WaterWaiver @ WaterWaiver @aussie.zone

I once met a person that never drank water, only soft drinks. It's not the

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2 yr. ago

(Not sure if my other comment got deleted successfully or not, so posting this next to it)

Sorry, I reacted to your second sentence without reading the rest. (I am Australian, I was a bit offended by reading "Australia had mandatory confiscation of ALL guns basically")

In Australia the gun buybacks were followed by decreases in gun violence. It's debated whether that was because of the gun buybacks or other policies, it's hard to be certain without two identical countries and A-B testing. Nonetheless: anything that makes guns and gun parts less available is likely to help and doesn't seem to have much in the way of disadvantages other than money. These days it's mostly through gun amnesties (not buybacks) so that problem is avoided.

I'm on a semi-static IP. It has never changed (3 years now) but might theoretically. An actual static ip is an extra $5/mon addon last I checked.

When I signed up I was on CGNAT (default for all new customers). I called them, explained why this didn't work for me and they changed me to a proper IPV4 address without any hassle.

Just for internet, or something more complicated? Also it looks like they're nuking their email service if you're using that.

I'm a bit lost sorry :/ Least cost routing for phonecalls? Or did you peer through them?

Thanks DHMO.

Several thoughts merged into one (pick any choose bits, not all or nothing):

• c/Auslocal <- replacing /c/Syd /c/Melb etc. General discussion
• c/AusInterestingNews <- "interestingNews" is probably better wording than "goodNews" as it might avoid some politics ending up there. Less drama for users & mods perhaps.
• c/Australia <- people posting politics will probably default to the general "Australia" regardless of what rules you try to put in. If you roll with that and intentionally keep it as a honeypot then it might be an easier solution for users and mods? ie don't try and move the politics out of /c/Australia, instead move everything else out into c/Interestingnews.

Have they tested this lignin+resin against a control of just resin? Does the lignin reinforcement add much in the way of advantages?

At the end of the day it's more resin than wood, so I think "transparent wood" is misleading. It's wood-reinforced resin.

Hiring: Low level guys.

Opportunities: Adventurer interactions. Loot. Rumours before the bigger places hear about them.

-- Dungeon management

What's the motivation of splitting things into Australia-general and Australia-politics? Is it to have a space that's less stressful than the other to read?

Purely for logging 3rd party maintenance for their internal market research purposes I'm sure :D

As well as everyone else's answer here about bias power: it could also just be because a 3-pin TRS are cheaper/easier to buy and get assembly tooling for than 2-pin TRS. Economies of scale.

(For a good example of this: 3-axis accelerometers are cheaper than 1-axis and 2-axis ones. Everyone wants 3-axis for mobile phones, drones, human inputs and the like. You're better off buying a 3-axis chip and ignoring the extra channels)

No. Modern FPGAs do not use any UV light or have any windows. For storage they use flash memory (same as what's used in MicroSD cards, USB sticks and SSDs). Some (most?) require you to provide this yourself externally.

Old EPROM (not EEPROM) storage had windows and needed UV to erase, but that's decades old. I'm not sure if FPGA was common nomenclature back then (PAL/GAL/CPLD were probably the market).

Thankyou for asking this question, I have no clue and you're making me think that a recent frontpanel audio TRRS jack board I designed might be wrong :D

There are two possible options I can see:

1. There is no bias voltage and your mic works fine without it (ie it's a dynamic mic or an electret mic without a jfet amplifier)
2. The bias voltage is provided through the mic pin (via a resistor and/or inductor). The mic then overlays AC onto this DC signal.

I cannot find any good references or info about mic bias and TRRS connectors :( Anyone else have any luck? Wikipedia says it's a standard referred to as "CTIA" or "AHJ" but those appear to be company names, not standard names.

My current headset uses a TRRS, but also provides an extension cable that splits into two 3.5mm TRS just like yours. I might probe it out and find out what it's doing (but that doesn't mean it's the right/universal solution).

"Cold" suggests you're thinking of balanced signalling. You don't have any balanced options with standard headphones and computer PC jacks, everything is unbalanced. Both the 4-connector (TRRS) and 2x3-connector (TRS) variants of your headphone connectors are unbalanced audio.

There might be a difference in crosstalk between the speaker and mic wires (ie signals going to your speakers leaking through the wire insulation and into the mic wires), but it should be inaudible if the cables and headset are designed correctly.

Sorry Jarfil if I'm being nitpicky :|

They don’t need to send the same signal inverted, just allow both cables to react in the same way to any interference (maintain the same impedance).

These are both the same thing, just viewed from different angles. Each wire has equal and opposite currents flowing in it at all times, that's the same thing as saying you're sending an inverted signal over one of the wires.

"phantom power" [...] "bias power"

Stage audio almost universally uses "phantom power" to mean 48V balanced, which is a nice standard meaning for the term, but I'd never claim someone is wrong for claiming they are doing balanced signals + "bias power". It'd raise an eyebrow (have they made a mistake? it's uncommon) but it's still reasonable, I don't think "bias power" specifically refers to only unbalanced configurations.

Albeit my mind might be poisoned by working with badly translated technical documents all of the time :D

You're describing balanced/differential signalling. This is used in stage or professional audio (typically over XLR connectors, but not always).

The 3.5mm TRS connectors that the OP has pictured are extremely unlikely to be using balanced signalling. If they did then they would not be compatible with the headphones jacks on computer motherboards or case fronts which follow the AC'97 or Intel HD Audio standards.

Without bias power, the sound itself needs to power the system, meaning any sound below some threshold will get “used up” by the mic and not transmitted

This is false. I suspect this myth came about because this is how magnetic audio tapes work (tape bias).

Dynamic microphones do not benefit from bias. They can tolerate a small amount but too much will burn them out (depending on their resistance & the voltage applied) or increase distortion (depending on the mechanical construction & how much the diaphragm is moved by the DC). Some dynamic mic units are built with capacitors in them to intentionally block bias voltages, preventing them from burning out.

I have never seen a datasheet or research paper showing improved dynamic mic performance due to DC offset. If it helped then a manufacturer would be recommending it in the datasheets (so they could claim better distortion & sensitivity specs).

Mics with in-built amplifier circuits require bias voltage to function. Many small "electret" modules contain jfet amps, you have to check the datasheet because they look identical to non-amplified versions on the outside. This is very common in small computer & headset mics. Some might work without bias, but they will sound poor because the amplifier circuit is not designed to work this way.

Condenser mics need some form of bias voltage to function at all. Electrets provide this themselves through some magic materials science that's similar to a battery that lasts for years/decades/centuries. The other types of condenser mic require you to apply an external bias voltage (aka "phantom power").

Magnetic audio tape suffers 'hysteresis' and nonlinearity which cause distortion of audio (especially quiet audio). Applying a bias voltage works around this problem. DC biases work, but high frequency AC ones are typically better.

I suspect the source of this myth is a confusion between the magnetics of tapes and the magnetics of dynamic mics. I think I recall a year 8/9 science class where I was taught that audio could be amplified slightly by putting a battery in series with a microphone and speaker. I failed to find any sources to support that at the time, but the teacher was adamant that this used to be a legitimate method. Perhaps if the coils were not glued properly in the speaker & mic? It was supposed to be a solution before the days of tube amplifiers but I think the true information turned into nonsense somewhere along the chain.

but… all real world materials have a resistance, capacitance, reactance and a resulting impedance, which need to be overcome for the signal to resemble the sound the membrane is picking up.

Resistance, capacitance and inductance are linear. They will affect all signals the same way, they will not only affect small signals.

To affect the small signals differently to the large signals you need nonlinear elements, like diodes and transistors. EDIT: there are also nonlinear capacitors and resistors, but they're from more exotic materials than what you find in standard headphone wires & mic designs.

Yeah not one mention of "I'll never forget you Princess"

Very pretty stuff. I particularly recommend Ken Shirriff's Reverse-engineering the mechanical Bendix Central Air Data Computer:

He goes into detail about how non-linear equations are implemented using shaped cam gears (and how such functions can be difference-encoded against linear forms). It's insane.

And because it’s analog, there is no quantisation, rounding errors, floating point errors.

Eh, I'd say that runout and stiction are their own demons with potentially more bias than those error types :) Not to mention temperature sensitivity -- hot days will give different answers to the equations!

Are FPGAs particularly suited to solving PDEs? I just did a search and there seem to be some papers discussing implementing various PDE solving algorithms on FPGAs, but I'm not sure if it's a task uniquely suited to them.