Building a power supply questions - noise reduction

[spargo]

I've heard many say that daisy chaining pedals can cause more noise on distortions, etc.  I currently use a OneSpot (which I think is pretty good for what it does?) to power 8 pedals in my signal chain.  My Boss SD-1 is particularly noisy even when at half gain.  It's fairly obnoxious.

My questions: would an isolated power supply help with this?  If so, what is a good route to go?  I've seen a couple schematics and at first glance some appear to be more isolated than others.  For example, the power supply on tonepad seems to have all the DC jacks hooked up to the same power lines.  Is this okay?  I'm looking for a power supply that could power about 10-12 pedals with clean power (and only one wall plug).  Does each pedal need its own isolated output or can you daisy chain 2 or 3 pedals out of one of the outputs?

For comparison, the Pedal Power 2+ has 8 isolated outputs, but what if I wanted to use that to power a board with 12 pedals with clean power?  Do I need two?

[petemoore]

  Choose some circuits that 'sip with manners' and couple them in a box [or next door to one another].
  Some circuits 'gulp' or chug a lug on the power rails [try BFC there or other filtering], others may not like drinking from the same supply with 'em though, phaser, tremolo...depending...may tick.
  Otherwise when the ground loop didn't grow very far and a boost/fuzz or couple fuzzes tend to behave well when sharing supply power.
  My 9 box effect board played 'hide the very vaguely defined culprit' on me, not a noise problem, but a small, ugly, signal degredation. A 'flea' in a big, hairy pedalboard...I had to trim that beast to find it.
  The extra outputs [total 16] worked out nicely though also, as some of the effects and mixer are bipolar supplied, making power outputs assigned at twice the 'normal' rate.   

[Mark Hammer]

I've heard many say that daisy chaining pedals can cause more noise on distortions, etc.  I currently use a OneSpot (which I think is pretty good for what it does?) to power 8 pedals in my signal chain.  My Boss SD-1 is particularly noisy even when at half gain.  It's fairly obnoxious.

"Noise" is about as vague a term as "music".  What sort of "noise" are you referring to?  Makes a difference, since the source may not be what you think it is, and the recommended solution may vary.

[R.G.]

I've heard many say that daisy chaining pedals can cause more noise on distortions, etc.  I currently use a OneSpot (which I think is pretty good for what it does?) to power 8 pedals in my signal chain.  My Boss SD-1 is particularly noisy even when at half gain.  It's fairly obnoxious.

My questions: would an isolated power supply help with this?  If so, what is a good route to go?  I've seen a couple schematics and at first glance some appear to be more isolated than others.  For example, the power supply on tonepad seems to have all the DC jacks hooked up to the same power lines.  Is this okay?  I'm looking for a power supply that could power about 10-12 pedals with clean power (and only one wall plug).  Does each pedal need its own isolated output or can you daisy chain 2 or 3 pedals out of one of the outputs?

For comparison, the Pedal Power 2+ has 8 isolated outputs, but what if I wanted to use that to power a board with 12 pedals with clean power?  Do I need two?

The SD-1 is a particularly bad pedal in terms of power sensitivity. We use it as a "bad example" for some testing. We have run as many as 75-80 pedals from a single 1Spot for testing pedals without any ill effects.

As for whether daisy chaining pedals is bad for noise in general: it depends on many things, most of which are not the power supply which feeds them. Many people (as in "many thousands of semi- and pro musicians) use a single 1Spot or some other adapter to run a pedalboard of up to 20 pedals with no issues at all. Multiple isolated outputs can offer some advantages on some pedals in noise-critical situations like critical studio settings. It's all in the details of the pedals, the pedalboard, the AC power supply to the board and the quiet - or lack thereof - of the surroundings.

[Mark Hammer]

You've made me curious now.  So what is it that makes the SD-1 a "particularly bad pedal"?  Looking at the schematic, there is nothing that stands out to me, other than the amount of gain at max, and that pales in comparison to some other pedals.

[Labaris]

I have the same questions of spargo.

I'd like to "upgrade" my PS (actually build a new one), and I'd like to make it behave well.

I'm having some trouble right now with a daisy-chain and a buffer connected at the end of it (AMZ super buffer).

How about the size of filtering caps? They must be large enough, but larger values make current rise a lot...


So, sorry if this is a little "off-topic"

[spargo]

The noise I'm referring to is when I switch the pedal on I get a loud "KKKSSSSHHHHHHHHHH" sound. If that makes sense.  Perhaps it's mostly the SD-1... the bluesbreaker clone I built is much quieter, but my Barber Tone Press has more noise than desired as well at higher output levels.

I'm considering building an overdrive based on the tubescreamer to replace the SD-1.

[R.G.]

The noise I'm referring to is when I switch the pedal on I get a loud "KKKSSSSHHHHHHHHHH" sound. If that makes sense. 

Replace the power supply with a fresh 9V battery. If the noise is still there, it's the pedal, not the power supply or daisy chaining. If the noise vanished, could be power adapter, could be daisy chaining, could be the contacts in the DC power jacks, etc.

[R.G.]

You've made me curious now.  So what is it that makes the SD-1 a "particularly bad pedal"?  Looking at the schematic, there is nothing that stands out to me, other than the amount of gain at max, and that pales in comparison to some other pedals.

It's things other than what show up on schematics if I had to guess. And frankly, I have never done a tear-down and reverse engineer on an SD-1. It's just an observation that over time, many people I've consulted have mentioned this. In doing lots of pedalboard setups, testing, pedal swapping, power supply testing, etc, we have found that many times if there is noise to be had, the SD-1 will bring it out. Other pedals, even very high gain ones, will often be acceptably quiet in the same position in the chain with the same power supplies, cords, etc. .

[smallbearelec]

My questions: would an isolated power supply help with this?  If so, what is a good route to go? 

The Small Wart 125.
http://www.smallbearelec.com/Projects/SmWart/SmWart.htm

I just added the adjustable voltage/dying battery version to the article. Either one can be built in two evenings, and they are enormously handy things to have available, particularly for situations such as you describe.

SD

[Mark Hammer]

It's things other than what show up on schematics if I had to guess. And frankly, I have never done a tear-down and reverse engineer on an SD-1. It's just an observation that over time, many people I've consulted have mentioned this. In doing lots of pedalboard setups, testing, pedal swapping, power supply testing, etc, we have found that many times if there is noise to be had, the SD-1 will bring it out. Other pedals, even very high gain ones, will often be acceptably quiet in the same position in the chain with the same power supplies, cords, etc. .

And it is unique in this respect in the universe of TS workalikes?

[R.G.]

And it is unique in this respect in the universe of TS workalikes?

Probably not. It's just one that we noticed. I'm sure there are other bad examples.