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I've always been a fan of Musical Fidelity equipment because of many things one of which is their power handling...choke regulation etc. I've owned several pieces and have been very happy with them. But their equipment of late is powered with wall warts. My X10v.3 has a wall wart. My question is, how can these wall warts supply clean power without adding "stuff" back into the power grid of ones stereo system. And how would one upgrade in this area.
So this X-can runs on 12 vac ? I didn't see any diodes or filtering , just a torroid and fuses . Most wall warts are suppling DC voltage at a specified amperage .
They are usually made with just enough capacity to get by, which is not enough for most audio applications. The linear ones have too little transformer core and will generate noise from core saturation with higher line voltage. The rectifier diodes will generate noise as well (this is true of any linear supply using p-n junction rectifier diodes). The mechanical arrangement of having something heavy dangling from the outlet invites vibration problems.
There are also switching wall-wart supplies, and these are horrid sources of RF noise.
As bartc said, it is easy to make your own superior supply. You can buy a laboratory regulated supply for the same output voltage, but this will still need some sort of filtering at its AC input to keep its noise out of your AC.
How about some more details on that regulated supply...where and how to buy. I'm not sure what to think about MF now that they have gone to these things. To me it doesn't speak"quality" like previous MF equipment did.
For example, Mouser sells one from B&K Precision for $225. Part number 615-1621A is a single supply that can produce 0 to 18 volts at 0 to 5 amperes, and is switchable for constant voltage or constant current. It has a digital display. For $220, part number 615-1626A is rated for 0-30 volts at 0-3 amps, and has analog meters.
There may be cheaper versions of this kind of supply around: check the electronic supply houses. The DC from these would be far superior to that from a wall-wart, but you still have to deal with any AC noise they generate. You can build your own, but you would have to know where to find surplus parts cheap to make something that costs significantly less and works as well.
I'm not aware of any audio equipment manufacturer that does not cut corners somewhere. Any piece of equipment can be tweaked to sound better, and it is sometimes the hideous prices that prevent more audiophile tweakers from experimenting with the snootier gear. The retail price is some multiple of the manufactured cost, so a few dollars extra spent on parts turns into a much higher retail price. If the wall-warts create a bad impression of the MF gear, look at the competition carefully to see where they have avoided spending money.
Diff is that he's in the UK where the voltage is 220, but otherwise with the US plugs and right 110-12v AC transformer, any of these would work better than ths standard wall warts. Key is much higher amperage capacity than the standard, so that the device can draw easily when it peaks.
The wall warts are deficient in 2 ways: they don't filter and they don't usually deliver the stronger power with which the MF units thrive (read the archives here and in Tweaks about this).
I have the MF X10d. Got it used with a stronger amperage wall wart than the standard and it was OK. But I built a torroidal power supply (took maybe an hour) from available materials and it's a winner! No surprise, as that's exactly what others report.
There are lots of recipes for this. Try Tweaks but also try a Google on this.
Meantime, if you really want to do filtering and especially for lower draw digital units, read up on Jon Risch's Super Quick and Dirty Isolation Transformer. This is not suitable for high power draw equipment, unfortunately.
I've got it plugged in to an Ultimate Outlet. I wouldn't want to spend several thousand on one of the new set-ups from MF with those kind of power supplies.
Did you notice a difference with your new power supply?
Exactly what's been posted consistently before and I like it. No big deal to DIY power supplies if you figure out how. Not expensive either. I don't think you need their $399 PSU unless you don't know how to DIY.
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