Isolate each output on a 1 spot daisy chain

[Ibanezsr500]

Hey guys,

I'm having issues using a 1 Spot and a daisy chain with some of my pedals, so I'm thinking about adding an inline isolation circuit before the troublesome pedal's power input (Sansamp BDDI and Russian Big Muff don't like each other, so I plan on isolating the Muff).

Can I use this? http://au.mouser.com/ProductDetail/Mean-Well/SPR01L-09/?qs=l0g2inPJSHP1Kb%252br85qaug0zCll9vWJF

I can't find the input voltage, but the 5V-5V version is 5 volts in and 5 volts out, so I'm assuming that this 9v version would have the same 1:1 ratio? Somehow I don't believe that they can regulate power without ANY voltage drop, but who am I to question it... Is this going to isolate the power or will it just regulate it even more?

Oh, and I'm doing this specifically to avoid buying a $250 isolated power supply, although I have a bad feeling that it might be the only option, apart from going back to batteries...

Thanks,

[darron]

Yep! I started playing with those. I'm on my phone now, so not sure about that particular one. The ones I used were isolated beyond 1000V

I could believe they don't have a voltage drop, because they are not just regulators. They will be switching at very high frequencies and using a coil, so they could switch whatever they want on the output.


The one I used had a bit of whine with high current pedals like a Boss Chorus or something. I use a 12v output into a regular 9v regulator with plenty of capacitor filtering. Note they can only take handle so much capacitance on the output also. I think I'd have to look into using inductors to make it quieter. Haven't picked the project up for a while.


Keen to see how you go!

[R.G.]

I'm having issues using a 1 Spot and a daisy chain with some of my pedals, so I'm thinking about adding an inline isolation circuit before the troublesome pedal's power input (Sansamp BDDI and Russian Big Muff don't like each other, so I plan on isolating the Muff).
...
Oh, and I'm doing this specifically to avoid buying a $250 isolated power supply, although I have a bad feeling that it might be the only option, apart from going back to batteries...

I've seen some pedals that don't play well together on daisy chains. The vast majority do, but there are exceptions, and the number of possible combinations and permutations is astronomical.

One thing you might want to consider. We've had good luck with using a second 1Spot for curing problem pedals. True, it's not as sophisticated as an isolator per output, but once you get into the price of an isolator and then putting jacks on it and making some kind of enclosure for it to go in, the price difference decreases. I don't know what the taxes and import duties, etc. do to the 1Spot in Australia, but in the USA you can get a 1Spot for about US$20 and a combo pack with the power supply and a batch of adapters for US$27. Sometimes a group of offending pedals don't offend each other when put in the "problem pedals" daisy chain, which I thought was odd.

There are an infinite number of ways to get noise.

[Ibanezsr500]

A 1 Spot combo pack in Australia costs about $60. I think I'm gonna buy one of the regulators just to see what I can do with it, they look fun. I'm gonna stick the regulator in the Muff permanently, so jacks and stuff aren't neccessary. Thanks guys, its appreciated.

[R.G.]

A 1 Spot combo pack in Australia costs about $60. I think I'm gonna buy one of the regulators just to see what I can do with it, they look fun. I'm gonna stick the regulator in the Muff permanently, so jacks and stuff aren't neccessary. Thanks guys, its appreciated.

Wow. That's incredible. It more than doubles the price. Governments do interesting things.

Certainly, if you can stick an isolating regulator inside it for $10, skipping the enclosure and jacks, that's going to be a lot cheaper.

[Ibanezsr500]

Yeah, most music stuff is more expensive over here compared to in the States. 

Back on topic, Do i have to use any other components, or can i just plug the regulator directly in line? (which sounds way to easy to be possible)

If I have to build a circuit, has anyone got a diagram for me?

[Ibanezsr500]

Just found the input voltages, it says 4.5 - 5.5 volts 

Any suggestions?

[darron]

yep. that's my experience. two pins in and two pins out. obviously they should have nothing in common like a common earth/negative. a bit of additional filtering might be wise as there's probably bugger all in that little SMD IC package. They can't handle too much like 1,000uF though.

all here:

http://www.meanwell.com/search/spr01/SPR01-spec.pdf


NOTES at the bottom:

1.All parameters are specified at normal input, rated load, 25J¢
2.Ripple & noise are measured at 20MHz by using a 12" twisted pair terminated with a 0.1uf & 47uf capacitor. 3.Load regulation is measured from 10% to 100% rated load.
4.Please prevent the converter from operating in overload or short circuit condition for more than 30 seconds.

[darron]

Just found the input voltages, it says 4.5 - 5.5 volts 

Any suggestions?

i had that issue. i ended up using 5V ones up to 12V. also, when i used 5V with a schotttky protection diode (~4.9V) it influenced the output quite a bit. different IC though probably. 5V was a good choice though because everything is 5V these days like USB etc.

since the efficiency is already absolutely terrible, you could use a 78L05 prior with a small cap between the two? still very simple you could wire it up without even needing any kind of circuit board inside a box. point-to-point.





keep us updated! i want to know if the results are better than mine. i had a bit of whine on high current pedals. i used a 12V isolated into a 78L09 and it still pushed through a tiny bit.

[Ibanezsr500]

Thanks mate, thats definitely cleared a few things up.

Yeah, I think that the 78L05 is the best choice, now I've got to find somewhere that sells the SPR01L-09 regulator that doesn't charge me $40 in shipping!!! Seriously mouser? It costs you $40 to ship a 5 gram part, really?!?

EDIT: I'll be sure to keep you updated, though it might take a while for the parts to arrive, unless i can fin them in Australia. As for high current draw pedals, i don't think that the Muff draws that much, if it does I'll try it with the sansamp, that draws next to nothing IIRC.

[darron]

Check RS components (Australia). They have the biggest catalogue I've ever seen and free shipping. I'm on my phone now, send me a message if you need help finding so etching because its so daunting...

[Ibanezsr500]

I couldn't find the SPR01L-09 regulator that mouser had, I could only find this: http://australia.rs-online.com/web/p/isolated-dc-dc-converters/6894892/   - $25 is a bit steep though...

[darron]

i was using the recom ones. a bit over $10 each. don't think there was a 9v one for the series i was using but there should be something.

[Ronan]

With a lot of respect, I really feel you are going about solving your problem the hard way. It is much easier to just buy a 2nd power supply (Boss or whatever) preferably 2nd hand from gumtree or ebay, and use that to run the problem pedal/pedals.

Switching/isolating IC's/circuits are IMO a last resort in the DIY world, there is no magic to be found.

[darron]

can i hijack the thread and ask what people would suggest would be a good inductor to use for filtering for such a switching isolator? i'm not too familiar with inductors and how much mh/uH is appropriate.

i think that's where i got stuck last time i tired this and i'd like to overcome the problem.

[Ibanezsr500]

With a lot of respect, I really feel you are going about solving your problem the hard way. It is much easier to just buy a 2nd power supply (Boss or whatever) preferably 2nd hand from gumtree or ebay, and use that to run the problem pedal/pedals.

Switching/isolating IC's/circuits are IMO a last resort in the DIY world, there is no magic to be found.

Yeah probably, I'll have a bit of a think about it before I go buying parts. I might just run a battery in the Muff for a while until I can buy an isolated power supply which would solve all my problems, and any further issues that could arise in the future when I inevitably add more pedals to my board.

[Ronan]

Yes that's the main point, inevitably more pedals get added/swapped out. Most pedals run fine together I have found, usually its the ones that have digital chips or some sort of voltage doubler inside that cause problems, that's why I think its easier to have a spare power supply (or 2) just sitting around in case. That way, the pedals that really need isolating from the others can have their own isolated power supply, and usually its just one or 2 rogue pedals that need it. But, there's a 100 hundred ways to skin a cat, each to their own. Just my 2c.

Darron, can't help you on your question sorry, thats way over my head, but if you have an old wah inductor lying around, and the current draw is very small...or the primary of a small 240V tranny...

[Ronan]

A 1 Spot combo pack in Australia costs about $60. I think I'm gonna buy one of the regulators just to see what I can do with it, they look fun. I'm gonna stick the regulator in the Muff permanently, so jacks and stuff aren't neccessary. Thanks guys, its appreciated.

Wow. That's incredible. It more than doubles the price. Governments do interesting things.

No, its not governments, it is the re-sellers, or maybe the Australian demand is so low we pay for it due to the economy of producing low numbers. Not sure if euro plug is same as Oz?  I live in Australia, I can get a US 1-Spot shipped to me for $20 total, which I did. An Australian version does cost $60. I forced my US one into the Ozzy power board to modify the angle of the pins. Works very well. Not recommended but works. If it doesn't work, you can box the whole 1-Spot and fit a 240V lead and plug to suit local outlets, for a lot less than the extra $40, or just use an international adaptor...  In Australia, a US 1-Spot becomes a 2-Spot though, it covers the next outlet.

[greaser_au]

Not sure if euro plug is same as Oz?

Us here in Australia and our good friends in the 8th state (New Zealand)* use a plug in conformance with AS/NZS 3112, not at all similar to the euro plug, unfortunately. Everything you never wanted to know about mains plugs across the world can be found here http://en.wikipedia.org/wiki/AC_power_plugs_and_sockets

david

* I'm kidding...  the Kiwis (whose 2 main land masses are North and South Island), refer to Australia as West Island...

[Ronan]

Thanks. The 1-Spot is rated for 100VAC to 240VAC input, 50/60Hz, so I guess an international adaptor is the way to go. Thinking about the volume of sales in Australia vs the sales in USA, I guess we are lucky its only $60 vs $20, because they would have had to make up a different case for the Oz market with a population around 7% of the USA.