Popping when inserting headphone jack

RestoredSparda · 2004

0 Members and 2 Guests are viewing this topic.

Offline RestoredSparda

  • Full Member
  • ***
    • Posts: 84
on: July 26, 2023, 09:39:57 AM
Finished a new build. Double checked and reordered all points going to the headphone jack as I've had this popping issue before.

I'm getting a mild popping in headphones when the middle and last ring on the TRS jack make connection and am inserting the headphone jack while the amp is on.

The mild popping occurs when removing the jack and inserting while amp is on. The popping volume is louder if volume isn't set to minimum.

My question. After going over this amp with a fine tooth comb, is some mild popping when inserting a headphone jack normal for the Crack circuit, or do I need to do some more troubleshooting?

No.other issues, all resistance and voltages passed. No noise when tapping on chassis while headphone is plugged in and Amp is on.  No noise when headphone is connevted and amp is turned off.  Normal startup noise when Amp is turned on. Etc.

Thanks for the help!
« Last Edit: July 26, 2023, 11:25:42 AM by RestoredSparda »



Offline Doc B.

  • Administrator
  • Hero Member
  • *****
    • Posts: 9641
    • Bottlehead
Reply #1 on: July 26, 2023, 02:16:48 PM
Reflow all of the terminals on the headphone jack and see if that helps.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline RestoredSparda

  • Full Member
  • ***
    • Posts: 84
Reply #2 on: July 27, 2023, 05:34:00 AM
Thanks. No change after resoldering.

I also inserted an adapter 1/4 inch to 3.5mm, so I could rule out moving joints as the culprit (I think). With the adapter. I still get mild pops in headphone when inserting the 3.5mm end into the 1/4 adapter. 




Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19694
Reply #3 on: July 27, 2023, 05:39:04 AM
99% of the time this happens because one of the black wires that connects to the headphone jack is not captured by solder.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline RestoredSparda

  • Full Member
  • ***
    • Posts: 84
Reply #4 on: July 27, 2023, 06:26:17 AM
Thanks Paul. I went over the entire build step by step and everything looks correct and solid.

I am going to pull out the headphone jack completely and rewire with a spare. Can't think of anything else to mess with.



Offline RestoredSparda

  • Full Member
  • ***
    • Posts: 84
Reply #5 on: July 27, 2023, 06:53:05 AM
Thanks for keeping me on track guys. I reflowed all the headphone jack terminals for the 3rd time this time at a higher heat and really let em get hot.

I also at the same time removed the aftermarket output caps and reverted to stock. 

Pops are gone. Time to see if the caps were the issue and put them back.  Thanks again for steering me to the correct path.



Offline RestoredSparda

  • Full Member
  • ***
    • Posts: 84
Reply #6 on: July 27, 2023, 09:01:20 AM
Turns out to be the Russian output caps. After reinstalling the mild pops are back. Perhaps the higher voltage rating or they are just bad? Very old caps. Anyways the mystery is solved.
« Last Edit: July 27, 2023, 09:13:32 AM by RestoredSparda »