Problems with hum in my board

Problems with hum

First of all: let’s make something VERY clear – I’m no technician … I don’t know much about what’s going on inside my amps, pedals and stuff. I’m a pro guitar player who is really serious about how my set-up sounds. And even though I have many years experience with this, I still get surprised. Here are some experiences that might save you some problems with hum.

I’ve written about my pedals, boards and my power supplies. I’ve also written about my many learning experiences from setting everything up correctly, so it should be quite easy to make everything work.

I was ready to mount everything to my board. I will describe all my pedals as average or above. The power supply – the Ciokolate is awesome. I had the order of the pedals and had decided what outputs I should use on the Ciokolate. The pedals got the right voltage and the right current. I used the right cables so the polarity was ok and they all were on an isolated outputs. It should be working – and it did!!

But I noticed some seriously hum from my Plexi Drive deluxe.

Some of the pedals in my board … I love the sound of my Plexi and Euphoria – awesome pedals 🙂

To make it more weird only from the Post gain circuit?! First I tried to swap power outputs with some of the other pedals, but the problem stayed to the Plexi. Some friends came with suggestions to narrow down the problem. For instance by trying the pedal all by itself with a battery and in the board with a battery. Good tips! And actually I realized there was something wrong with that pedal. Without problems did I get another one, that worked better, and didn’t have some other issues I had experienced with that specific pedal. But still I got some  serious “normal” gain hum.

And even weirder

The hum disappeared when I touched the switch on the pedal and the switch on any other pedal, that didn’t have True Bypass.

One of the many tips that I got from enthusiastic friends on FB was to check if everything was grounded properbly. Shouldn’t be an issue, since everything in my studio is grounded. All wall-sockets have earth/ground here. BUT I realized that I in my hurries while I was putting everything together, I had taken a regular Danish extension chord with no grounding. In Denmark you’ll only have your sockets grounded in your kitchen and bathroom. The regular sockets in your living room, won’t be grounded. Therefore regular extension chords don’t have grounding.

First I swapped so my board was connected to an extension chord with earth, sitting in my 19″ rack, but the hum stayed. Actually quite obviously, since that extension chord in the rack expected a third leg in the plug to use the earth/grounding. The plug on the Power supply had the grounding on the sides, no extra leg and so did my amp. The moment I connected the power supply directly into the wall socket and did the same with my amp – all hum disappeared. So that was one way to avoid that hum.

Unfortunately I can’t expect every wall socket to be grounded – at least not in Denmark. And the fact that I could manually remove the hum by touching the switch and a jack annoyed me.

More problems with hum

Even though I’ve been playing guitars for years, and still practice a lot, I prefer to use both my hands on the guitar – not have on of them occupied touching my overdrive while soloing.

A fast and cheap way to get rid of problems with hum
Wampler Plexi Drive Deluxe in my 2016 board, with the wire that removed the hum

So the fast and easy way to fix this – plain wire. I took a little bit of wire, wrapped it around the jack, and wrapped the other end around one of the the potmeters on the overdrive – and everything was silent … really silent – no matter if I have a grounded power cable or not. I called a friend of mine, who normally fixes my gear to make sure I didn’t harm anything by doing this. Everything should be cool. Ok, it doesn’t look better with that piece of wire, but it’s a fast, cheap and an effective way to get rid of hum … that hum, oh that hum.

Hope you can use this little experience to avoid similar problems. If you want to read more about my pedalboard, the setup, and the pedals I use – you can read it here – Have a great day.

2 Replies to “Problems with hum in my board”

  1. Hello friend, I have this same problem, the strange thing is that with other pedals I do not have a hum, but with this plexi that I bought new recently, the hum was very loud, a question …….. I am using a source 9v. or is an 18v necessary?

    1. Thanks for sharing – and sad with the hum issue 🙁
      I think it works fine with both … normally I prefer running my pedals with the highest possible voltage recommented – give more headroom and clarity … but it’s a matter of taste and sound ideals.

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