Finding a 120vac/12vac power supply to replace a 12vac walwart

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WireNut

 I could use some help from AC member’s finding a 120vac/12vac power supply to replace my 12vac/6watt/0.33 amp walwart.
The cost of the component I'm trying to upgrade with it's supplied walwart was $400 usd.
I’m not an expert at this. Any help I can get from AC member's would be fantastic.
DIY would be fine, or a manufactured unit would also be good.

I already have a 12vac/2.08amp Triad transformer in a box (nothing else is inside the box) but it has been blowing fuses in my component.
The supplied walwart with my component has not. 

What I’ve found so far for a 12vac supply to upgrade my Walwart is outside the U.S.

Rock Grotto’s Little Pinkie SE, 12 Volts AC, 30VA, costs $194.00 shipped to USA.
http://www.rock-grotto.co.uk/pinkiev2.htm

Swagman Labs: 12VAC Power Supply, Output Current 3A. $120.00 + shipping.
Sounds like a good deal. Maybe to good.
http://www.swagmanlab.com/Product_All?product_id=618&brd=1

Sbooster BOTW P&P ECO 12V - 13.2V, $330.00 usd plus shipping.
I don't know the specs of this unit. It's the most expensive of all.
https://www.sbooster.com/botw-pp-eco-12v-132v/

There must be others available. I just don't know where to look.







srb

Since it's an AC supply, it's basically a stepdown transformer and no additional circuitry is needed.  Some of the ones you listed have additional EMI/RFI filtering, which may be redundant if you're connecting it to a power filter or conditioner.

I certainly wouldn't spend any more than the Swagman and you may be fine with something even less expensive.  Based on the several you've listed, I'm assuming you want an external metal box with an IEC inlet for power cord.

Here's one from eBay with an R-Core transformer and a small filter circuit integrated into the IEC inlet in an aluminum case for < $65 shipped.
http://www.ebay.com/itm/30VA-AC-Power-supply-Power-adaptor-115V-230V-to-AC9V-12V-15V-16V-18V-24V-L164-20-/121955056060?var=&hash=item1c651679bc:m:mmOVe3AFX0VHu7bis5s63zQ

Black front panel available by request.

Steve

poseidonsvoice

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 :o

Nice find Steve!

Best,
Anand.

WireNut

:o

Nice find Steve!

Best,
Anand.

Thanks Anand. I may be beating a dead horse with this :deadhorse:.
Just trying to make my new Vista Phono-2 operate at its best. A couple of years ago Boris mentioned that the supplied walwart
for my Phono-1 ACLE unit was more then adequate.

Maybe the supplied walwart for my new Vista phono-2 is fine. Maybe Not. That's why I'm looking around.

 




poseidonsvoice

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Thanks Anand. I may be beating a dead horse with this  :deadhorse:. Just trying to make my new Vista Phono-2 operate at its best.

Well going with an RCore is the right move here (if you are wanting to tweak). I like EI Core as well but they can be prone to hum, and with the right RCore if obtained with an electrostatic shield, you'll minimize capacitative coupling between the primary and secondaries with less noise issues. I try to avoid toroidal transformers for low level electronics. They are so wide-band that any interference, noise, pulses etc on the mains are transmitted to the secondary side almost un-attenuated. The advantages of toroids - smaller size and less stray fields - are secondary in my view, and those issues can be taken care of easier than trying to filter the mains junk. So RCore it is!

Best,
Anand.

WireNut

Well going with an RCore is the right move here (if you are wanting to tweak). I like EI Core as well but they can be prone to hum, and with the right RCore if obtained with an electrostatic shield, you'll minimize capacitative coupling between the primary and secondaries with less noise issues. I try to avoid toroidal transformers for low level electronics. They are so wide-band that any interference, noise, pulses etc on the mains are transmitted to the secondary side almost un-attenuated. The advantages of toroids - smaller size and less stray fields - are secondary in my view, and those issues can be taken care of easier than trying to filter the mains junk. So RCore it is!

Best,
Anand.

Thanks Anand.
I respect your advise and knowledge. I know you build your own components.
All-tho I'm a 35 year audiophile, I don't know it all. Can you point be in the direction of an RCore 12vac supply?


poseidonsvoice

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Thanks Anand.
I respect your advise and knowledge. I know you build your own components.
All-tho I'm a 35 year audiophile, I don't know it all. Can you point be in the direction of an RCore 12vac supply?

The eBay link that Steve (srb) showed uses an RCore transformer, so you're good, no worries. Just pick 12VAC and you should be good to go since the current requirement for your solid state phono stage should be small. Also make sure that the umbilical cable supplied is compatible with your device. You don't want to find out it isn't after it ships from an overseas location.

Will it sound better? Dunno, honestly. Much of that depends on the Vista phonostage design itself.

Best,
Anand.

zoom25

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Check out Teradak. They have a bunch of stuff. I use their 12V13A LPS.

poseidonsvoice

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Check out Teradak. They have a bunch of stuff. I use their 12V13A LPS.

If there is a link for a Teradak built unit with AC outputs, please share. All that I see from the Teradak website have D.C. outputs which is not what Wirenut is looking for.

Best,
Anand.
« Last Edit: 27 Apr 2017, 10:55 am by poseidonsvoice »

OzarkTom

Re: Finding a 120vac/12vac power supply to replace a 12vac walwart
« Reply #10 on: 27 Apr 2017, 10:16 am »
This is the best for the bucks I have ever used. It even beat a $4oo King Rex PS. This  is built like a tank.

http://www.ebay.com/itm/ASTRON-RS-7B-12V-DC-POWER-SUPPLY-/311737767615?hash=item489504d6bf:g:MiMAAOSwHMJYI3R~

srb

Re: Finding a 120vac/12vac power supply to replace a 12vac walwart
« Reply #11 on: 27 Apr 2017, 10:34 am »
The Astron is a DC power supply.  WireNut is looking for a 12VAC supply.

OzarkTom

Re: Finding a 120vac/12vac power supply to replace a 12vac walwart
« Reply #12 on: 27 Apr 2017, 11:07 am »
The Astron is a DC power supply.  WireNut is looking for a 12VAC supply.

The King Rex is AC, but the Astron on IFI gear is better sounding by quite a bit.

bacobits1

Re: Finding a 120vac/12vac power supply to replace a 12vac walwart
« Reply #13 on: 27 Apr 2017, 02:04 pm »
That SBooster BOTW P&P ECO 12V is a "DC" supply also. It's listed for the Chord DAC's has to be DC.

I'm not going there this time with the Vista Phono2. I have an SBooster 15/16v DC for the Ifi Phono2. The ifi 2 has the special noise cancelling design SMPS supplied with it. I still heard an improvement with the Sbooster. But not in slam. Improvements were in articulation and detail being skin tones on drums and a bit more in separation, staging a bit more 3d, speakers float an image more. This on some material not all. Not a night and day differences but only direct comparisons between  the 2  PS's. Now, SMPS on some systems can return a high level hash back into the line. Never heard that here. The Ifi 2 is extremely quiet satisfying too.
You can always play with the umbilical cable design and DC jack which can make a difference too. I did on the Chord DAC, and it does.
On and On ............

The Vista Phono 2 is remarkable for the price as is. Compare to the Ifi2 ? Yup!!
My opinion and mine only. My equipment my ears and tastes. The thing sings!

But as usual ya just gotta try it.

My question is what does a AC power supply design bring as opposed to a DC PS regardless of transformers etc.
I did not pose this question with Boris.


WireNut

Re: Finding a 120vac/12vac power supply to replace a 12vac walwart
« Reply #14 on: 27 Apr 2017, 03:03 pm »
Great advise here. Thanks so much. BTW, the Vista phono-2 is really good. I haven't had much time with it yet but it's differently better then my Vista Phono-1 ACLE unit.
I'm just considering something other then the walwart so I can use my good power cord. I'm looking into the supply's that were suggested.  :thumb:


 

Davey

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Re: Finding a 120vac/12vac power supply to replace a 12vac walwart
« Reply #15 on: 27 Apr 2017, 03:55 pm »
...........so I can use my good power cord.  :thumb:

Huh?  :)  Let me guess.....your "good power cord" cost more than the Vista preamp did??

It's unlikely you're going to improve the performance of this unit by simply changing out a wallwart.  And there's certainly no need for a big, high current unit when all you need is 300 milliamps.  In fact, the actual load is probably less than that.
AC wallwarts are excellent for this type of application.

If it ain't broke, don't fix it.

Dave.

WireNut

Re: Finding a 120vac/12vac power supply to replace a 12vac walwart
« Reply #16 on: 27 Apr 2017, 04:25 pm »

Huh?  :)  Let me guess.....your "good power cord" cost more than the Vista preamp did??

It's unlikely you're going to improve the performance of this unit by simply changing out a wallwart.  And there's certainly no need for a big, high current unit when all you need is 300 milliamps.  In fact, the actual load is probably less than that.
AC wallwarts are excellent for this type of application.

If it ain't broke, don't fix it.

Dave.

Nothing expensive, it's a Bob Crump/Asylum power cord I made awhile back I'd like to try.
I'm learning a lot about power supply's and transformers that I didn't know.
Below is some info that I found on Mode electronics website that I think is worth sharing.
It just may explain why I damaged one of my components awhile back using a 50VA Triad Transformer.

Quote from Mode Electronics:

Some AC Adapters are unregulated. All voltage ratings shown are at rated load.
For instance a 12volt/500mA unit has an output of 12volts at 500mA.
If the load is less than 500mA the output voltage will be higher.
Exceeding the output current will damage the adapter.

A note about regulated switching power supplies:
Some use a sense return line at the output plug to provide a consistent voltage at the output plug regardless of current draw.
Removing the output socket or cutting the cord on these adapters will remove the sense line and cause the output voltage to soar,
damaging the circuit and voiding your warranty.
Do not modify the adapter.

Unquote.

Davey

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Re: Finding a 120vac/12vac power supply to replace a 12vac walwart
« Reply #17 on: 27 Apr 2017, 05:37 pm »
Yes, that's exactly why you damaged your unit.  (You're lucky you just blew a fuse.)  :)

Transformers have a load and line regulation specification, but this is not the same as (active) regulation that many DC power supplies utilize.

The vast majority of power supplies utilized in audio equipment don't have sense lines.  You usually see this only in systems where the load is a long way from the supply and there is significant IR drop from the cabling.

Cheers,

Dave.