For a future project I need 30W @ 240VAC. I bought the above early to try something out. Specifically, I was curious how using it would affect the A18's power factor, measured at the wall (this loosely represents the quality of the waveform the A18 receives)
Plugged in with effectively no adapter, the A18's power factor is 0.80
When
this little thing is put in its path, power factor at the wall is 0.76
On the A18's rear, consumption is listed as 350 watts. Since W isn't always VA, and definitely isn't when it comes to transformers in audio amplifiers , I'll extrapolate (re: all the other amplifiers/AVRs/schtuff I've ever seen - stuff designed by courteous people who decided to include all the pertinent facts!)
My Arcam A18 toroidal transformer VA rating approximation: 470VA to 500VA
This "70WATT Max" (lol) device (which measures 2 inches wide 3 inches tall, and maybe 1 and 3/4 deep), probably has a 50VA transformer in it.
I was curious - what happens to power factor when 10x higher rated + inherently superior transformer is attached.
Answer? It drops 0.04 (oops, I put it at the beginning... lmao!). Not bad!
I honestly thought it was going to be a lot worse. This is relatively good news for the shape of the waveform. Now I'm not so set on getting 1600/1800/2000/2400W toroid - the 500VA one will probably be sufficient. Of course, I'll check how its AC output behaves with my scope when I get it - if it drops too much I'll have to exchange it
Some other information:
After this little guy powered A18 for 8 hours straight at basically idle (19.0W) {you could consider this background music level as well, because most amplifiers, when outputting less than a watt per channel, usually aren't drawing any more than +5 watts (above idle) from the wall}, the hottest external spot on the adapter is at the front under the outlet, and varies depending on the exact location - the top half of the front under the outlet ranges 53 to 58 deg C, while the rest of the package is is 30-45 C. Knowing this, the hottest part of the transformer inside is probably somewhere around 70 C. This makes me think that the "70WATT Max" rating is "Max" in the traditional sense. As in, Pyramid car subwoofer amp "Max" - it's actually rated for "35 watts maximum continuous power" lol. And then, even
that is probably a bit of a stretch... Everyone knows that when electronics start getting toasty they give off a smell... This smell isn't necessarily a bad thing - most often it's just a few VOCs evaporating. If temp is
above specifications though, and it's not just a few VOCs you're smelling, but the insulation on a coils? Then you're screwed. There's usually a difference in smell - and even if a component's cooking smells very similar to its burning, the rapid onset and severity is usually enough of a clue. Unless you're going WAY overboard - then you don't even smell it 'til it's fried!
there's an internal switch?!
