Metalic ringing from front tube (5963 stock)

[l33tsauce7]

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

[Paul Birkeland]

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. 

[l33tsauce7]

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.

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

[Paul Birkeland]

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.

[Larpy]

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

[l33tsauce7]

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.

are those all the same tube or just a random assortment? thats pretty cheap!

[l33tsauce7]

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

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]

The second group is a smattering of different 12AU7s made by various companies.

[l33tsauce7]

The second group is a smattering of different 12AU7s made by various companies.

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.

[Paul Birkeland]

That's an inexpensive way to get into tube rolling.

[Mucker]

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.

[l33tsauce7]

That's an inexpensive way to get into tube rolling.

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!

[Paul Birkeland]

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.

[Deluk]

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.