Simplest relay bypass possible - no microcontroller (latching) - HELP

[equinox]

Having issues with these boards!

I purchased a bunch of these from Buggs for making an 8 channel strip true bypass looper utilizing clickless momentary trigger.
I'm getting a a "click" "click" when it is engaged or disengaged! I'm using the Latching version and hooking it up like Buggs said without the one transistor and LED hooked up to where the transistor would be.

I'm not hooking these up to one of PedalPCB pedals, but some commercial pedals.

At first I wasn't getting signal, then I figure out the IN and OUT. I figured the out of the pedal would go into the IN, but no, it's as labeled and Out of the pedal needed to go to the OUT of the circuit. I thought maybe grounding issue and messed with that, but still having issues. It isn't quiet either. Not sure what is up, but contacted Buggs twice and supplied detailed question along with video and did not get a response!!

I need this solved. Been working on this for months!! Any help would be greatly appreciated.

ref: bypass unit - https://www.pedalpcb.com/product/pcb394/
ref: chirp - https://drive.google.com/file/d/1_5WZkwMOaLkKlSksKnjR6n2gM8NfrAyV/view?usp=sharing
ref: noise - https://drive.google.com/file/d/1Glzb0FZ6kHxTSxtpiBw32yMHYiM8ONH6/view?usp=sharing
ref: grounding and hook up: https://drive.google.com/file/d/1s5WxQP6LoXhJD7vDppYt9QPzVc8M7STb/view?usp=sharing

 

[Robert]

Howdy! You're emailing an address that isn't checked daily and with all of the website / forum notifications emails tend to get buried pretty quickly anyway. The forum is the best way to go because it's harder for me to miss.

The sound in your "chirp" clip sounds like the relay contacts bouncing to me. If you replace the pedal that is being switched with a patch cable (directly from Send > Recv) do you still hear the same chirp?

 

[equinox]

k. Thanks soo much for getting back. Let me know when email is current. Thanks.

Yeah, it's Saturday, so after breakfast, I'm going to be getting on this first-thing and can report back.

Thanks for letting me know the forum is a primary place to post for support also.

Yeah, that's what I thought also...relay "bouncing". I'll check into it.

Let me know about the grounding. I was worried about that also as the board only had the tip, so am not sure if gets grounded to the board ground or how!! It'll need a ground reference I would think, but may be wrong.

 

[equinox]

Ok Buggs, built up a completely new board (https://drive.google.com/file/d/1NzGZUeRNpwnt1S9-dPEFQQZZroIboLlc/view?usp=sharing) as I originally purchased 8 boards from ya. This time, nothing socketed, so all components directly soldered. I'm powering the unit with an MXR Iso-Brick (https://drive.google.com/file/d/1zIRyilsejOq6trcpj6JcNXec5K5Iv7C5/view?usp=sharing) as I wanted isolated power source(s).

There is no FX in the loop, just the jumper like you suggested for now. I still need your feedback in regard to ground wiring. In this clip, all of the jack (4) grounds are connected, but nothing back to the board and just to each other.

I double-confirmed all component orientation via my Atlas meter for E B C orientation. I'm running the board with 9VDC. For the LED, I'm using these 16mm LED indicators from Tayda (A-4433 - https://www.taydaelectronics.com/16mm-red-led-indicator-pilot-lamp-panel-mount-12v.html). It doesn't seem to matter which way they are plugged into a DC source, they light up! I have taken them apart and there are 2 100 ohm resistors attached to each leg (https://drive.google.com/file/d/1lS-UFGPkbhwQ_BzGQ_CMif7usQVd0H7v/view?usp=sharing).

The relay is switching. There is an audible noise out the speaker, but not the "chirp" previously. If I remove any of the jack ground, there is a ton of noise, so at the very least believe they need to be together. When the pickup is engaged, there is a buzzing noise and for whatever reason, when the circuit is engaged, there seems to be less output and also a rolloff and in the tone, so is not transparent. Does the circuit need to be in an enclosure? (https://drive.google.com/file/d/1Cf1G8HFFXmevS8W_QM-GpO713hof04jZ/view?usp=sharing)

Any help is greatly appreciated. I'm trying to get a circuit that has 6 loops (5 pedals + a master bypass). I further need two isolated circuit that will shunt the tip to sleeve for turning on and off say a space echo, so was going to use 8 of these circuits and did not want a microprocessor-based circuit (if I can) and as long as it switched and was transparent, etc.

PLEASE, YOUR SUPPORT.

 

[equinox]

Anything??

 

[equinox]

{UP}

 

[zgrav]

Why are you using an LED where the transistor should go? And even if you can sub an LED there, I would try it with a regular LED instead of those panel mount lights you are using.

 

[zgrav]

also -- can you add a picture of your footswitch? does it make any clicking noise when you press it? some momentary switches will, most won't.

the schematic you linked shows the ground wire from the switching board connecting to ground on the jacks (green line)

 

[equinox]

"Why are you using an LED where the transistor should go?"
....because that is how the circuit is set up and direction from Buggs, that if using an LED, pull the transistor and put in that place to ground! It's labelled on the back of the PCB "A" for Anode and "K" for Cathode!!

"I would try it with a regular LED instead of those panel mount lights you are using."
Well, I can do that, but I'm using these as loopers for FX pedals, triggered by momentary footswitches and these specific LEDs used and to turn on when engaged! That's why!!

I thought I DID in fact even try standard 5mm LEDs, but this overall project is 2yrs 3mo old and purchased these boards 10 mo ago and can't recall if I did with a pedal and amp hooked up, because initial function was only done and light coming on and hear relay switching, but may have not hooked up pedal/amp that's resulting in the current situation!!

I've hooked up 2 different types of switches. Both are soft touch momentary and make NO click or latching at all!

As far as schematic...what are you referencing the grounding mock up?? Because the switch(es) are hooked up to the FS pins on the PCB. I'd have to see the schematic in Buggs Information file how/what hooked up to, but I'm attaching the pins where they are supposed to be.

 

[equinox]

I just looked at Buggs' schematic and the footswitch interrupts the connection between NE555 pin 2, and one side of R3 (100k resistor) and positive side of C1 (1u) cap. not sure where you're seeing a switch hooked up to ground?!??

 

[Robert]

I'm assuming you got the ground hum worked out?

If the only remaining issue now is the clicking from the relay opening/closing you might need to look at a relay module with some form of click/pop suppression...

These are generally quiet enough for most purposes, but if it's unacceptable for your use there isn't a heck of a lot you can do to improve it... even the Intelligent Relay Bypass module has no form of mute circuit so it might not be what you want either.

 

[equinox]

no. there were 3 issues...

1. is the grounding hooked up right and all jacks connected and then go back to the bard ground? Wondering if there is a ground loop somewhere.
2. the popping when engaged/disengaged
3. If you watch the video, even though the FX IN and OUT were jumped, there was a difference between ON and OFF states and with a roll off of the top end!!

Check out how everything is hooked up in this layout https://drive.google.com/file/d/1s5WxQP6LoXhJD7vDppYt9QPzVc8M7STb/view?usp=sharing Is anything out of order or need to be changed/not hooked up right, etc??

I dont get it. It's a simple circuit and besides different indicator, using it to switch in and out an effect that is always on and when out, circuit shunts to ground to quiet it. With IN and OUT jumped, there should be no difference in tone!

Because the indicator works in both directions, I wonder if that is having some effect on the circuit?!?

Do I need a diode in line with the panel indicator to ensure flowing only in one direction?
Is the grounding hooked up correctly?
What about diode or diode/cap across the coil of the relay??

Man, I really need this going and should work as using as a looper as intended

 

[zgrav]

was the schematic that you linked to the one that you are talking about? I am assuming that is the case, but if so it clearly shows the board ground connecting to the ground on the jacks.


those panel mount LEDs seem to have small circuit boards on them in the pictures from Tayda. those can be a noise source in the circuity. I would try using regular LEDs in those spots to see if that clears up some of your problems.

the audible click in your video is not an electronic pop, just a mechanical noise, right? it sounds louder than any relay click I have ever heard from a soft footswitch and sounds more like a hardware click from a footswitch. can you post a pic of your footswitch?

other than the ground question and extra noise, the switch is otherwise working, right?

There are some other steps you can try. If the click is from your relay, it will be quieter when boxed AND your enclosure may give you better noise shielding as well. you might even be able to put some type of hard foam or something between the relay and the enclosure to dampen the sound a bit more.

 

[Robert]

With IN and OUT jumped, there should be no difference in tone!

There definitely should not be. There is nothing in the signal path aside from the relay. If you hear a difference in tone you either have a bad relay, bad jack, or the wiring is incorrect.

There is nothing else on the bypass PCB that could affect the audio path.

 

[Stickman393]

1) grounding looks good.

2) this is something that tends to happen with true bypass switching schemes. If there's any way the circuit you're switching to/from perhaps has a leaky coupling cap in the circuit, that could contribute to a popping sound when you're switching...but if it's happening while the input/output is jumpered, that's probably not what's happening.

I haven't had an opportunity to actually hear what you're referring to here...there are other designs that may be better options for those that are particularly sensitive to switching noise.

3) high end roll off...the actual signal path of this circuit behaves in much the same way that a 3pdt switch would. There's a possibility that the input/output 1/4" jacks or jumper cable are contributing additional capacitance in your signal path: that could be causing a bit of high end to roll off.

In this case your signal is going directly through the relay from input-to-output jacks when in bypass, but you're inserting additional wire and connectors when the relay is active. These two signal paths are not exactly identical: a closer approximation would be to jump the "send" and "receive" pads on the PCB itself.

Noise is normal on a PCB if it isn't boxed. The enclosure acts as a faraday cage: it keeps electro-magnetic interference away from the circuit. Laying out in the open, there's nothing to stop that noise from effecting your signal.

 

[equinox]

Thanks soo much for the feedback guy. I'm making breakfast, have grocery shopping to do, then will delve back into this and based on your feedback.

I'll also look at like I said, some ideas I have, like the diode across the coil and possibly a cap (.047uF) like done on amps with channels relay switched. Have to look up the spec sheet and see what pics need to focus on.

I'm a little puzzled as it's a simple circuit and should work. The main issue is usually debounce and not getting good triggering, BUT it is doing it exceptionally well and why want to use this circuit....no micro, no mis-triggers, and when disengaged, shunts the output to ground, so no crosstalk.

I need to find out what's causing the problem. Is it that weird panel indicator which may have electronics on it and why thou LED-based, works either way wires are hooked up?

Yeah, since popping occurs with different switches, doubt that has anything to do this it.

Enclosure may be needed, but in the one, I DO have it for the most part in a chassis, so shouldn't be an issue also. I needed the grounding scheme confirmed as wasn't sure and if all jack ground get connected to each other and if so, is that it, or do they get connected back to the ground of the board or "-" ground of the battery. That's why I wanted Buggs to confirm. If grounding not right, could cause noise, ground looks and humm, etc. I'll let you know what I find out shortly.

 

[equinox]

I think I may have figured it out after playing around for about 4hrs during the Super Bowl!

There were a few problems...the 1/4" cables seemed to have problems, so cut and soldered it myself.
I had a couple cables hooked up to the power supply, but one, I had modified and positive and negative swapped!
Enclosing makes a difference and this circuit really needs the enclosure and faraday grounding.
There is no issues with the switch or footswitch.
The panel indicator seems to work perfectly and great intensity level. instead of the 10k resistor load, just need to jump it as there is enough resistance with the 100 ohm in the LED housing.
I actually in one hook up had all the jack ground connected, but not back to the PCB.

I'll know more this week, but it appears to be working right now. Pop is at a minimum as well as static and no change in tone now!
I had an YJM OD in the loop and had it in and out of the loop and NO problems. I'll post video when I have confirmed 100%

 

[zgrav]

Glad you are getting the noise issues sorted out.