Electrical question

OK you geniuses. I posted this in the middle of another thread but not many are going to see it.

I don’t want to buy something and have it not work. So it’s about daisy chaining pedals to a power supply. You might have seen those cables that you can share up to 5 pedals to one outlet. Say you have a 9v outlet at 300 mV. You put 5 pedals on it that each require 100 mV, but each would get only 60 mV. So, it shouldn’t work. But you really would only have let’s say 2 pedals on at once, so they could both get up to 150 mV, correct? So if your not running them all at the same time, no problem?

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If you’re not running them all at the same time there should be no problem, however if you do and depending on the design of the AC adapter it may overheat or die on you.


edit:
“there should be no problem” has a catch. Check the below post


I don’t recommend daisy chaining at all. The amount of noise it brings into play is just not worth it.

I advise you into considering a dedicated power supply with isolated outputs.

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Yeah, I would not daisy chain if I didn’t have to, and I can’t see a reason for that. I posted a good option for inexpensive power supply in that other thread that I got and am happy with.

Well, here it is again in case you did not see it there.

Is there a reason you WANT to daisy chain? Is it because you already have it? Or because it cost less? In the end it could cost more I think if you ended up messing something up due to overload.

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Soo the long story is this. I bought a whole shit ton of pedals. I had the small strymon Ojai, 5 outlets, not enough. I bought some voodoo labs splitter cables so problem temporarily solved. Then I bought a pedal that needs 18v. So I decided to get an mxr with an 18v outlet. I thought I clicked on the mxr 10 outlet one, but by accident clicked on another 5 outlet mxr. So not a problem, I still have the existing voodoo splitters. Except my zoom pedal takes 500 mA and the mxr is 300 mA. So I can use two outlets for it and a power doubler cable, but then I have only 2 open outlets. Soo I could daisy chain off them and then AARRGGH ARE YOU FUCKING KIDDING ME!!!

I also have a cheap Donner power supply that has been 2 months in the mail coming from Bulgaria that also won’t work. I’m serious.

So I will be selling 40 power supplies and 200 cables. And buying the correct mxr. Actually I will take a chance on the one you suggested. It’s not isolated but I don’t think that matters much in the real world. And it’s Amazon so you can always return it.

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LOL man that’s awful. Good luck with the new order.

I was looking at the MXR as an eventual upgrade. Still haven’t had any cross-pedal noise with the cheapo yet though.

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It gets noisy

Safety net :wink:

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I have not experienced this. But I have a gate on a few pedals, which has worked great, and has not sucked out any volume. I could see if all the pedals did not have a gate in them, where it could get noisy, but you still get that with many of the high gain pedals anyway, IME.

I have also considered getting a noise suppressor pedal. Not a typical gate that you put in front of your chain, but the ones that actually loop your chain thru.

Since using the gate on each pedal, it has not been much problem however, it is pretty silent.

And, as I said in the beginning, with this power supply, I have not gotten anything more then Compressor and Fuzz / OD / Distortion pedals typically give out.
This is what I have experienced, so there could be more to what you are saying that I don’t know about.

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But your power supply has isolated outputs, right?

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It says it does, but I have been told by @howard it’s not really isolated, it is rigged to be sort of.

Plus, I think he was talking about this power supply, the one I have, that you were replying to.
Because he was saying he can return it to amazon.

Think he says it’s not isolated because it was explained that the cheap ones, take short cuts so they can say they are isolated when they really are not.

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What I said was:

  • I know my Donner isn’t isolated (despite claiming to be) because have seen a teardown and all looked like they were are on the same bus.
  • I have read that the Calines and Donners use the same circuits (though I have not verified this).

That said, I haven’t had a noise issue on mine either.

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Yes, I was not trying to quote you word for word, rather trying to get the idea of what you said, cuz I am weak with electrical engineering and design, I am more in mechanical engineering and manufacturing, so I don’t know how to word it correctly and just have to state “ I have been told they were not”. In the most general way.

But I think you said in one post, and I can’t quote it, cuz I don’t know enuf about it, that they are on the same bus, but they shield them? Or do something so they can get away with calling them isolated.

Yours might be! But at that price it’s not clear :slight_smile:

You should be able to check. My understanding is that an isolated output power supply should provide each of its outputs with a dedicated power source that is not connected in a bus with the others. So you should be able to take a meter and see if there’s an electrical connection between the power outputs. My understanding is that for an isolated supply there shouldn’t be. I could be wrong though.

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Yeah, in the teardown of mine you could see it looked like the power was coming from the same bus but each jack had a choke coil on it, presumably to block noise from coming back and forth between the power/ground connections.

Seems to work ok for me. Plus, cheap :slight_smile:

That’s the part I couldn’t reproduce in my posts.

I don’t have access to a meter, and it’s not really important enuf for me to open it up and look, but my guess is that the choke coil is probably being used in the Caline as well.

The important thing, in your and my cases both, is that there is no considerable amount of noise.

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I own a non-isolated power supply (Harley Benton PowerPlant) and compared to having the bass directly connected to the amp there’s a distinct hum present. Depending on the pedals I have connected, the hum gets significantly louder and more annoying.

I noticed the reverb and delay pedals create the worst hum. Also tried to solve this with a noise gate, but in some configurations, the threshold I have to have it cuts away too much.

I have the idea that having the pedals connected through the fx loop will reduce the amount of hum, but haven’t tried yet because I’m lacking enough cables.

In any case I have another power supply on its way, this one has isolated outputs, and more cables. I will try the fx loop thing with both power supplies and will post my observations.

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Was the HB sold to you as non isolated, or isolated?

I think the noise suppressor that loops thru the pedal is better since it is not just a choke in front of the pedals, but, I think, clips them after they are all connected, or both before and after, and in doing so, is able to do it with less clipping.

Clipping might be the wrong word here, Gate or gating May be more accurate, or a better way to say this.

I don’t have actual experience with either, I only know from research and YT demos and vids. I use hates in some of the pedals that have it, and it helps a lot,
But
The hum, or noise, is not there Until the pedal is activated, without the gate, then if I turn the gate on, it goes away. Turn the pedal off, and there is no hum or noise, so I am not getting it from the P/S, so in this case, the gate is only needed for the pedal(s), and not for the P/S

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Non isolated. I didn’t knew better back then and went for the cheapest(*) one with the best reviews. In any case it was a good upgrade from the daisy chain and I will choose a non-isolated power supply over daisy chain any day of the week.

(*) There’s a portuguese saying which is so true in my case: “O barato sai caro” - “What’s cheap gets expensive” (rough translation)

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So true in so many cases.

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