Intermittent distortion

pofofo · 3068

0 Members and 1 Guest are viewing this topic.

Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19694
Reply #15 on: July 15, 2021, 05:09:04 AM
Try putting your phone on airplane mode to see if that takes the noise out, or make a recording and post it here.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline pofofo

  • Jr. Member
  • **
    • Posts: 42
Reply #16 on: July 15, 2021, 07:44:49 PM
Good idea. I´ve been trying to record it, but it comes and goes pretty fast and sometimes not at all, so it´s a bit hard.

Yesterday while using another amp, my phone got unplugged and I plugged it back in without lowering the amps volume or removing the headphones from my head: That actually made a similar sound to the noise in the S.E.X, but a bit lower in volume. So the noise is kind of similar to that crackling you get when you plug in or out the jack from a live amp. And earlier I´ve had some imbalance issues with speakers which I traced to the jack plug not "closing" proper to send signals to the speaker post.

I guess I should resolder the wires to the jack once again and maybe clean it out. Or maybe just change it out?



Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19694
Reply #17 on: July 16, 2021, 05:40:41 AM
Can you post some photos of the HP jack?  Typically either the wires are loose and not well connected or they are fine, but if you apply too much heat to that jack it will deform and stop working properly. 

With the phone, it's not that the noise is traveling through wires into your amp, but through the air. 

I still do believe you are picking up some wireless interference.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline pofofo

  • Jr. Member
  • **
    • Posts: 42
Reply #18 on: July 16, 2021, 05:50:09 AM
Here, hope this covers it.

I read some in the crack part of the forum about crackling and popping and I guess I should try another resolder. Better get som lead solder first.



Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19694
Reply #19 on: July 16, 2021, 06:23:59 AM
Yeah, I would get some 60/40 solder.  When I get repairs in that have been built with lead free solder, I will go through the build and add a little leaded solder to every single joint before I even start debugging what's going on.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline pofofo

  • Jr. Member
  • **
    • Posts: 42
Reply #20 on: July 16, 2021, 11:21:06 AM
Thanks for the info. I ordered some leaded solder and will reflow.



Offline pofofo

  • Jr. Member
  • **
    • Posts: 42
Reply #21 on: July 17, 2021, 09:40:41 AM
Yup, you were correct. Its the 4G mobile internet thats causing it. Thank you for your help and patience.

Now, is there anything I can do to avoid the problem (other than not using my phone that is)?



Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19694
Reply #22 on: July 17, 2021, 10:00:05 AM
Distance should help a whole lot, but some phones are just really noisy.  It's possible that some aluminum foil wrapped around the tubes and touching the chassis might help. 

If you use airplane mode and have a wifi connection, that should resolve the issue and leave your phone fully functional too.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline pofofo

  • Jr. Member
  • **
    • Posts: 42
Reply #23 on: July 17, 2021, 08:27:40 PM
With the phone hooked up to the amplifier, I heard the noise while turning on/off airplane mode.

Then I had the airplane mode off and turned off/on: wifi, bluetooth and 4G separate the noise did not appear (I was trying to pinpoint exactly what was making the noise). The noise only appeared when I turned airplane mode off/on.

With my laptop hooked up (and streaming via wifi) there where no noise, so it seems the phone needs to be hooked up to the amp for the noise to be heard.


I don´t know if it matters, but my phone is a Samsung s10e from 2019.