Random: DC offset and tweeters

So here I am testing an amp which the buyer complained that one channel keeps going mute until the he knocks the amp chassis. Even when I personally use every single piece of equipment right before the transaction, shyt happens.

The left channel has a DC offset of 60mV, if my Minipa multimeter still can be trusted - that reminds me, I need to buy a new multimeter. 60mV is on the high side, but I've seen amps with 100mV and the speakers are fine.

It's usually the tweeters that die from anything - small excursion and low heat dissipation ability means it's the one that die first.

But then I realized, to kill a speaker with DC, the DC has to reach the speaker first. Tweeters have a low pass filter which usually involves a blocking capacitor, so no DC will ever reach the tweeter.

So that means I only have to worry about the woofer. And at 60mV the amount of heat is so low compared to the amount of heat the speaker has to dissipate at full load (speakers are very inefficient devices) it doesn't matter. (You can do the maths.)

Still, I'm leaving my multimeter hooked up to the speaker terminals (in case it decides to rise to 100mV or what). The good part about bi-wireable speakers is that the second pair of connectors can be use for anything useful.

Dead blog revival and a change in direction

The last published post was... 6th of September last year and it wasn't even a full review. Also, 3 posts between June and September and none thereafter.

I was clinically (figuratively or literally?) addicted to World of Tanks in the past 6 months. I played whenever it was possible. Didn't study as much (well previously I would study when I got bored enough, which happens fairly easily), watched almost no Anime, and didn't do all the stuff that needed to be done when I have free time. Well, things are going to change for the better.

Anyway, back to the blog. Yea, WoT is probably the main reason why I didn't post anything for so long, but there is more to it. Originally this blog was titled "wwenze's tech, audio and Anime rant page", but around 1.5 years ago I decided to act more professionally, renamed the blog to its current name, posting mostly reviews and such kind of stuff and avoiding talking about Anime. But "reviews and such kind of stuff" posts are hard to come by, because products and discoveries are hard to come by and even if I have the product the capability to make a good review is hard to come by. So naturally posts become few and far between.

And audio... well audio is the main meat of this blog. However the more I know about it, the more I think it is stupid (the industry, not the science), and the less enthusiastic I become. I've stopped caring about new products for a while already. So don't expect a sudden explosion of audio posts anytime soon.

For a while I've been considering giving the Anime part its own blog. But since this blog is currently on life-support, I might as well use it to resume talking about Anime stuff. So... yup, I'm going to break the unwritten rule of not talking about Anime.

And yes, expect an Anime post soon. Actually, expect a series.