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How to fix the LFO tick in the Sea Horse and Dark Rift

Chuck D. Bones

Well-known member
I've found a simple circuit mod that gets rid of the LFO tick in the EQD Sea Machine (Sea Horse) and Space Spiral (Dark Rift). It has been tested on both pedals. It's the same mod for both pedals, only the ref designators are different.

Sea Machine:
Remove C19.
Connect a 10nF cap between pins 1 and 2 on IC4. A small MLCC on the back side is a clean way to do it.

Space Spiral:
Remove C30.
Connect a 10nF cap between pins 6 and 7 on IC5. A small MLCC on the back side is a clean way to do it.

In theory, a mod of this sort should also work on the Chaos Machine & BiPhase. It requires more surgery on those two pedals and has not been tested (yet).
 
Last edited:

dawson

Member
That's awesome- thanks a lot!
I haven't started my Chaos Machine yet, but I'll be building it soon, so I can offer to help testing that one. I'm no more than a "cowboy" with the circuitry, but I've got a nice multi-meter and I follow instructions.
 

cooder

Active member
Excellent! I'm keen to hear how this could work on the BiPhase as mine ticks a wee bit on higher settings! And great to know for the other circuits too of course! Thanks!
 
Would anyone mind showing off a photo/schematic of your mods for the ticking?

These might be obvious:
- When you say "remove C19..." - remove the cap and leave the gap wide open?
- When you say "connect a 10 nF cap..." - is the only mod a MLCC cap soldered directly on the underbelly of the pcb, in between pins X and X?
 

Nostradoomus

Well-known member
On the Sea Horse yes leave it open, the circuit is completed with or without C19 there. Haven’t seen the dark rift schematic but I’m imagining the LFO section is similar. You could technically have the cap running on the top side of the board from pin 1 facing side of R24 over to the pin 2 end of R21 I think, but it’s much nicer looking and easier to just do it on the bottom of the board.

0C5B2BBE-A002-404E-80CA-64302802E543.jpeg
 

PedalPCB

Administrator
Staff member
Haven’t seen the dark rift schematic but I’m imagining the LFO section is similar.
Virtually identical.

Very grateful for the work you guys did here!

These modifications will be worked into both PCBs in the upcoming weeks. Both boards will be marked "Rev1.3" on the back to identify that the changes have been made.

Excellent! I'm keen to hear how this could work on the BiPhase as mine ticks a wee bit on higher settings!
If your Duo-Phase ticks on the right side only (looking at the face of the enclosure) you might want to try rerouting the wire to the input jack. It's prone to picking up LFO noise. I've never known the other side to tick, and moving the wire has always cured the issue. With that said, this is certainly a welcomed modification if it helps. (y)
 

Nostradoomus

Well-known member
Virtually identical.

Very grateful for the work you guys did here!

These modifications will be worked into both PCBs in the upcoming weeks. Both boards will be marked "Rev1.3" on the back to identify that the changes have been made.
Very cool!

Also if you have discounted old revisions I’ll take some :D
 

Bobbyd67

Active member
I've found a simple circuit mod that gets rid of the LFO tick in the EQD Sea Machine (Sea Horse) and Space Spiral (Dark Rift). It has been tested on both pedals. It's the same mod for both pedals, only the ref designators are different.

Sea Machine:
Remove C19.
Connect a 10nF cap between pins 1 and 2 on IC4. A small MLCC on the back side is a clean way to do it.

Space Spiral:
Remove C30.
Connect a 10nF cap between pins 6 and 7 on IC5. A small MLCC on the back side is a clean way to do it.

In theory, a mod of this sort should also work on the Chaos Machine & BiPhase. It requires more surgery on those two pedals and has not been tested (yet).
If you get the chance to look around the chaos machine lfo ticking it would be greatly appreciated !! Got 2 builds in the bin because of the ticking... Tried shielded wires and new sets of op amp from mouser and it still ticks even in bypass :( !!! Thanks for all your hard work !
 

neil463

New member
Virtually identical.

Very grateful for the work you guys did here!

These modifications will be worked into both PCBs in the upcoming weeks. Both boards will be marked "Rev1.3" on the back to identify that the changes have been made.



If your Duo-Phase ticks on the right side only (looking at the face of the enclosure) you might want to try rerouting the wire to the input jack. It's prone to picking up LFO noise. I've never known the other side to tick, and moving the wire has always cured the issue. With that said, this is certainly a welcomed modification if it helps. (y)
Can you make sure the legacy build doc also remains available to be able to reference the schematic,etc. prior to the fix?
 

Dali

Well-known member
A mlcc capacitor is a smaller size than a the box type we usually use in a build. Tayda has them. Here is a pic https://media.rs-online.com/t_large/R5381310-01.jpg
I realize my comment was open to interpretation. I was asking for a look of the modification itself, not the part.

English is not my main language... Sorry.

I can imagine how it will look but sometimes I learn a better way to do stuff by seeing exemples and builds from people here.
 
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