Isolated stompbox power supplies sharing a board, share the ground plane? Or fully isolate?

[ttttt]

Yeah, this is a good point. Thanks for joining the conversation. Welcome!

Thanks! About 3 years ago I bought a couple of these transformers to make an isolated supply but I have way too many projects and haven't gotten to it... yet.

 

[TheJames]

I went the easy route and got a Voodoo Lab Pedal Power unit and never looked back. I was amazed at how much cleaner the sound was from my guitar setup with the Voodoo Lab supply. Previously I was using a "One Spot" with a daisy-chained power cable. While that wasn't particularly noisy, the Voodoo Lab supply was amazingly cleaner. This would be a good general DIY project. No reason the community couldn't make a really good pedal PSU.

 

[kato]

I went the easy route and got a Voodoo Lab Pedal Power unit and never looked back. I was amazed at how much cleaner the sound was from my guitar setup with the Voodoo Lab supply. Previously I was using a "One Spot" with a daisy-chained power cable. While that wasn't particularly noisy, the Voodoo Lab supply was amazingly cleaner. This would be a good general DIY project. No reason the community couldn't make a really good pedal PSU.

Voodoo Labs is one of the companies known for using full galvanic isolation: separate secondary windings for each independent power supply.

I'm glad you brought them up; earlier in this conversation, one of my comments was taken out of context for no apparent reason. So, I should clarify to my friends and engineers @amplexus, and @moamps that I wasn't talking about the engineers in this group. I was talking about the product engineers at companies like Voodoo Labs who've been making a product with separate secondaries for 20 years.

They don't tout that feature explicitly in their marketing materials. But if they got pressure from another dept. to cut costs, and if it truly made no difference to the product's performance, they would save a buck on the transformer. No doubt.

[Excitement abounds! I'm just going to remove my offending comment because I think we're simply having a communication breakdown. To John's point: I'm not attacking anyone's character. I have nothing but love for all you gentlemen and a fairly thick skin. But purposely (?) misrepresenting someone's point for the sake of picking a fight doesn't belong in a technical discussion. It doesn't even belong in that place with the sticky beer on the floor.] And no, asking someone not to make fallacies of relevance — in essence, to do better — is not an ad-hominem attack.

I think the lesson for me is that when your gut reaction is not to respond to trolling, follow through and don't respond. If someone's signature file — going on more than a decade now — is about "being right," they're probably telegraphing their own personal issues that have nothing to do with you.

Thank you to everyone who showed up genuinely to participate in this discussion. I appreciate your input. Sorry for the airborne toxic event that polluted an otherwise productive discussion.


Edit: After this thread was closed, I got a private message from an audio engineer—one I've known by name for decades—that there is value in leaving the ground jumping pads, which I did.

I would put in pads for a 100 ohm resistor to link the grounds and maybe even a .1U cap, just so you have them, having them lightly tied together might be good for safety, hum, and popping when plugging them in. They can be open, the R, a jumper, a cap, or R and C.

 

[abbey road d enfer]

EMI induces currents in said loop. The signal line will not have the same currents and therefore there will be differences between the signal and 0V line voltages which equates to noise.

Instead of being coy, why not just explain how to "think it over"?

Unless you install your pedal board on top of a power amp or close to a transmitter, or introduce multiple earth connections, the voltages developped in the loop is negligible.

 

[abbey road d enfer]

Here's some reading material for Abbey.

Do you think it's relevant to my behaviour?
I'm glad moamps gave a pragmatic explanation to something that I've always seen tauted as a magical receipe. I can see that it is relevant for some pedals their designers have permitted to inject crap on their power inlet.
Many people buy those expensive power blocks expecting them to solve problems that are not related to power pollution.

 

[JohnRoberts]

@kato from your link offered to Abbey

Arguments of this kind focus not on the evidence for a view but on the character of the person advancing it; they seek to discredit positions by discrediting those who hold them. It is always important to attack arguments, rather than arguers, and this is where arguments that commit the ad hominem fallacy fall down.

Do not confuse marketing hype for solid engineering. Offering to school Abbey on logical fallacies is very wrong for many reasons, so stop.
===
But the logical fallacies do deserve more attention in the brewery.

JR