SOLVED Walrus Julia (PCBGM Julio) help!

[Ale_jellybelly]

Hi all, I know this is a PCB from a (not even particularly liked) competitor, but I've been lurking this community for some time and I figured it's the right place to try asking. I wanted to order a couple of PPCB kits from Musikding but they were out of stock so I went for the PedalPCB equivalent...
Anyways...
I completed the build and even after trying to adjust the trimpot countless times, I can get a nice sound but with a load of background noise and hiss. Also, I can hear a ticking noise that goes on time with the rate knob, and if I turn the amp volume up, I can hear the noise even with the bypassed effect. So I guess I have to redo all of the wiring even if I was sure I did it all right.
Could it be a problem with the ICs? As I said I got it all from a kit so I am pretty sure the parts are all genuine.
Photos and a video of the background noise:

 

[eh là bas ma]

Now the problem is the hiss/background noise when the pedal is on, I can't understand if that's the "normal" noise or not

I think it should be quieter, but i didn't build this.

You can try different dual op-amps for IC4, to compare them and see if it affects the background noise. If it does, i'd suggest to get a TL22.

Background noises can also come from various things : cheap power supplies, bad electrical environment (many power supplies on a power strip), signal impedence, lack of DC blocking capacitor, a component with wrong value somewhere, etc.

An audio probe can be helpful to follow the signal, and find the spot on the circuit where the noise is introduced. Audio probes are among the most useful debugging tools. It's recommended to use a practice amp or a cheap amp, because you easily make popping noises when probing.

Misc > Audio Probe : DIY Fever – Building my own guitars, amps and pedals

[DIY Fever] Audio Probe - very simple contraption that helps with debugging audio circuits

diy-fever.com

Edit: If you're going to audio probe your circuit, your next question should be : "can you show me the signal path on Julio schematics ?"

 

[Ale_jellybelly]

I think it should be quieter, but i didn't build this.

You can try different dual op-amps for IC4, to compare them and see if it affects the background noise. If it does, i'd suggest to get a TL22.

Background noises can also come from various things : cheap power supplies, bad electrical environment (many power supplies on a power strip), signal impedence, lack of DC blocking capacitor, a component with wrong value somewhere, etc.

An audio probe can be helpful to follow the signal, and find the spot on the circuit where the noise is introduced. Audio probes are among the most useful debugging tools. It's recommended to use a practice amp or a cheap amp, because you easily make popping noises when probing.

Misc > Audio Probe : DIY Fever – Building my own guitars, amps and pedals

[DIY Fever] Audio Probe - very simple contraption that helps with debugging audio circuits

diy-fever.com

Edit: If you're going to audio probe your circuit, your next question should be : "can you show me the signal path on Julio schematics ?"

I tried two different decent power supplies and several plugs but the hiss is always present...
I'll try with an audio probe, I don't have a spare jack but I can use a cable right?
I think I should be able to follow the signal path but help is always appreciated, especially around ICs and transistors

 

[eh là bas ma]

This is what i would consider the signal path.

Edit : I made a mistake and forgot to include Q3, correction in orange.

In red is the main signal path, in green the signal path with TL22.

It could also be interesting to compare pcbguitarmania circuit with PedalPCB's, to see if there are some changes with values between these two similar circuits.

https://docs.pedalpcb.com/project/PedalPCB-Caesar.pdf

 

[Ale_jellybelly]

This is what i would consider the signal path.

Edit : I made a mistake and forgot to include Q3, correction in orange.
View attachment 45645
In red is the main signal path, in green the signal path with TL22.

It could also be interesting to compare pcbguitarmania circuit with PedalPCB's, to see if there are some changes with values between these two similar circuits.

https://docs.pedalpcb.com/project/PedalPCB-Caesar.pdf

Thanks for the great help! I'll take a look in the next few days and post an update

 

[Ale_jellybelly]

This is what i would consider the signal path.

Edit : I made a mistake and forgot to include Q3, correction in orange.
View attachment 45645
In red is the main signal path, in green the signal path with TL22.

It could also be interesting to compare pcbguitarmania circuit with PedalPCB's, to see if there are some changes with values between these two similar circuits.

https://docs.pedalpcb.com/project/PedalPCB-Caesar.pdf

I took a look at both schematics and they're the same, with the exception of R100 in Caesar, 10k, and R46 in Julio which is listed as "leave empty" (which I did)... but I can't understand what it does/should be doing
I put together an audio probe, won't be easy following the path on the PCB because the components are a bit all over the place

 

[Ale_jellybelly]

Since my Sea Horse build is missing 7 caps and I'm waiting for the delivery, I've been trying to get back into this disaster of a build
Did a lot of reflowing, rewiring, and pot desoldering and resoldering.
Removed the rate LED
I think I managed to get the noise at an acceptable level.

I'll mess with the trimpot a little bit more this afternoon, then I'll try to box it up

 

[Ale_jellybelly]

Well, i boxed it, taking extra care with the wiring, and of course it's not working anymore.
Probably something in the switch wiring or daughterboard, but anyway ticking is still present in bypass and the noise is still quite high. I'll probably bin the board and salvage what I can to build a PPCB Caesar if I can get Musikding to sell me the board only

 

[Ale_jellybelly]

https://soundcloud.com/ale_s%2Fjuliaaaa%2Fs-9A8B1DFowxl

Got rid of the switch again, and recorded this clip straight into my audio interface. Until 10-12 seconds clean signal (100% dry on the blend knob), then at 14 seconds you can hear the noise start as I turn it around 50-60% and you can hear the noise. At around 30 seconds you can hear the blend going from full wet to full dry so you can hear the background noise. Anyone with experience with this circuit (Walrus Julia/Casear chorus on PPCB) can tell me if it's normal or not?

 

[Erik S]

https://soundcloud.com/ale_s%2Fjuliaaaa%2Fs-9A8B1DFowxl

Got rid of the switch again, and recorded this clip straight into my audio interface. Until 10-12 seconds clean signal (100% dry on the blend knob), then at 14 seconds you can hear the noise start as I turn it around 50-60% and you can hear the noise. At around 30 seconds you can hear the blend going from full wet to full dry so you can hear the background noise. Anyone with experience with this circuit (Walrus Julia/Casear chorus on PPCB) can tell me if it's normal or not?

I just plugged in my ppcb caesar, and it’s dead quiet.

 

[Ale_jellybelly]

I just plugged in my ppcb caesar, and it’s dead quiet.

Thanks that's what I thought
As you can hear the pedal sounds great but it's very noisy

I tried changing the tl072 with a couple of tl022 but it's the same, redid most of the soldering and wiring... What could it be?

 

[sticky1138]

You might want to consider ditching this one, salvaging any worthwhile parts and building the PPCB version. If you haven't already, you're going to end up spending more time troubleshooting than simply building a new one. As a PCBGM board, there's a reasonable chance it will never work properly, so you won't learn any troubleshooting lessons along the way. (I know as the resident PCBGM hater)

The Caesar is one of, if not the best DIY builds I've done, so it's worth it even if you have to pay a little extra to get it to your country.

PPCB did not pay me for this comment

 

[Ale_jellybelly]

You might want to consider ditching this one, salvaging any worthwhile parts and building the PPCB version. If you haven't already, you're going to end up spending more time troubleshooting than simply building a new one. As a PCBGM board, there's a reasonable chance it will never work properly, so you won't learn any troubleshooting lessons along the way. (I know as the resident PCBGM hater)

The Caesar is one of, if not the best DIY builds I've done, so it's worth it even if you have to pay a little extra to get it to your country.

PPCB did not pay me for this comment

Yeah I'm thinking of doing exactly this... I messaged Musikding to see if I can buy the PCB without the kit, if not I'll try to place an order from @PedalPCB. In the meantime I'll take it out again and try with an audio probe.

 

[jwin615]

The ticking goes away when I put the pedal in the chain, it's only there when I play the pedal by itself...
Now the problem is the hiss/background noise when the pedal is on

So no noise when it's in your pedal chain, just on the bench?
If so, that sounds like a grounding issue. Ground is being established by connecting to another pedal.
If you touch the sleeve posts on your jacks, does it go away?

 

[Ale_jellybelly]

So no noise when it's in your pedal chain, just on the bench?
If so, that sounds like a grounding issue. Ground is being established by connecting to another pedal.
If you touch the sleeve posts on your jacks, does it go away?

The noise when bypassed went away when in the chain but the hiss when the pedal was active did not

 

[zgrav]

The noise when bypassed went away when in the chain but the hiss when the pedal was active did not

the hiss may be due to your delay chips. some are noisier than others.

 

[Ale_jellybelly]

the hiss may be due to your delay chips. some are noisier than others.

I have two BL chips, I'll see if I can finally get to test the circuit with my audio probe

 

[Ale_jellybelly]

Some updates on my very old thread:
I ended up buying a proper PPCB board, and gutting the old board of EVERYTHING with the help of my trusty Engineer solder sucker (I even managed to recycle 3 out of 4 IC sockets!)
I built the PPCB board, the ticking was gone, the sound was great but there was still a very noticeable hiss on the background.
In the end I bought a fresh set of Coolaudio ICs (3207+3102), subbed them in and now everything is fine!
what a ride this has been