Metalic ringing from front tube (5963 stock)

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l33tsauce7

New member
As the title states, anytime i bump the desk, type or touch the headphone jack/tube it sounds like i can hear the metal from the plate amplified (go figure) through my headphones. It is a fresh build and passed all tests with no issues and actually sounds amazing aside from this hiccup. Using DT1990s and have tested 3 different cables all do the same thing. Fiddling with the jack on the cans themselves does not reproduce the sound. Less of an issue but ive also noticed a very minor oscillating hiss or quiet static when there is no audio being played. It seems to happen in roughly 5 second intervals. Im open to any and all advice! If you need anymore info just let me know and ill do my best to answer in a less than ignorant way hah. Thanks in advance
 

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The noise you're hearing at 5 second intervals would most likely be interference from a wireless device that's close by (your phone can even do this).

What you're describing is a microphonic tube, and there's no harm in continuing to use that tube. 
 
Paul Birkeland said:
The noise you're hearing at 5 second intervals would most likely be interference from a wireless device that's close by (your phone can even do this).

What you're describing is a microphonic tube, and there's no harm in continuing to use that tube.
Click to expand...



so the interference was fixed when i moved the amp (good call you are right). i realized it was on the same level as my router just on the other side of the wall so that has been fixed. however the ringing is a bit annoying as i move my head while im working and typing is audible through vibrations basically. this is my first tube amp so i dont really know whats normal and what isnt. I wouldnt think movements and MINOR vibrations would affect it much
 
A little bit of microphonics isn't abnormal, but if it's annoying you could just buy an inexpensive replacement tube.

https://www.ebay.com/itm/304690491001?hash=item46f0f7ee79%3Ag%3A19cAAOSw-UBjQjAb&amdata=enc%3AAQAHAAAAkNfkhglG4n%2BlLmTBibw5%2B%2FGR2v4BaPohrPlELcrg8byuY%2BMGgwHwxNPbwBLKlK%2FA4s8kGqMoO2kt7DyNbJIVmtn6RsUgAmK9BuAi33zXtSuTSkIK3FwMPoqdVbwA4mwSUItUsgkdzIJNQmlEk1nMrQv5Yy4ARL28pLxbJkRp%2Bcoou%2Fd9dcTIlz%2FaGr3oRPXL0w%3D%3D%7Ctkp%3ABk9SR4KFzMyNYQ&LH_ItemCondition=3000

Something like that (which appears to be 6 tubes?) would be worth snagging.

https://www.ebay.com/itm/134322754279?hash=item1f464292e7%3Ag%3AyPIAAOSwu8FjbXpO&amdata=enc%3AAQAHAAAAkM2Z4vPJ0SxcZuFsGjgbZHkiC73U%2F5fqMuKo4%2Bqj37xQy5KYMkq7zAIv9%2FBSXkrt6hG%2FJdNM3wE7yGexoePq%2FOXz%2Flg4efhUE3Q5geetgE1P1MALCys3O4eeao%2FPjWbEh9HPyNuamUbQg1DiaOuZDmZHFWG40VjrNnFOWDtlBiuVWNsALBqh9T6K7qfCybXtAQ%3D%3D%7Ctkp%3ABk9SR4aFzMyNYQ&LH_ItemCondition=3000

A group like that would give you lots of choices to listen to.
 
You can also try placing a silicone ring or two around a microphonic tube to dampen vibrations.  They don't always work, but they're cheap to try:

https://www.tubesandmore.com/products/damper-rings-high-temperature-silicone-red
 
Paul Birkeland said:
A little bit of microphonics isn't abnormal, but if it's annoying you could just buy an inexpensive replacement tube.


Something like that (which appears to be 6 tubes?) would be worth snagging.


A group like that would give you lots of choices to listen to.
Click to expand...

are those all the same tube or just a random assortment? thats pretty cheap!
 
Larpy said:
You can also try placing a silicone ring or two around a microphonic tube to dampen vibrations.  They don't always work, but they're cheap to try:

https://www.tubesandmore.com/products/damper-rings-high-temperature-silicone-red
Click to expand...

ah that would be a cheap fix. i had actually thought about putting a rubber grommet of sorts around the base of the socket where it attaches to the metal plate but its nice to see this isnt just a ME problem hah
 
Paul Birkeland said:
The second group is a smattering of different 12AU7s made by various companies.
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gotcha, so the idea here is to just tube roll and maybe find a tube that doesnt have as bad of microphonics? im not apposed to this idea as i wanted to tube roll eventually anyway just want to make sure i understand correct. microphonics is a natural thing and i did not goof on my build somewhere, and can be combated through dampeners and tube rolling.
 
My tube gear doesn't care for the 2.4GHz band in my home. Luckily nearly all of my wireless devices are 5GHz capable. I can turn the 2.4 band off and on in my router and the issue with 2.4 is obvious so I don't use it anymore. The 5GHz band is quiet while the 2.4 produces a fuzzy morse code pulsing sound and very slight squeal.
 
Paul Birkeland said:
That's an inexpensive way to get into tube rolling.
Click to expand...

ok last two questions for now lol. ive noticed my dt1990s are a bit sensitive to the volume and i only need it at maybe 15 to 20% before its too loud. Is that resistor trick on the forums for the pot a proven/safe option? And before i dive into the rabbit hole of reading and buying tubes for myself, which tube is more impactful for rolling? power or pre

thanks for all the input!
 
Yes, the resistor mod for the volume pot what you'd need to do in that situation.

The 12AU7 is going to have a pretty large impact on how the amp sounds, though a really fresh vs. really dead 6080 will also be very audible.
 
https://forum.bottlehead.com/index.php?topic=11676.0

This mod can sometimes work magic on random noises. Worth fitting but may not work in your case.
 
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