Crossed Wires
I started typing this out in Word, and then it got long, so probably that one's going on the Big Blog, but just because this is a crossing of the nerdy streams that absolutely delights me, have the short version here:
I have not been in a band in a long time, and there's stuff I've forgotten.
I found my passive DI box today, which I used for my bass guitar.
I could not remember how this fucking thing worked or what it was supposed to do. Attenuating switches. Filter switches. Input: 1/4" jack. Output: balanced XLR. Line thru: 1/4". what the fuck?!
Before googling it, I allowed myself a sigh of embarrassment, because I did know all this at some point in my life, it's just that when the info goes into long-term storage in my ADHD brain, figuring out where it is and digging it free is like traipsing into the junk yard with a metal detector.
Translation of that metaphor: a lot of things are going to go PING! and I fkn guarantee you that none of those things will be the droids you are looking for
except godfuckingdammit the droids would set off a metal detector, look, don't examine this analogy too closely, okay.
where was I?
oh yeah, that's right.
(yes, I am abusing bullet points, but it turns out that they just let fucken anyone use bullet points these days, there's not even a fucking license or anything, how wild is that?! Anyways, no one can stop me, suffer in ya jocks.)
My memory wasn't helping, so I googled the DI Box, and read the quick summary of what it's meant to do, and that process is more like some sleek futuristic pattern matching magnet technology, because it was like it was summoning the existing knowledge (which I had stashed and which was inaccessible. Bad sectors. Defragmentation needed) back into my brain.
(if you have personal and extensive experience of defragmentation: congratulations. You are old, and welcome on my porch. Rocking chair not provided. BYO shotgun.)
Quick summary: musical instruments (such as bass guitars) put out the kind of signal that is too messy and unbalanced for a mixing desk, which requires a gentler and more standardised touch. So, you run your bass patch lead through a DI box, which filters and (effectively) standardises that signal, and funnels it out to the mixing desk in a more manageable form.
Not only does this wreak less overall havoc, but it means that you can deal with the instruments and the vocal mics (and so on) on an even playing field (or at least, you can try to standardise everything else against the fucking drumkit-- no, do not ask).
The "line thru" jack is to carry out the un-filtered signal directly to your bass amp, because the bass amp can handle it as an independent Gigantic Noise Machine.
So. Why did I start giggling while reading this? Because I'm a diver. More specifically, I'm a professional assistant dive instructor.
(technically. I don't actually instruct. I'm qualified to instruct, assistively (so to speak), but I like guiding just fine, thanks. I get to give newbies handy hints and help them out and point out amazing marine life, but we get veterans as well; they're all qualified divers, though, so I do not have to actively supervise anyone at all times, and I do not usually have to carry anyone's gear, or dive in a pool.)
And I thought... the DI Box is a fucking first stage regulator, isn't it.
Like I'm not even kidding with this analogy, it's fucking perfect. The first stage regulator attaches to your tank valve. It wrangles the pressure of the air coming out of your tank (which is probably about 220 bar or 3200 psi to start with, and drops steadily throughout the dive as you breathe your way through it), wrestling it down to a much more chill 10 bar / 150 psi or something in that neighbourhood, and dumps this more amiably-managed air into the low pressure ports. Those hoses connect to your BC inflator (uh, BC = "floaty jacket"), your dry suit inflator if you have one, and your second stage regulators.
The second stage regulators are the ones you breathe from, but easier to say that they're demand valves. The pressure of that air is pretty much dictated by how hard you breathe in.
Here's the other thing, right: there's even a "Line Thru". Yessiree, you got that high pressure port for hooking up the ol' Submersible Pressure Gauge (SPG), because that thing needs the STRAIGHT SIGNAL, unfiltered, unbalanced, unaltered, because... that's the thing that tells you how much air is left in your tank, in terms of pressure. You... really don't wanna regulate that.
This analogy does suggest that my SPG is basically like my old Behringer quad box (approx 60kg), except a good deal fucking lighter, much easier to get up two flights of stairs to our flat at the time, and much less inclined to get covered in cat hair.
(seriously the guy at the Music Swop Shop took my amp, looked it over, and said, "You have a cat, don't you?" because - for those who don't know - many amps are basically covered in scratchy carpet.)
(for anyone who doesn't know: yes, "Swop" is deliberately spelled with an "O", it's not a typo, don't @ me.)
Anyways, that was my anecdote, split into several anecdotes, and I can hear someone forming a Bullet Point Licensing Committee Advisory Group even as I type this, so I better skedaddle before I can be prosecuted for my crimes against formatting or narrative. Fortunately the sort of people who would be interested in that are not the sort of people who skip straight to "angry mob" -- I mean they get there eventually, but I have some lead time.
(there is a reason I called this thing "Anecdote Machine". You were warned.)
...okay but seriously the analogy is fucking perfect it's like the entirety of engineering as a concept - from maritime and scuba across to audio tech to computer and software - is just pretty much about trying to translate one type of energy into another so that one gadget will talk to another gadget and nobody gets blown up or set on fire.
oh shit. that's actually what engineering is, isn't it? you know there are some course guides that could have been a lot shorter, on reflection.
[edit: forgot to mention that the first stage actually drops the pressure from your tank a whole lot, actually, so anyways I have fixed that now...]
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