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Does any one know of a after market power supply for the Cambridge Audio Dacmagic? I am looking for an upgrade here. I don't want another wallwart. Thank you in advance for your help
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The dacmagic's wallwart is a 12V AC power supply. An easy upgrade would be to get a nice toroid as a replacement. I did exactly that (together with a nice metal box, IEC, fuse and wire out towards the DacMagic) and it was a worthwhile and economical upgrade.
Eduardoo
Could you please explain exactly what I will need.Thankyou for your advice. I know I can build the power supply with a little help. Can you suggest any books I should pick up.
The thing that makes this easy is that its an "AC" supply. When you say power supply, most people will think of a DC supply, which needs rectifiers, filters, regulators etc. An AC supply is basically just a fuse and a transformer.
Its much simpler but that also means you are at the mercy of whats inside the DAC for the other parts. The best you can do is feed them clean AC and let whats in the DAC do the rest.
My personal take on this would NOT to use a toroidal, they are wide band devices and tend to pass on most of the crud on the power line. The more traditional "EI" transformer has nowhere near the bandwidth, which is actually good because it tend to block a lot of the mains noise.
I would also add a snubber across the transformer secondary which prevents it from ringing when hit by the current spikes which will almost certainly come from the DAC. These are very simple, its just a resistor and capacitor wired across the secondary of the transformer.
If you are in the US, these are the parts I would get, they are available from mouser.com:
Transformer: Triad VPS24-1800 Mouser no. 553-VPS24-1800
Resistor: Xicon 330 ohm Mouser no. 30BJ500-330
Capacitor: Sprague .022uf Mouser no. 75-715P200V0.022
You also need a IEC inlet and fuse holder. There are many to choose from. The ones in eduardoo's picture are fine. You can also get IEC inlets that have builtin fuse holders which might make things even easier.
I'll send a schematic later.
John S.
Here is the link to an earlier post of mine relating to the "upgrade" PS.
It is very simple to build (although I did not do it myself), and the only part that you don't see in the picture would be the toroidal transformer.
I had no idea a power supply could be made that easily. Thankyou again for your help. I'd will put my own together before I'll buy one.
Its 12V AC? I just saw the 12V at 1.5A, AC is a whole different ball game from what I was recommending.
Thanks for bringing that up.
John S.
AC indeed. If you want to buy one that is "factory built", Russ Andrews of England makes one (likely 220VAC) that is bigger than the stock one, but still looks like a plastic wall wart (except that it has a wire attached and doesn't go on the wall).
Just look at the price; get a linear lab power supply. These are the same people who put 80 uF across live and neutral in their 'super' mains suppressor.
Are you up to building one yourself? I have a design that should work very well with that DAC.
The design is over in the computer audio asylum if you want to take a look. If you are up to it I'll post the exact parts necessary here.
John S.
John and Ed
thankyou for the idea to build my own. I have never built anything like a power supply but am sure I can do it with instructions. Yes please list anything I'll need to accomplish this task. I have built a crossover before wheredoes this rate as compaired to a crossover.
Thank you again Steve
You asked for a source. Here it is
http://cgi.ebay.com/MASTECH-HY1803D-DC-POWER-SUPPLY-VARIABLE-0-18-V-0-3-A_W0QQitemZ140320227105QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item20abbcbf21&_trksid=p3286.c0.m14&_trkparms=72%3A1205%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1308%7C301%3A1%7C293%3A2%7C294%3A50
These PSs can beimproved by additional bypassing at the output. You must take the precaution of locking down the output voltage to what you need - tape? Remove knob?
Thank you to everyone for your help! I can't wait to start building this PS and then use it.
Steve
FYI, the Dacmagic needs an AC power source, not DC.
However, this does look interesting for other DC wallwart supplied equipment.
Or get a good linear regulated PS. A flexible approach is to buy a used laboratory supply with voltage and current displays.
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