Clandestine (Chase Tone Secret) noise increases when putting on back lid

[harmaes]

I build a Clandestine preamp yesterday and its quite a nice pedal.
I got around 23v on R101 and I set the bias to around 13.9v (just right of center of the trimpot) which is about 60%.
The pedal operates well and the 3 EQ presets work nicely.

I noticed something very peculiar which I've never seen before. When the pedal has no back lid and is top facing down or on it's side, the noise is less then when the pedal is in it's normal position. The stranger thing is that the noise (hiss, crackling) increases when I put the lid on (without screws)?

I tried 4 different power supplies (cioks, strymon ojai and strymon general power supply) but it's not related to the power supply.
I did have to use one Lumberg jack on the input side because the closed jack didn't fit. I also replaced the output jack with a normal open jack which didn't solve it.
I tried to have the jacks not connected to the enclosure and hanging outside of the pedal while connected but placed the lid only partial over the back already increased the noise. Seems to be some kind of antenna somewhere or something that's slightly connected to ground? I attached 2 pics of my build (not my cleanest as I was too lazy to clean the PCB).

Any ideas what might be causing this and how to solve it?
Next I want to try to replace the single input/output wires with grounded wire because it seems like it's picking up static somehow?

 

[harmaes]

No experiences similar to mine?

 

[Fama]

Do the screws make a difference with the noise?

And did I get this right, the noise changes depending on the orientation of the pedal? So upside down or on it's side there's less noise than when it's facing up? Does the same thing happen with and without the back lid?

I'm not really an expert, but if the orientation has an effect I would suspect it's interference related. Any fluorescent lights you could check to see if they have an effect? Computer you could turn off temporarily (sleep should be enough I think)?

 

[harmaes]

The screws don't make a difference. The position indeed changes the noise and normally placing the lid it should become a Faraday cage which should reduce noise instead of increasing it. Even placing the lid half over the back introduces noise.
I will replace the single wires next because maybe they're acting like antennas.

It's not related to computers or fluorescent lights which I don't have. Thanks for your help!

 

[Fama]

The screws don't make a difference. The position indeed changes the noise and normally placing the lid it should become a Faraday cage which should reduce noise instead of increasing it. Even placing the lid half over the back introduces noise.

Yeah, that's what I thought should happen. Do the input/output jacks make connections to the enclosure? I'm not sure if powder coating conducts electricity, is it possible that nothing is grounded to the enclosure?

 

[music6000]

Hi Harry
The original recommends 9v Only so 17 t0 18v max internally, are you running a 12v power supply.
It looks like everything is correct in your build but I don't think the TC1044 is meant to take that voltage???
Are your Electro caps larger than 25 volt?

 

[harmaes]

Yeah, that's what I thought should happen. Do the input/output jacks make connections to the enclosure? I'm not sure if powder coating conducts electricity, is it possible that nothing is grounded to the enclosure?

Outut jacks indeed make contact to the enclosure.
I replaced the input/output wires with grounded wire and that reduced the noise of the pedal in general.
It didn't solve the added hiss coming from placing the back lid.
I did notice that when holding the lid over parts of the back of the pedal it didn't introduce hiss on the 3PDT nor the jacks areas.
It only introduced noise when holding the lid over the middle and of course when holding it over the complete pedal without screwing it on.

@Robert @MichaelW Maybe it's an issue more people have but because I listen with headphones I hear it immediately?

 

[harmaes]

Hi Harry
The original recommends 9v Only so 17 t0 18v max internally, are you running a 12v power supply.
It looks like everything is correct in your build but I don't think the TC1044 is meant to take that voltage???
Are your Electro caps larger than 25 volt?

I use 9v power supplies (Cioks, Strymon Ojai and Strymon 9v all purpose. The latter was better then the 2 others having only like white noise introduced very lightly where the others have white noise and a light crackling.

The Elco's are all exactly 25v. Could this be the issue because the noise also increases exactly over the elco caps?

Could this also be a noisy 2n5457 or TC1044?

 

[Fama]

@Robert @MichaelW Maybe it's an issue more people have but because I listen with headphones I hear it immediately?

FWIW I built mine without the 2N5457 at first since a shipment was delayed, and struggled with noise. But once I got a 2N5457 there isn't much extra noise added - there is a very tiny amount, but about what I would expect from added saturation on the signal. But I also listen with headphones, am picky about noise and have a bunch of mixing experience, so I'm pretty sure I would have noticed crackling issues.

Here's how mine sounds with noise gate turned off (I have a bass plugged in right now, I played a few notes just so you can get a sense of how loud it is compared to the bass signal)

https://soundcloud.com/user-913671490%2Fclandestine-noise%2Fs-5W3SDbx60Md

First without, then you can hear a small pop when I turn the clandestine on. Not really any noisier. Similar results with the bass volume turned off, the background noise tone changes a tiny bit (as one would expect with the EQ in it), but not really more noise at all. I think my noise is probably the self noise from the preamps on the Quad Cortex? Or just electrical interference. I have a huge pedal board too.

I normally use a very subtle adaptive gate, which cuts the noise out completely, and I don't notice it at all.

 

[harmaes]

The ICL7660S and LT1044 both aren't compatible with the TC1044SCPA right?

​

 

[harmaes]

The noise without the back lid on is similar to most drive or boost pedals.
Adding the back lid introduces quite some white noise/hiss like a compressor that's turned up.
So I can better add a plexi back panel and put the pedal on it's side?

 

[harmaes]

I can order a few 2n5457 to see if some are better then others as well.

 

[harmaes]

FWIW I built mine without the 2N5457 at first since a shipment was delayed, and struggled with noise. But once I got a 2N5457 there isn't much extra noise added - there is a very tiny amount, but about what I would expect from added saturation on the signal. But I also listen with headphones, am picky about noise and have a bunch of mixing experience, so I'm pretty sure I would have noticed crackling issues.

Here's how mine sounds with noise gate turned off (I have a bass plugged in right now, I played a few notes just so you can get a sense of how loud it is compared to the bass signal)

https://soundcloud.com/user-913671490%2Fclandestine-noise%2Fs-5W3SDbx60Md

First without, then you can hear a small pop when I turn the clandestine on. Not really any noisier. Similar results with the bass volume turned off, the background noise tone changes a tiny bit (as one would expect with the EQ in it), but not really more noise at all. I think my noise is probably the self noise from the preamps on the Quad Cortex? Or just electrical interference. I have a huge pedal board too.

I normally use a very subtle adaptive gate, which cuts the noise out completely, and I don't notice it at all.

In your demo the Clandestine doesn't introduce noise. I do hear what I would call a light crackle and some pedal noise (or PS noise?) coming from a different pedal or QC?

 

[music6000]

I use 9v power supplies (Cioks, Strymon Ojai and Strymon 9v all purpose. The latter was better then the 2 others having only like white noise introduced very lightly where the others have white noise and a light crackling.

The Elco's are all exactly 25v. Could this be the issue because the noise also increases exactly over the elco caps?

Could this also be a noisy 2n5457 or TC1044?

I have confirmation that your pedal does run at the Voltage you describe in this design, so I don't know if your electro's may be an issue.
I run minimum 35v Electro's on all my pedal builds even at 9v internal.
the ICL7660SCPAZ is my choice of Charge pump instead of the TC1044S!
If you have a ICL7660S, use that & see if your issue goes away.

 

[harmaes]

I ordered an ICL7660S and a few other 2n5457.
The build document mentions 25v minimum except for c100

 

[Fama]

FWIW I run a TC1044SCPA from Tayda, I don't remember the electro's, might be 25V.

 

[harmaes]

FWIW I run a TC1044SCPA from Tayda, I don't remember the electro's, might be 25V.

It’s quicker to order in the Netherlands.

 

[harmaes]

I had a 7660S in my stack but changing it didn't make a difference. I did notice that the voltage of the 7660S probably is lower because the output was reduced.
Noise still occuring when placing the pedal on a flat surface without lid open side facing down or when placing the lid on it and even when putting my hand across the open side.

Here's the noise I get with 2 adapters, holding the pedal upside down with no back cover, turning the pedal to the floor with the open side. First one adds hiss, second one adds a crackling sound. The noise at the end is when I place the lid on at the back where my hand touches something that increases the noise. Quite unusable this way.

https://soundcloud.com/har-maes%2Fclandestine-noise%2Fs-YEzH05M0wh8

 

[music6000]

I had a 7660S in my stack but changing it didn't make a difference. I did notice that the voltage of the 7660S probably is lower because the output was reduced.
Noise still occuring when placing the pedal on a flat surface without lid open side facing down or when placing the lid on it and even when putting my hand across the open side.

Here's the noise I get with 2 adapters, holding the pedal upside down with no back cover, turning the pedal to the floor with the open side. First one adds hiss, second one adds a crackling sound. The noise at the end is when I place the lid on at the back where my hand touches something that increases the noise. Quite unusable this way.

https://soundcloud.com/har-maes%2Fclandestine-noise%2Fs-YEzH05M0wh8

Where did you get the 2N5457?
I summize it's suppose to be Central Semiconducter ???

 

[harmaes]

Musikding.

I noticed I have 2 in my stack and ordered 3.
I need to remove the current one first which is always a pain.

I have one similar like yours (CEN) and the other one has an F at the top.