SF-2 Power Problem

[jix]

Hi all.
 
So, whilst setting up my rig this morning for a practice, I accidentally forgot to plug my SF2's original US wall wort into the step-down transformer for it to work in the UK, and plugged it straight into a normal US to UK Plug adapator.
 
Needless to say that it didn't work, and when no sound came out of my bass I noticed that the light for the SF2 wasn't on. When the SF2 was taken out of the signal chain everything was fine - lots of lovely bass sounds.  
 
So, I'm guessing that the UK mains has fried something.  
 
I've read on other posts that there's a choke that goes in the SF2 if you get the polarity on the power supply wrong - however, those threads also say that the green light on the front of the SF2 would still be on (and mine isn't)  
 
Could it be that the wall wort was fried? (I don't have another 15vdc supply to try with my SF2 but could buy one). Otherwise, I'm assuming it has to be something inside the SF3 which I'm guessing would need a tech to look at and fix.
 
Any help and suggestions would be very welcome.
 
Thanks very much
James

[sonicus]

You can test the wall wart power supply with a Volt Meter / Multi-meter.

[mike13]

You have fed 230vac into a 110volt input,either the fuse has blown easy to fix or you have cooked the power trans not so easy
Mike

[jix]

Thanks both of you.
 
Having tested the wall wort it does look to be fried (either that or my multimeter is also on the blink!  )
 
I'll get a replacement wall-wort (a UK one this time with the correct voltage - would this work? http://uk.farnell.com/multicomp/ad-1550r/adaptor-reg-15vdc-500ma/dp/1176259 ) and see if that sorts the problem out. Fingers' crossed it will!
 
Thanks very much again
James

[sonicus]

Perhaps Alembic management can verify the  required proprietary specs for you OR perhaps a correct replacement might be available through their resource. This  might be your fix .

[slawie]

There are a couple of gotchas that can be in play here;
 
Polarity of the output i.e. centre pin +ve or -ve
Get it wrong and fry the device (SF2)
Output current capacity needs to be the same usually
printed on the power supply and measured in mA (milliamps)
 
Wait for the advice from Alembic before plugging
anything different into the superfilter.
 
I know this doesn't help to resolve the problem just avoids compounding and further destruction.
 
slawie

[jix]

Thanks, everyone.
 
Having a decent look at the back of the SF-2, the input voltage goes between 10.5 and 19.5 VDC. So, I'm assuming that you could use any supply with a voltage output between this range.
 
Just seen this post from Mica on the subject that seems to support that - http://club.alembic.com/Images/16271/26905.html?1144123979 although I'm curious as to what difference sending 10.5v would make compared to 17v.
 
As for the amperage, based on the wall-wort that I have fried, any supply with at least 200ma would work (if the other supply had a max output of 300ma then the SF-2 would draw what it needs and leave the rest - based on my limited knowledge of electricity).
 
Thanks for the point on the centre-pin, though - need to make sure that the centre-pin is positive.
 
Who'd have thought it could all be so complicated just to power-up a bit of your rig.  
 
Cheers
James

[JimmyJ]

James,
 
You are correct about the current requirements, it needs to be at least 200ma so the supply you linked to from Farnell would work.  It looks like that one also has reversible polarity on the connector end so just be sure you've chosen correctly before you fire it up.  
 
The 10.5 - 19.5v likely means there is some onboard regulation or simply that the device doesn't mind as long as you are within that range.  I would go with whatever voltage the original supply delivered.
 
My opinions shouldn't be taken as gospel, wait for confirmation from more qualified Alembic personnel!
Jimmy J

[mica]

As Jimmy said, there is an onboard regulator to accept the wide range of power supplies. So anything in the range will sound exactly the same.  
 
Parroting the warnings about polarity, so do get that center contact positive before plugging in.  
 
While there's a chance that something else is damaged in your Superfilter, it's not likely. You'll probably be happier having one less thing to deal with by eliminating the extra transformer, and you'll need the power to see if everything else is OK.  
 
Please report back when you have tested it.

[jix]

Thanks very much for all the help everyone.
 
Mica - thank you especially for letting me know that about the power supply.
 
With the original wall-wart definitely toasted, following what you've all said, I took one of my multi-voltage PSUs and set it to 12v (it's max voltage), with the correct polarity. So 12v, 300ma - the SF-2 all seems to work just fine! PHEW!!
 
I'm still hunting around for a PSU that is the same voltage and amperage as the original (but a UK one) just to be on the safe-side, but I think I may have been very lucky this time round!
 
If I use the 12v supply then it would need to have a bigger amperage output than a 15v supply. Not sure really how much amperage the SF-2 needs, and I do want to make sure that the SF-2 gets nothing but the best power!
 
Anyway - thanks again for all the advice and support; it's good to be fully up-and-running again!  
 
Cheers
James

[sonicus]

I am very happy that our collective efforts have been useful  for your positive results .  
 
                   Cheers ___

[jacko]

James. take your old PSu into your local Maplin and show it to their tech guy. I've found if you talk to the right assistant they're usually able to find exactly what you need.
 
Graeme