Low tide help?

spilla

Member
Just boxed. Im getting audio when engaged (also when bypassed) but no noticeable effect. Mix and level knob pots are working, the other pots dont really effect the audio. Any tips on where to go from here? I can post voltages if needed.

Thanks in advance!


tdSz1aL.jpg
 

spilla

Member
Ive 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:

Yeah, it's not terribly difficult. It's rather apparent when you've dialed it in.

I've gather all the comments relating to biasing the low tide:
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


I'll post some voltages tomorrow, is there a way i should set the knobs before i read voltages?

Cheers
 

ElReverendoRyan

New member
Ive 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
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 trim
 

spilla

Member
No, but I have since built it again and had no issues second time around. I do plan to look over the pcb again though. Having a working one will make troubleshooting a little easier. I'll update this thread if I get it working.
 
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WheatAndBarley

Active member
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.
 

clarisso11

New member
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.
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.

Would someone be willing to post IC voltages of a working circuit?

I have seen voltages on other posts, but never for a Low Tide that was working correctly. I think that would be really helpful for many people troubleshooting. Seeing what the voltages at the J201 and 2SK208 pinouts should be would also help to confirm that these are placed correctly.
 

music6000

Well-known member
Randomizer from the functioning build didn't affect the non-functioning build, randomizer from the non-functioning build works fine in the functioning build.
The first thing I look for is Resistor values, it's a common mistake when Members are working with similar values.
Example 47r, 4K7, 47K, 470K ...... 3K3, 33K, 330K

Here is what I use when Troubleshooting
Click on Bands for 5 colours:
 

WheatAndBarley

Active member
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.
 

clarisso11

New member
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.
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:

1 (VoutA): 0V5 (VinB+): 2.15V
2 (VinA-): 0V6 (VinB-): 1.83V
3 (VinA+): random7 (VoutB): 5.04V
4 (Vss): 0V8 (Vdd): 5.05V
With no fluctuating signal coming out of MCP602 pin 7, that explains the CD4046BE pin 9 voltage, and maybe the other voltages as well. I'm getting new MCP602 chips tomorrow, and will share the results.

View attachment 2ahwP4l.png
 
Last edited:

clarisso11

New member
Tried out new MCP602 chips today, but no luck - voltages are unchanged.
Will report back if I eventually sort out the issue
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!
 

pi.cast

Active member
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\ICIC1 (LM78L05)IC2 (Randomizer)IC3(LM13700N)IC4(LM258)IC5(MCP602)IC6 (CD4046BE)IC7 (MN3207)
18.954.791.281.82**2.2**00
205.025.322.512.2**2.42.42
3554.732.491.7**2.451.71
404.73002.454.7
52.18**5.871.72.205.02
65.0201.72.20.6942.42
755.871.72.6 **0.6941.83
854.718.955.0201.91
94.662.2**
105.922.2**
118.960.3
125.923.22
134.720
144.725.02
155.311.14
161.2765.02

And my pedal:

7A4AC30D-5D0B-4390-8447-10674A6CEFBB.jpeg
 

clarisso11

New member
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\ICIC1 (LM78L05)IC2 (Randomizer)IC3(LM13700N)IC4(LM258)IC5(MCP602)IC6 (CD4046BE)IC7 (MN3207)
18.954.791.281.82**2.2**00
205.025.322.512.2**2.42.42
3554.732.491.7**2.451.71
404.73002.454.7
52.18**5.871.72.205.02
65.0201.72.20.6942.42
755.871.72.6 **0.6941.83
854.718.955.0201.91
94.662.2**
105.922.2**
118.960.3
125.923.22
134.720
144.725.02
155.311.14
161.2765.02

And my pedal:

View attachment 22473
I think I read somewhere that you shouldn't have both dip switches engaged (on the right), not sure if that would affect modulation.
Have you tested the pedal outside the enclosure, how are you insulating the dual gang potentiometer from the PCB?
 

WheatAndBarley

Active member
I think I read somewhere that you shouldn't have both dip switches engaged (on the right), not sure if that would affect modulation.
Have you tested the pedal outside the enclosure, how are you insulating the dual gang potentiometer from the PCB?
From the manual they say for guitar it's Boost on (switch to the left) Pad off (switch to the right). It only affects the input gain and impedance if you get too much clipping or want to use it with something line level like a synth.
 

WheatAndBarley

Active member
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!
I will have to double check this and see. I don't believe I have any insulation on my functioning unit under the dual gang pot but it's certainly a possible issue.
 
It took me a few hours to configure the trim pots. I got pretty frustrated but stuck to it. I believe it was the gate pot that I cranked all the way up then dialed back eeeeever so slightly each time between testing it to get the pedal to work properly. Everywhere in between was either little to no effect or it sounsed bad. The other one I just dialed according to my preference.

I'd suggest finding the manual for the orig Fairfield model so you can better understand the pots and how they relate to one another. This is a fantastic pedal it just not exactly plug and play. It took me a little time to understand how to use it.
 
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