Please help with my Dual Looper build

[reekosham]

Hi everyone, first time to post here, I have built a dual looper pedal, PCB from Tayda.
It doesn't work at all, no Led light up,
when plugged with Jack cable, without Power cable, super noisy, guitar signal cannot go thru
when plugged with Jack cable and Power cable, noisy, also no signal going thru.
when i touched any of the metal part of the pedal the noise level increased.
I checked all the connections should be correct and firmly soldered...really have no clue what is wrong.

please help, thank you!!!

 

[Mcknib]

Sounds like your powers not wired correctly

It's a passive circuit so should work without power it's just the LEDs that require power

You've either wired your power and ground wrong on the dc jack or from the DC jack to the pcb

Looks like your white power wire on the pcb may be going to the battery power solder pad

 

[reekosham]

Hi Mcknib thanks for the reply, here is the wiring instruction from tayda...

Dual Looper

The Dual Loop allows you to alternate between two different effect loops. It provides two switchable loops (send / return) with a single foot switch.

www.taydakits.com

looks like the power supply wiring is correct!?

 

[Mcknib]

From that yes it looks correct

From their pcb image here, it looks like the 2 bottom pads

Dual Looper

The Dual Loop allows you to alternate between two different effect loops. It provides two switchable loops (send / return) with a single foot switch.

www.taydakits.com

Easy enough to check see if you get continuity between that and the battery + pad, it looks like it does from the pcb trace in your image

You'd also need to make sure your DC jack wirings correct all you need to do is check the voltage on the lugs if you get a minus reading they're inverted

Then you'll know if it's power related or not and can tick it off your list

I've no idea which is tip etc on you audio jacks so didn't trace those

 

[reekosham]

Hi Mcknib,
i actually notice i inverted the sleeve and tip connectio of one jack socket, but after the correction the problem remain the same.
the DC jack is wiring correctly. I think should be the empty DC pad at the left bottom and the + pad at the right.
they are all related to battery power, what should I do with them if I m not intend to use the battery power?
should i ground both pads?

 

[Mcknib]

what should I do with them if I m not intend to use the battery power?
should i ground both pads?

You can use the ground (-) pad if it has continuity with ground, but the (+) pad should be left empty

If you follow the trace from the battery + it looks like it goes to where you have your white power wire (green line)

Use your meters continuity check to see if they do connect if they do then solder your white wire to the other empty power pad

Also check that none of the solder points with the red dots are touching the bare metal of the enclosure

As far as I can see your DC jack is all plastic apart from the nut? and only has 2 solder lugs? The 2 DC jack types in the Tayda documents are switching types with 3 solder lugs, meaning when you plug in your power adaptor it would disconnect the battery and with no adaptor plugged in it would switch to battery power so it looks to me like your 9v white wire goes from DC jack to it's solder pad then over to the battery + pad which is connected to nothing

You may have more than one problem because as I say from the schematic it's a passive circuit that doesn't need power to work the power goes to one pole of your 4PDT with your LED anodes + to either side, your LED cathodes go to their current limiting resistors Rlb and Rla so the power is just to light the LED's

Obviously I don't know the level of your knowledge or experience so just in case here's a brief continuity checking PDF

checking for continuity.pdf

drive.google.com

 

[reekosham]

oh man, you are right about the Green line, so i now connected the empty pad also with the DC power tip, the Leds are working and i m able to switch between A and B.
and sadly you are right about it is not a single problem. the guitar signal still cannot by pass and the electric noise still there. I think it is about the true by pass wiring not correct. the red dots you indicated are not touching any part of the enclosure and I also checked all soldered joints and wires are not touching each other nor the enclosure.
I started wondering if the PCB is actually indicating something wrong.

 

[Chas Grant]

Send B and Return B jacks are swapped and in the pic above, the top jack, on the far right is it wired correctly? It looks like you have white to ring and black to tip, your other jacks are white to tip and black to ring.

 

[reekosham]

@Chas Grant
thanks for helping, the right top jack issue has been fixed.
for send B n return B it is just the positioning thing right? my layout to view from the front of the pedal is
"return B - send B - 9v - return A - send A"
OUT - led b - footswitch - led a - IN

and for the jacks, i have also rerouted all jacks to the other side of tips (all to the right side from the photo's perspective)
wiring should be correct.


really dont know what else could be done as i thought i should be a simple one to complete

 

[Mcknib]

With those type of audio sockets only one side connects, when you insert a jack it lifts one side of the contacts up (NC no connection), so make sure you've soldered your wires to the side that actually connects with the jack, just stick a jack in and continuity check the sleeve with the jack ground solder lug

Looking at your jack socket diagram you've soldered to the wrong side, so a quick continuity check with a jack inserted will let you know, if it beeps that's the side you solder to

 

[Chas Grant]

@Mcknib Nice catch, I didn't even think of that. I've only used those jacks a few times, but I happen to have that board right by me. The ones I have are soldered on the other side. So that just may be it!

 

[Chas Grant]

@Chas Grant
thanks for helping, the right top jack issue has been fixed.
for send B n return B it is just the positioning thing right? my layout to view from the front of the pedal is
"return B - send B - 9v - return A - send A"
OUT - led b - footswitch - led a - IN

and for the jacks, i have also rerouted all jacks to the other side of tips (all to the right side from the photo's perspective)
wiring should be correct.

View attachment 8431
really dont know what else could be done as i thought i should be a simple one to complete

That is just a positioning thing. If that's how you want them, then all is good, it is your pedal! I move jacks all the time. Heck I'm boxing one up now in a 1590B with side jacks. Just my preference.

Another route to take is to check it with an audio probe. It will let you know where you're losing the signal. Easy to build, its just wire, a jack and a 100n cap. Look it up on internet the are all over the place. Then you just follow the route through the schematic until you lose the signal.

 

[reekosham]

yea, i have rewired all the jacks to the correct side. still no luck.
i will try your signal trace problem with the 100n cap.

thanks for the help guys!

 

[Mcknib]

Not that I think it's your problem but you don't need the input jack ring connected with no battery or 2 grounds on the out jack I'd remove the one going to the battery (-) pad

Out of interest what's your test set up are you using 2 pedals to check it, have you got the enclosure the right way up when testing etc with it wrong way up INs on the left

Is it still super noisey

 

[reekosham]

I just removed the cable you mentioned, still the same.
you just reminded me one thing, i have not plugged in anything into A/B, i tried to connect a pedal to A and select using A, the noise went away completely! but still no signal going thru. let me trace the signal lost.

 

[Mcknib]

I just removed the cable you mentioned, still the same.
you just reminded me one thing, i have not plugged in anything into A/B, i tried to connect a pedal to A and select using A, the noise went away completely! but still no signal going thru. let me trace the signal lost.

Yes I didn't think it was the problem just doesn't need wired

I'd set it up fully with 2 pedals to test and trace audio, making sure it's all connected correctly it's very easy to plug guitar in to out when it's upside down, pedal in to rtn instead of snd etc

Snd and Rtn always confuse me

Do you still get noise switched to B?