Having (grounding? cable?) problems w/ pedalboard; super loud 30Hz square wave comes out of nowhere

Discussion in 'Effects [BG]' started by Invisible_Kid, Oct 12, 2018.

  1. Invisible_Kid

    Invisible_Kid Guest

    Jun 1, 2010
    Hey y'all,

    I'm having this problem that's baffling me: something in my signal chain, whether it's a patch cable, a power cable, a pedal, or some mix of the three, is making an extremely loud 30Hz square wave under two different and seemingly unrelated circumstances. Do any of y'all know what could be causing this?

    The awful sound

    It's an imperfect 30Hz (and sometimes ~31Hz, as can be heard in the recording) square wave and it looks like this:


    Here's a direct-in clip of the wave in question, downloading should be enabled if y'all need it (LOUD):

    The setup

    My setup for context, with numbers for pedal order in the signal chain. The relevant pedals are 4, 4-1, and 4-2. 4-1 and 4-2 are in the effects loop of 4:


    4 is a Simple Switch Momentary True Bypass Looper, except I got it with a latching switch instead. I got it to keep the Bass Whammy (4-1) and Pitchfork (4-2) in their own little loop, for some practical reasons I won't dive into.

    (In case it's relevant, I'm using a One Spot with two of those Multi Plug 5 cables for power for everything except the Bass Whammy; for that, I use the included power supply. I'm using BOSS BIC-PC 1' patch cables between 1 and 2, 3 and 4, 4 and 5, & 4-1 and 4-2; MXR DCP 6" patch cables between 2 and 3 & 5 and 6; DiMarzio Neon Overbraid Jumper 6" Cables between 6 and 7 & 7 and 8; and George L's 1' cables between 4 and 4-1 & 4-2 and 4.)

    The circumstances

    It could be important to note that the noise only started happening today, when I hooked up my newest pedal, the Simple Switch (4), with my new George L's patch cables--these cables are what I'm using for the Send and Return on 4. The last time I tested the setup was at practice one week ago, where the signal chain went 3, 1, 2, 4-1, 4-2, 5, 6, 7, 8, and I had no problems.

    This awful noise happens when...
    1. I enable the Simple Switch (4) and then either switch on 4-1 or 4-2. In this setup, the noise happens if and only if 4-1 or 4-2 are turned on.
    2. I have a setup in which 4 isn't even in the signal chain, but where 3 goes into 4-1 goes into 4-2 goes into 5, AND at least one of the connections between these four pedals is made with one of those braided BOSS patch cables--you can see one connecting 4-1 and 4-2 in the picture. None of the pedals have to be switched on in order for this to happen.
    You might think this could mean it's a problem with those BOSS cables--I sure did--which makes sense until you learn that the noise DOESN'T happen when...
    1. Any one of the seemingly problematic cables are used to connect the bass directly into the amp.
    The plea for help

    I can usually figure these things out on my own, but I'm completely stumped. Could it have anything to do with the fact that the Pitchfork (4-2) uses buffered bypass but all the other pedals are true? Can patch cables work totally differently alone vs. in a chain? Is it a power thing, from the LED in the Simple Switch (4)? Is there some strange patch cable requirement I'm not aware of for these pedals, or something obvious I'm totally missing? I don't know, y'all. I've never had a noise like this come out of any of my equipment in the decade I've been playing. All I know is I'm very frustrated, and if you need any more information or a video demonstrating these things happening, just let me know. Pretty please, can anyone help? :help::help::help:

    Thank you so much for reading!! <3
  2. Correlli


    Apr 2, 2004
    Wellington, NZ
  3. Snaxster


    Nov 29, 2008
    Hello. I agree with Correlli's suggestion of process of elimination. And I would start with the most likely suspects: the new pedal and patch cables. My intuition is that the new pedal is problematic in context.

    Narrow the context by first replacing the new patch cables with ones that you knew to be good. If the problem persists, remove the new pedal. If the problem persists, then it was neither of those as sole causes, though they might still be contributors to the cause in the larger context, particularly when used there together.

    Also, please do yourself a favor and get a proper power supply. :) My standard for some years is the Voodoo Lab Pedal Power ISO-5, but anything in that class will do. A more sophisticated power supply than what you're using now, especially one that features isolation, will automatically reduce the number of possible causes of such noise problems.

    Good Luck!
    biguglyman and Fuzzbass like this.
  4. Invisible_Kid

    Invisible_Kid Guest

    Jun 1, 2010
    Thank y'all for the suggestions!! I'm gonna give this a shot and see what happens.
  5. Remove everything.
    Start with only the bass to the amp.
    Check for any sign of the problem.

    Add back in one pedal at a time.
    Listen for any sign of the problem with each added device.

    If it only happens, or starts happening with a specific device note which one.
    If it starts before adding the last device and gets worse as you add, note the first device and each one added.
    Continue until everything is hooked up.

    Now, start eliminating devices one at a time starting with the first one you put in and working to the last one.
    Note the last device that was in line before the problem stopped.
    Or if it just s starts to improve note the last device you removed before the improvement.

    Make notes of all of this.

    What I’d be looking for in doing this orderly process of elimination is that the power supply that runs everything is not up to the task of running everything.

    Another thing is that something else in the room is making noise and it’s getting picked up in your board.
    30-ish Hz is the frequency you get from a half wave rectifier circuit. Those are the cheapest to build and used in things that don’t normally require very clean DC voltage to operate. If a filter cap goes bad on the offending device, with a half wave supply, you get 30-ish Hz. It could be almost anything in the room or the house or the circuit you gear is plugged into. Rule nothing out. Furnace, aquarium heaters, fluorescent lights. Computer monitors. Anything that runs on electricity.
  6. Invisible_Kid

    Invisible_Kid Guest

    Jun 1, 2010
    Hey all, after extensive trials and note-taking using the process of elimination that y'all suggested, I've discovered that the problem is the Simple Switch (4). I'm thinking about just getting a Saturnworks instead.

    Also, this thread is probably the impetus I needed to go out and buy a big kid power supply. Many thanks for the input!!
    Fuzzbass likes this.
  7. FilterFunk

    FilterFunk Everything is on the ONE! Supporting Member

    Mar 31, 2010
    Keep the sound file, because that's a killer synth tone sample!:D
  8. megafiddle


    May 25, 2011
    Half wave supply noise is still 60 Hz.

    Consider that full wave is 120 Hz.

  9. Yep! You’re right.
    Half the waveform is gone, but still 60 Hz.
    Thanks for the correction.
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