What Does 'Isolated Output PS' Mean?

[Transmogrifox]

A lot about converting from mains supply, but haven't seen any comments along these lines:  you could make an array of isolated outputs from a single 12V DC wall wart supply with several isolated DC/DC converters:
http://www.mouser.com/ds/2/632/DS_PA01S%20series_09132012-349619.pdf

They are not cheap, but really dumb-as-rocks simple to use and probably worth it if you can afford $5 per output.  Alternatively you could make maybe 2 or 3 truly isolated outputs with the isolated DC/DC converter for problem pedals and then power the rest of your pedals with a more typical (cheap) 7809 off the main 12V supply.  You might end up cheaper using something like this instead of a 3-output transformer if you have to order the transformer and buy it new.

The main advantage to the isolated DC/DC converter is you don't need to mess around with mains voltages.  You also don't need as large of capacitors because you're filtering typical 90 kHz converter noise instead of 110/120 Hz mains hum.

A second advantage is that you can add isolated output channels as you need them just by plugging another DC converter module onto the 12V bus.  If  you have a 3 or 4 amp rated 12V supply then you probably won't run out of power unless you run a huge pedal board...but then if you do you replace the 12V supply or add another in parallel to help out.  Either way it makes for a simple modular system that you can increase in small amounts as you need to add capacity.

[EBK]

A lot about converting from mains supply, but haven't seen any comments along these lines:  you could make an array of isolated outputs from a single 12V DC wall wart supply with several isolated DC/DC converters:
http://www.mouser.com/ds/2/632/DS_PA01S%20series_09132012-349619.pdf

They are not cheap, but really dumb-as-rocks simple to use and probably worth it if you can afford $5 per output.  Alternatively you could make maybe 2 or 3 truly isolated outputs with the isolated DC/DC converter for problem pedals and then power the rest of your pedals with a more typical (cheap) 7809 off the main 12V supply.  You might end up cheaper using something like this instead of a 3-output transformer if you have to order the transformer and buy it new.

The main advantage to the isolated DC/DC converter is you don't need to mess around with mains voltages.  You also don't need as large of capacitors because you're filtering typical 90 kHz converter noise instead of 110/120 Hz mains hum.

A second advantage is that you can add isolated output channels as you need them just by plugging another DC converter module onto the 12V bus.  If  you have a 3 or 4 amp rated 12V supply then you probably won't run out of power unless you run a huge pedal board...but then if you do you replace the 12V supply or add another in parallel to help out.  Either way it makes for a simple modular system that you can increase in small amounts as you need to add capacity.

Interesting idea, but if simplicity and expandable modularity are desired, I prefer the method I suggested earlier: http://www.diystompboxes.com/smfforum/index.php?topic=116436.msg1077984#msg1077984 

[Ben N]

I'm surprised no one has mentioned this yet: https://www.tedweber.com/wpdlxfmr-2

[Rob Strand]

They are not cheap, but really dumb-as-rocks simple to use and probably worth it if you can afford $5 per output. 

Those things often not what they are cracked-up to be.   I've worked on projects where someone has used these (not necessarily those exact ones) and they  (1) blow up and (2) produce high frequency magnetic fields which get into every small loop of circuit (E proportional to B and f).   They do this because they use unshielded inductors.  Sometimes you have to add external inductors and caps to pass emissions.

Look at the notes in the data sheet.  They require a minimum load.   Also note that they are only protected for 0.5sec short circuit.

My advise is use with caution.

[EBK]

I'm surprised no one has mentioned this yet: https://www.tedweber.com/wpdlxfmr-2

That's beautiful!

[Ben N]

As for the independently-regulated-but-not-really-isolated DC-DC route, check out http://www.muzique.com/power.htm also, for the schematic and/or for the PCB. Jack Orman has a long relationship with this board, and his stuff is good.

[EBK]

I'm surprised no one has mentioned this yet: https://www.tedweber.com/wpdlxfmr-2

Any idea why the TedWeber wpdlxfmr-2 transformer is cheaper than the wpdlxfmr-1?  The only difference I see is the "-2" has a multitapped primary for 120/220/240V operation, while the "-1" just has a 120V primary.  Shouldn't that make the "-2" more expensive?

[Agung Kurniawan]

OK that is good information.  If your power supply is not dropping out, I'm not sure what is going on.

I thing my ps were dropping out.
my delay have a switch to connect the PT2399 to +5V. when connected, my Boss MT-2 LED dim a little bit. when not, the led bright is normal (atleast a bit brighter)

1) How close is the power supply transformer to the effects pedals?

Try:
- move the power supply box close to the effects and see if it gets worse
  and away to see if it gets better.
- also try many different orientations of the power supply box hold it in you hand
  and rotate it on all axes.

If you hear any changes in the humm then maybe you have to move the transformer
far from the effects and cables.

2) Is the power supply 0V connected to the mains ground?
If it is you need to disconnect the grounded 0V connection as this forms a ground loop (causing humm)
through your amplifier.

the transormer distance and orientation doesnt help,

I connect the 0V to my fx chain (only from one point as I say above) ground wich connect to my amp. I connect the amp ground to the chasist, and connect the chasist to earth outside my home. so, the 0V is connected to the main ground
I live in Indonesia, we doesn't use the ground from the main socket

disconet the 0V would make my fx doesn't work, right?

[wavley]

I'm surprised no one has mentioned this yet: https://www.tedweber.com/wpdlxfmr-2

I built a power supply for my board using two of those, it's fantastic.

Unfortunately, RG has taken the Spyder stuff down from Geofex because too many folks proved that they really weren't ready to work safely with line voltage out of the wall.

[Rob Strand]

I thing my ps were dropping out.
my delay have a switch to connect the PT2399 to +5V. when connected, my Boss MT-2 LED dim a little bit. when not, the led bright is normal (atleast a bit brighter)

It looks like that is the problem.  It doesn't look normal.
(The Boss MT-2 is a modern Boss effect where the 0V and ground are connected.  The older Boss effects have a resistor between 0V - with the old Boss pedal a single 0V connection might show the dim led.
http://stinkfoot.se/archives/726
So you shouldn't have a problem.)

If you are using the 1A 9V power supply with 18V transformer you built about two weeks ago I am very surprised it is dropping out.    You had a 4700uF capacitor on that didn't you?   If the regulator is getting hot it might be shutting down and causing some weird behaviour.

I connect the 0V to my fx chain (only from one point as I say above) ground wich connect to my amp. I connect the amp ground to the chasist, and connect the chasist to earth outside my home. so, the 0V is connected to the main ground
I live in Indonesia, we doesn't use the ground from the main socket

disconet the 0V would make my fx doesn't work, right?

OK, I understand, your current set-up shouldn't  be causing any problems.