SOLVED Relay Bypass (latching) + Informant: Effect always-on, LED switches on/off

[Lytt Effects]

EDIT: SOLUTION - incorrect part was ordered for the relay. This board requires a 5v latching relay (EA2-5SNJ), but I accidentally ordered and installed the EA2-24NU, which is a 24v latching relay. Moral of the story is: triple check your part numbers when ordering, and always use sockets.

Ok y’all, need help with my first go at a relay bypass. I am using it with the Informant PCB (1981 DRV) and have it wired up in buffered bypass (In Jack to PCB In > BP to Relay In). The LED is switching on/off as normal, but the effect stays on no matter what.

So far, I have ensured all components on the relay bypass board are the correct value, orientation, etc. but please double check me. I also triple checked the 3904/3906 locations. I also swapped in a different relay to no avail.

Many pictures:

 

[jimilee]

is it a non latching relay?

 

[Lytt Effects]

is it a non latching relay?

Board is the latching relay board. Relay itself is the Kemet EA2-5SNJ latching relay bought from PPCB. Listed as a substitute for the TQ2-L-5V called for in the build docs.

 

[pbrommer]

Honest question: am I seeing things, or is there no wire connected to the IN of the relay board? I can’t tell and maybe the coffee hasn’t kicked in. Maybe that’s it?

 

[Lytt Effects]

Honest question: am I seeing things, or is there no wire connected to the IN of the relay board? I can’t tell and maybe the coffee hasn’t kicked in. Maybe that’s it?

You are not seeing things haha. There is in fact nothing connected to the IN pad of the relay board, but that’s intentional. I wanted to use this in buffered bypass, which means the tip of the IN Jack needs to go to the IN of the effect PCB. Then the BYPASS pad of the effect PCB (buffered bypass) goes to the IN (jack - far left) pad of the Relay PCB. Since it’s going directly into the effect PCB IN, the IN pad on the relay board is obsolete.

I guess I could try re-wiring it for True Bypass to see if something is going on there, but it’s strange to me that it’s switching the LED on and off like normal, but the effect remains activated no matter what. I will also be pulling the whole thing out to see if maybe there’s a short or bridge that’s somehow connecting the BP/buffered section of the schematic into the effect signal.

 

[gtfields13]

I think I am following your logic, with taking the buffered bypass off of the effect PCB. As a matter of troubleshooting, setting it to true bypass will confirm that this is not the issue.

Alternatively, if you remove the input (form Effect PCB) to the relay board (but leave your in-jack wired to the Effect PCB) and either put nothing or a test signal as input to the Relay PCB, you can establish whether the audio signal side of the relay is functioning. You should detect the relay switching from passing it's input directly to the audio output or passing the "out" signal from the board.

I think (not sure) that there is a separate throw for the LED than for the audio, so you could have a bad relay on the audio signal path and still see the LED flashing on and off.

 

[PJS]

Looking at the 2 different switch wiring schemes I do not think this bypass board could do the buffered bypass method. The traces hard wired into the PCB are going to be different enough not to allow buffered bypass. I am not sure whether or not Pedal PCB sell one to do it. You could do up your own and get it made if you wanted to. Otherwise you may be able to cut some tracks and re-wire them.

 

[Lytt Effects]

is it a non latching relay?

Allow me to re-answer this, if you will.

No, it is not a non-latching relay. Yes, it is a latching relay. HOWEVER, some dumbass didn't doublecheck the part number when ordering, and apparently did NOT order these relays direct from PPCB.

I woke up this morning and realized that I had ordered an EA2-5SNJ a while back with the Intelligent Relay Bypass board/micro-controller, which was direct from PPCB. For this order though, I needed to get some stuff from Mouser, so I ordered them from there since it was cheaper. It dawned on me that I may have accidentally ordered the incorrect relay, so I ran down to the basement, opened up the relay I ordered from PPCB that was tucked away with the Intelligent Relay Bypass board to compare, and sure enough, wrong part.

I swapped in the correct relay, and voila, it works! What a time to be alive. I somehow accidentally ordered the EA2-24NU, which from a distance are almost identical to the EA2-5SNJ, but require 24v for the coil voltage, as opposed to 5v for the EA2-5SNJ. Whoops! Thankfully, Mouser is very good about returns, and is actually issuing me a credit without having to return the incorrect parts even though it was my fault.

 

[jimilee]

Woohoo! I love it when a plan comes together.