any suggetions?

[daz]

I''m redoing a small pedalboard that will have 3 pedals powered by one wart that has plenty of current for the job. But i'm wondering if there are better ways to do it to assure low noise or other unwanted interaction. Like maybe just splitting the + up 3 ways going to each pedal but just one - lead attached to the signal ground. Any suggestions as to the best way to go ?

[Mick Bailey]

I have a Marshall 2203 full stack in right now that gets played with the gain on 8 and turned up to deafening levels. It's highly sensitive to any kind of noise and has three pedals running daisy-chained off a cheap Chinese SMPS supply. It's a noisy setup and my gut feeling was that the supply wasn't up to it and was bound to be causing additional noise. So I subbed in a brand-new One-Spot Pro CS7 and connected each pedal individually to a single isolated output with short leads and no daisy chain.

Zero difference. No detectable change in hum or anything else. There's a slight bleed from a Chorus pedal oscillator when in bypass mode that's there with both supplies. I also tried my bench supply with the same results.

The lesson from this is that something that may be perceived as a problem in reality may not be an issue at all. You (and I) may be wanting to fix something that is just fine like it is.

[olddawg]

I have a Marshall 2203 full stack in right now that gets played with the gain on 8 and turned up to deafening levels. It's highly sensitive to any kind of noise and has three pedals running daisy-chained off a cheap Chinese SMPS supply. It's a noisy setup and my gut feeling was that the supply wasn't up to it and was bound to be causing additional noise. So I subbed in a brand-new One-Spot Pro CS7 and connected each pedal individually to a single isolated output with short leads and no daisy chain.

Zero difference. No detectable change in hum or anything else. There's a slight bleed from a Chorus pedal oscillator when in bypass mode that's there with both supplies. I also tried my bench supply with the same results.

The lesson from this is that something that may be perceived as a problem in reality may not be an issue at all. You (and I) may be wanting to fix something that is just fine like it is.

Have you tried using batteries in the pedals? My pedal board is a bit noisy and I use a OneSpot. In studio I pull what pedals I'm using off the board and use batteries.

[The Dude]

If nothing else, a quick test with batteries would tell you if it's the power supply causing problems.

[daz]

If nothing else, a quick test with batteries would tell you if it's the power supply causing problems.

I haven't even begun to put it together yet, thats why i'm asking....so i can avoid a lot of time spent wring a power rail that might cause issues.

By the way, what does a one spot have over a normal wall wart besides the obvious wiring options and plenty of current?

[The Dude]

I can't speak to the One-Spot specifically because I haven't been inside one. Typically, however, in this type of pedal power thingy, each jack has it's own separate supply starting at the front end with a multi-tap transformer that supplies several rectifier circuits. Each rectifier powers a corresponding output jack. So, each supply is independent of the other for isolation. I've worked on other brands that are like this. Off hand, I remember a Furman unit and a few others. Again, I can't say if the One-Spot is this design for sure.

[Mark Hammer]

The most critical piece of information is whther any of the pedals - and especially if TWO or more - are digital, or have a clock of some kind in them.

The One-Spot is quiet and dependable, but may not have the sort of filtering that prevents noise spikes from digital pedals, sharing that power via daisy chain, from causing noise. If what you intend to power is a trio of analog pedals, then you should be good to go with a One-Spot and daisy-chain cable.

[daz]

The most critical piece of information is whther any of the pedals - and especially if TWO or more - are digital, or have a clock of some kind in them.

The One-Spot is quiet and dependable, but may not have the sort of filtering that prevents noise spikes from digital pedals, sharing that power via daisy chain, from causing noise. If what you intend to power is a trio of analog pedals, then you should be good to go with a One-Spot and daisy-chain cable.

A analog OD, a analog chorus and a digital tuner, all true bypass.

[olddawg]

I can't speak to the One-Spot specifically because I haven't been inside one. Typically, however, in this type of pedal power thingy, each jack has it's own separate supply starting at the front end with a multi-tap transformer that supplies several rectifier circuits. Each rectifier powers a corresponding output jack. So, each supply is independent of the other for isolation. I've worked on other brands that are like this. Off hand, I remember a Furman unit and a few others. Again, I can't say if the One-Spot is this design for sure.

Dude... a OneSpot or a Godlyk is not like a Power Brick. It’s simply a small PMPS power supply that takes up “one spot” on an AC power strip. It’s daisy chained to power pedals... no isolation . The only problem I’ve had with them is that they don’t play nice with som digital pedals. I suspect that the chipper transitor frequency beats on the clock frequency. There’s always a little bleed and it’s to fast too hear in analog applications.

[The Dude]

Mick mentioned the One-Spot Pro CS7 in post #2, so that's what I was referencing (link here). There's a gut shot down the page and you can see what appear to be isolation transformers in there, like what I was referring to. It also says "pure isolated power" on the lid. So, maybe we are talking about different things here?

At any rate, your initial idea of trying batteries is a good one. Before even futzing with power supplies, it's an easy way to tell if power is even the issue.

[olddawg]

Mick mentioned the One-Spot Pro CS7 in post #2, so that's what I was referencing (link here). There's a gut shot down the page and you can see what appear to be isolation transformers in there, like what I was referring to. It also says "pure isolated power" on the lid. So, maybe we are talking about different things here?

At any rate, your initial idea of trying batteries is a good one. Before even futzing with power supplies, it's an easy way to tell if power is even the issue.

You are absolutely correct. I thought a OneSpot was a OneSpot. I guess this is their version of a power brick? Seems to have individually regulated and isolated power ports. My apologies. I didn’t know this product existed!

[Mick Bailey]

The CS7 is my new go-to for quiet, isolated pedal power. I have one running three Le Preamps and a torpedo simulator together (a heavy load that will not tolerate shared power) and another one will power the rest of the pedals.

Batteries make no difference to the setup I referred to - the noise is mainly from cables (over 70' of old and tired cable) the guitar itself and a boost pedal. I was using this to illustrate not to assume that a particular power supply configuration is noisy.

[daz]

The CS7 is my new go-to for quiet, isolated pedal power. I have one running three Le Preamps and a torpedo simulator together (a heavy load that will not tolerate shared power) and another one will power the rest of the pedals.

Batteries make no difference to the setup I referred to - the noise is mainly from cables (over 70' of old and tired cable) the guitar itself and a boost pedal. I was using this to illustrate not to assume that a particular power supply configuration is noisy.

What about the idea i mentioned earlier of running the positive to all the pedals but running the neg to the board's signal out jack ground? Would just make the routing and all easier and maybe less likelihood of ground loops?

[The Dude]

You are absolutely correct. I thought a OneSpot was a OneSpot. I guess this is their version of a power brick? Seems to have individually regulated and isolated power ports. My apologies. I didn’t know this product existed!

No apology necessary. We were just talking about 2 different devices. Simple as that.

[Enzo]

Quote Originally Posted by The Dude View Post
If nothing else, a quick test with batteries would tell you if it's the power supply causing problems.


I haven't even begun to put it together yet, thats why i'm asking....so i can avoid a lot of time spent wring a power rail that might cause issues.

So WHEN you get the pedals, slap three batteries into them and FIND OUT what you are up against.