Home Forums Help/Technical Questions Noisy Tube EQ pedal fixed

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  • #78389
    Lee Moder
    Member

    How I fixed my noisy Tube EQ pedal:

    Background:

    I recently purchased a Tube EQ pedal online. The pedal arrived and worked fine but the next day it was completely dead. I contacted the company I bought it from and they told me it would be a faulty power supply. They sent me another one and sure enough the pedal worked again.

    I bought the pedal for use in my home studio. When I started recording with it I noticed a buzzing noise on every track I recorded using the Tube EQ pedal.

    I tried moving the pedal around my room to see if anything was causing interference. I searched the net and found suggestions to tighten the screw between the tubes. I replaced the tubes with TungSol ECC83’s (which gave the pedal a nicer sound). None of these got rid of the buzzing noise.

    I resigned myself to the fact that I had wasted £130 on a pedal that I would not be able to use for recording. A shame as I really liked what the pedal did to my guitar sound. I put off my plans to buy a Black Finger pedal as I was sure this would have the same noise problems.

    To make matters worse the pedal would lose power whenever I pressed the bypass switch! I know nothing about electronics but assumed this could be a loose connection inside the pedal. So I decided to open it up.

    How I fixed the buzzing noise:

    I removed the 4 screws on the top of the pedal case (leave the one between the tubes) and removed the black base cover from the pedal.

    Inside the pedal I noticed that the two connections for the power supply were nearly touching. They were about 1mm apart.

    Whenever I pressed the bypass switch the power cable, which is quite a loose fit, would move slightly and cause the two connectors to touch shorting the power to the pedal. This is probably what caused the first PSU to die.

    I bent the connectors apart so they could not touch and this fixed the power loss problem.

    It was when I had the cover off that I noticed the buzzing noise from the pedal had stopped. If I moved the base cover towards the top of the pedal the buzz noise came back.

    The PSU socket is attached to the base of the case. I removed the socket from the base. The closer the PSU socket is to the centre of the circuit board on the pedal, the louder the buzzing noise!

    I now have the PSU socket and wire sticking out of the bottom of the case and the buzzing noise has completely gone.

    I know this is not an ideal solution but I don’t gig with the pedal so hopefully I won’t damage the wires.

    The pedal works great, I really love the sound and no buzzing noise!

    I took some pictures to show what I have done to the pedal.

    http://www.flickr.com/photos/39318658@N07/3616532996/

    I hope this can help other people who may be frustrated with their noisy pedal. It takes less than 5 minutes to do.

    Please let me know if you need a better explanation and if it fixed your pedal!

    #97717
    The EH Man
    Moderator

    Way to go with finding a solution to your problem. Too many people come here w/o even first trying for themselves to fix the problem.

    The problem is likely due to the AC voltage that is supplied to the pedal by the adapter. Perhaps a small grounded shield around the PSU entry would help alleviate the problem.

    #97720
    Lee Moder
    Member

    Hi Ron,

    Thanks for the reply and suggestion.

    Please help as I know very little about electronics.
    What could I use as a shield and how would I ground it?

    Best Regards,

    Lee

    #97722
    The EH Man
    Moderator
    Quote:
    Hi Ron,

    Thanks for the reply and suggestion.

    Please help as I know very little about electronics.
    What could I use as a shield and how would I ground it?

    Best Regards,

    Lee

    Just a small sheet of metal attached to the chassis between the circuit board and the PSU socket.

    #97725
    B.Daws
    Participant

    Lee,

    If you are going to hang it out of the case like that, you should just go ahead and hard wire the power supply and put electrical tape over it! In fact, I might do this with all my tube pedals as well as I know my Muff’n and my Hot Tubes both buzz pretty bad. If you don’t know how to hard wire I will do one of mine and post some pics in a few days! Take it easy and keep rockin!

    #97727
    Lee Moder
    Member

    Thanks for your help Ron. I will try a ground shield and see if that works.

    Dawson, I would be interested to know if hard wiring works with your pedals and gets rid of the noise, let me know how it goes.

    Best regards,

    Lee

    #97816
    Gando
    Member

    Good job, Lee, and thanks for posting. I have an LPB 2ube unit with the same sort of twin tube layout that is noisier than I would like (although not nearly as glitchy as yours). I will look into the power jack integrity and placement to see if maybe I can quiet it down some. Thanks for for sharing your experience & your fix.

    #97827
    Lee Moder
    Member

    Hi Gando! Thanks for your reply.

    Hopefully this will work with your pedal as well.

    I have been using mine again tonight and it really is a great pedal now the buzzing has gone.

    Please post back and let me know if it fixes the noise with your pedal. It will be interesting to know how many of the different pedals this works with.

    Best regards,

    Lee

    #117116

    I had the same problem with my new EHX Tube EQ. I searched the web and found this page, with the solution to remove to 12V jack from the pedal housing, to put it out of the housing, and the noise is gone. Worked perfect with mine, too. But as I use it for gigs I did not wanna have the wires stick out of the pedal.

    So I found out that there is an easier way to get rid of the hiss/hum:

    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:)

    #117408
    stimresp
    Member
    Quote:
    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.

    Hi, this is good information and I would like to try it, but a little worried about frying the device (or myself) as I’m no expert. Could you post a picture or diagram of the connection points? It would really help a lot and be hugely appreciated.

    Thanks in advance :)

    #117409

    I am not an expert, too. No connection points there. Loosen the 4 screws on the top, you can remove the upper part then. Be careful, the upper part is still connected with the bottom part, through the power supply wires. Now get some aluminium foil and cut a stripe of 3-4 layers, that has the same height as the pedal. Wrap another layer of paper around the aluminium foil to make sure that it does not conduct anything by accident. Maybe leave a small slint in the paper, fotr the power supply wires tp got through, or place them under the paper. Just place the paper-aluminium-stripe behind the power supply connection. No diagram or wiring here. I will see if I can post a photo of it soon. Just try it, and listen. Just add foil, leave everything else as it is. Listen to you amp, and if the noise is gone, it was right:)

    “Perhaps a small grounded shield around the PSU entry would help alleviate the problem.” – Thats absolutely it.

    #117426
    stimresp
    Member

    Hi, well I opened it up and, after looking closely at the situation, I decided to copy the OP and take the power socket outside the box. The advantage is that this gives me more room on the pedal board – the side-position of the socket is a bit silly.

    I must say that, noise-wise, the difference is night and day. The noticeable residual noise has completely disappeared.

    Thanks for the tips. Can’t believe EHX let them leave the factory with this easily-fixed issue. Very nice pedal :)

    #120422

    Can someone post a picture of how to position the aluminum paper shielding

    #120579
    Junagu
    Member

    Yeah a diagram would be great! Going to try it anyway though on my Black Finger.

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