 (VinA+): random | 7 (VoutB): 5.04V |
4 (Vss): 0V | 8 (Vdd): 5.05V |
Working now! I took the PCB out of the enclosure to check solder joints, and suddenly it was working when checking with an audioprobe! I think the issue was a short at the back of the stereo potentiometer, I did have insulating tape there, but one of the solder joints must have poked through, and made contact with the potentiometer. I'm using a double-layer of tape now, that seems to have done the trick!Tried out new MCP602 chips today, but no luck - voltages are unchanged.
Will report back if I eventually sort out the issue
PIN\IC | IC1 (LM78L05) | IC2 (Randomizer) | IC3(LM13700N) | IC4(LM258) | IC5(MCP602) | IC6 (CD4046BE) | IC7 (MN3207) |
1 | 8.95 | 4.79 | 1.28 | 1.82** | 2.2** | 0 | 0 |
2 | 0 | 5.02 | 5.32 | 2.51 | 2.2** | 2.4 | 2.42 |
3 | 5 | 5 | 4.73 | 2.49 | 1.7** | 2.45 | 1.71 |
4 | 0 | 4.73 | 0 | 0 | 2.45 | 4.7 | |
5 | 2.18** | 5.87 | 1.7 | 2.2 | 0 | 5.02 | |
6 | 5.02 | 0 | 1.7 | 2.2 | 0.694 | 2.42 | |
7 | 5 | 5.87 | 1.7 | 2.6 ** | 0.694 | 1.83 | |
8 | 5 | 4.71 | 8.95 | 5.02 | 0 | 1.91 | |
9 | 4.66 | 2.2** | |||||
10 | 5.92 | 2.2** | |||||
11 | 8.96 | 0.3 | |||||
12 | 5.92 | 3.22 | |||||
13 | 4.72 | 0 | |||||
14 | 4.72 | 5.02 | |||||
15 | 5.31 | 1.14 | |||||
16 | 1.276 | 5.02 |
I think I read somewhere that you shouldn't have both dip switches engaged (on the right), not sure if that would affect modulation.Just finished a low tide and I'm getting the same problems of the OP (audio signal passing through when engaged but no modulation),
below are my voltages:
PIN\IC IC1 (LM78L05) IC2 (Randomizer) IC3(LM13700N) IC4(LM258) IC5(MCP602) IC6 (CD4046BE) IC7 (MN3207) 1 8.95 4.79 1.28 1.82** 2.2** 0 0 2 0 5.02 5.32 2.51 2.2** 2.4 2.42 3 5 5 4.73 2.49 1.7** 2.45 1.71 4 0 4.73 0 0 2.45 4.7 5 2.18** 5.87 1.7 2.2 0 5.02 6 5.02 0 1.7 2.2 0.694 2.42 7 5 5.87 1.7 2.6 ** 0.694 1.83 8 5 4.71 8.95 5.02 0 1.91 9 4.66 2.2** 10 5.92 2.2** 11 8.96 0.3 12 5.92 3.22 13 4.72 0 14 4.72 5.02 15 5.31 1.14 16 1.276 5.02
And my pedal:
View attachment 22473
I would start a new troubleshooting thread with pictures of both sides of the board and any component substitutions you may have made.I built two of these, one for myself and one for a friend and neither of them seems to work at all. I get a clean signal when the pedal is plugged in but not engaged. When I engage the pedal the sound completely disappears. Dead. No knob makes any difference, nor does adjusting bias or gate.
I’ve poked at both a bit the past while but tonight I took one out and touched up every solder joint, checked orientation of the chips, attempted adjustment of bias, gate, and the switch… still nothing. No sound passes through when it’s engaged. I just find it odd that the same issue is plaguing both pedals. I built two but consecutively rather than at the same time so it would be odd to make the same mistake twice if it were misorientarion of a component.
Any ideas? Burnt a chip somehow? Is there a way to test that?
Ah yes, an audio probe. Been meaning to build one for a while anyway, no time like the present. Thanks for putting that idea back in my head!Verifying the power and ground at the ICs is a good start. Then make sure you have good connections from the pedal switch that go in and out of the pcb. After that your best tool to isolate where your audio signal is getting stopped is to build an audio probe. Do a search on "audio probe" in the forums here and you will get pointed to some good resources. Easy to make and essential for tracking down problems in a build.
Thanks, I am gonna start with building an audio probe as suggested and see if I can figure it out first. I wouldn’t mind improving my troubleshooting skills rather than just running off for help anytime something doesn’t work. Haha. But if I am still having issue I will do as you suggest. Thanks!I would start a new troubleshooting thread with pictures of both sides of the board and any component substitutions you may have made.