Low Tide No Signal - Schematic?

[Edenspace]

Coming back to this problem build after some time away from pedal making. This one has been an issue for a bit so sorry for the lack of

1. Signal passes when footswitch is not engaged, no signal when engaged
2. With volume pot up, turning up the mix knob causes a soft wave of white noise to pass
3. No other knobs or boost/pad dip switches cause audible changes to that white noise
4. No amount of changing internal trim dials creates audible change

Looking for a schematic to go through and test voltages but have not been able to find one. Any help is appreciated.

 

[Feral Feline]

Maybe while you were on hiatus, somebody experienced a similar problem and has a solution.
Have you searched the Low Tide threads since coming back?

I'm guessing you haven't, or you would've found the schematic, too.
Here:

Low Tide Modulator - PedalPCB.com

Compare to Fairfield Circuitry Shallow Water

www.pedalpcb.com

Looking for a schematic to go through and test voltages

I was wrong, you have looked.
Here:

Post in thread 'Low Tide Schematic?'

Nov 8, 2023

Has anyone made a low tide schematic?

https://docs.pedalpcb.com/project/LowTide-Schematic-PedalPCB.pdf

• Robert

• 

Here:

C

SOLVED Thread 'Help with Low Tide schematic'

Oct 22, 2024

My problem: everything about the pedal works very well and as expected (or unexpected) EXCEPT the gate pot changes nothing at all in the sound CCW or CW. Gate trimmer ditto, full CW or CCW, no change.

https://docs.pedalpcb.com/project/LowTide-Schematic-PedalPCB.pdf

Checked continuity of everything from the transistor before the gate pot to the transistor after, and all is connected.

What I need help in understanding is whether I need to proceed further down the schematic to investigate what could be non-functioning in the gate control. Does the downstream bit with the LM258P and...

• comradehoser
• Replies: 13
• Forum: Troubleshooting

no signal when engaged

I'm guessin' it's to do with the switch. Try reflowing the connections on the breakout-board and to the main PCB.
Allow lots of cooling time between lugs.


Have you got an audio probe?

 

[Erik S]

Hard to tell from the photo, but is pin1 of your CD4046 bent under?

 

[Edenspace]

Hard to tell from the photo, but is pin1 of your CD4046 bent under?

View attachment 91338

Pin 1 is in there, just the angle of the photo and the way it is bent into the socket a bit.

 

[Edenspace]

Maybe while you were on hiatus, somebody experienced a similar problem and has a solution.
Have you searched the Low Tide threads since coming back?

I'm guessing you haven't, or you would've found the schematic, too.
Here:

Low Tide Modulator - PedalPCB.com

Compare to Fairfield Circuitry Shallow Water

www.pedalpcb.com

I was wrong, you have looked.
Here:

Post in thread 'Low Tide Schematic?'

Nov 8, 2023

Has anyone made a low tide schematic?

https://docs.pedalpcb.com/project/LowTide-Schematic-PedalPCB.pdf

• Robert

• 

Here:

C

SOLVED Thread 'Help with Low Tide schematic'

Oct 22, 2024

My problem: everything about the pedal works very well and as expected (or unexpected) EXCEPT the gate pot changes nothing at all in the sound CCW or CW. Gate trimmer ditto, full CW or CCW, no change.

https://docs.pedalpcb.com/project/LowTide-Schematic-PedalPCB.pdf

Checked continuity of everything from the transistor before the gate pot to the transistor after, and all is connected.

What I need help in understanding is whether I need to proceed further down the schematic to investigate what could be non-functioning in the gate control. Does the downstream bit with the LM258P and...

• comradehoser
• Replies: 13
• Forum: Troubleshooting

I'm guessin' it's to do with the switch. Try reflowing the connections on the breakout-board and to the main PCB.
Allow lots of cooling time between lugs.


Have you got an audio probe?

I do have an audio probe, just need the schematic to help diagnose. I'll try the switch but its just odd that theres not even dry signal that passes, just noise floor hiss.

 

[Feral Feline]

Yeah. If it was truly dead at the 3PDT, you shouldn't even be getting hiss.

I still think it's early on as none of the controls were doing anything; how can they if they're not getting signal.
With the audio-probe you can check the 2SK208-Y, as that comes right after the input and if it is not soldered well, that could explain the lack of proper signal and hiss.

Simple things such as reseating the 2N3904s in their sockets. (I've not had problems with sockets but other forumites hate them with a passion).


Pay no mind to me, I'm just mutterin' aloud:
Looking at the 3207's Datasheet and at the Low Tide Schematic ... Hmm Pin2 "CP4" of the 3207 goes to the CD4046's pins 3&4 (CIN / VCO OUT) and then the 4046 goes back, via its pin-2 PC1, to 3207's pin6 CP2.
Makes me realise I'm lost already and don't understand the circuit. Is the 4046 carrying any audio, or is it just modulating the 3207?

AUDIO PATH...
IN > 2SK208-Y > 2N3904 > LM258P > V3207D > LM13700 > J201 > 2N3904 > OUT



Per Erik S's post — Have you a spare CD4046BE ? Maybe the one that's in the build now got zapped with some ESD.