I would not open it as its very easy to short out the high voltage capacitors and kill the unit.
I would contact service at info@ehx.com
First remove it from the chain and go straight into the amp to make sure its the unit.
ALSO make sure the tube eq is plugged into the same ac outlet the amp is.
It could be a ground loop.

info at ehx dot com
Hope that helps.
Not sure why I can not post a link to our own company!!!!!!!!!!

Hi!

Did you manage to resolve the issue? Thanks in advance!!

Thanks for the reply, and the context is always necessary!

I don t have the tubeEQ, but I have the wiggler which is a very similar design and I am facing similar issues.

In my case, things improved a lot when I tightened all the screws, especially the middle one in between the two tubes. Try untightening the screws before tightening because metal oxide can form there and it inhibits good contact between parts. I also removed the washers from the knobs, mine had gotten a bit corroded and i think it improved the buzzing a bit.

I am going to replace some cables inside with shielded ones and I ll report if that makes a difference (although i don t have enough time until the end of August)

I absolutely LOVE the wiggler and what it does to my sound, it s a shame that there is this noise because it’s one of a kind. I wanted to buy the black finger as well but first I have to see if there is a solution.

Again, the most important tip is the middle screw!

My tube EQ also has ground loop hum like low frequency noise from the beginning & it’s so obvious. While guitar sound is sustaining, may be no noise or I can’t feel the noise but as soon as guitar sound stop, the noise coming out. It’s from Frequency knob. Noise going to be almost unnoticeable if I turned the knob more than 12 noon. Noise get so obvious as I turn the Frequency knob to before noon (sound gets bassy). No noise at all when it’s bypassed. I use same AC power source for my mixer, amp & this tube EQ.

Live music with noisy venues may be OK but I can’t use this device for professional recording studio or Theater music in the pit situation which often require us to be dead quiet while actors playing without music.

I like this EQ but it’s yet consumer product level, not a professional one.

---

P.S.:
I found a following trick & noise problem got much better after a few try, but still silent hum noise exist though.

< The problem is, that the tubes are not shielded against the electromagnetic interference of the tubes.
So I opened the pedal, took a piece of self adhesive aluminium foil, and placed it between the power supply jack and the tubes. Make sure that the foil is not touching the wires so it can’t conduct (use another layer of paper, to be sure). And that’s it, all noise is gone.

As this hiss/hum seems to be a general issue with the Tube EQ, I can’t understand how EHX does not fix this bug in future pedals.

Now I am totally happy with my Tube EQ, no noise/his/hum anymore. It’s an amazing pedal that does sooooo much to your guitar’s tone. I never expected that would make such a big difference.

Hope that helps:)