WEBVTT Kind: captions Language: en 00:00:00.000 --> 00:00:05.180 Our modern world essentially runs on fiber optic communication technology. 00:00:05.180 --> 00:00:09.620 On our increasingly connected planet, nearly everything we do from making a phone call, 00:00:09.620 --> 00:00:14.160 to checking our bank account balance, to yelling at computers to tell them to turn the lights off, 00:00:14.160 --> 00:00:19.460 to watching this very video almost certainly relied, at some point, on turning your voice, 00:00:19.460 --> 00:00:25.020 or input, or the data making this image into incredibly brief, incredibly fast pulses of light, 00:00:25.020 --> 00:00:29.940 firing that light with *A LASER* down a glass pipe, and counting the pulses 00:00:29.940 --> 00:00:31.490 on the other end. 00:00:31.490 --> 00:00:35.900 And probably doing that a whole bunch of times over potentially thousands of kilometers, 00:00:35.900 --> 00:00:37.830 nearly instantaneously. 00:00:37.830 --> 00:00:43.230 And yet, in the consumer space, fiber optics are almost nowhere to be found. 00:00:43.230 --> 00:00:47.680 We send digital video data over these complicated cables with upwards of a dozen little strands 00:00:47.680 --> 00:00:49.300 of copper inside them. 00:00:49.300 --> 00:00:53.420 Networking equipment in homes and businesses still uses Ethernet, twisted pairs of copper 00:00:53.430 --> 00:00:57.550 wire that need to be made more precisely with higher tolerances each time we want 00:00:57.550 --> 00:01:00.180 to push the speed up another order of magnitude. 00:01:00.180 --> 00:01:05.150 Really, we just haven’t seemed to find a place for fiber optics aside from piping the 00:01:05.150 --> 00:01:10.500 internet into your home or business, and even then that’s not exactly common. 00:01:11.360 --> 00:01:15.740 Except there was that one time Toshiba decided to connect CD players to amplifiers 00:01:15.740 --> 00:01:18.080 with fiber optics in 1983. 00:01:18.080 --> 00:01:22.480 Yes, although fiber optics may seem like the upper echelon of communications technology 00:01:22.780 --> 00:01:25.260 (and in fact kinda are) 00:01:25.260 --> 00:01:30.320 there has been one consumer-grade fiber optic standard floating around since the early ‘80s. 00:01:30.320 --> 00:01:33.760 That would be TOSLINK, which is a shortening of Toshiba Link. 00:01:33.770 --> 00:01:38.940 In this video, we’re going to learn a little bit about this surprisingly old optical standard. 00:01:38.940 --> 00:01:41.150 Ahh, the compact disc. 00:01:41.150 --> 00:01:45.850 What a beautifully engineered medium for storing uncompressed digital sound. 00:01:45.850 --> 00:01:50.400 As you likely know, these things store data in millions of little pits and lands, and 00:01:50.400 --> 00:01:55.020 when you shine a focused laser on those bumpy bits, the varying depth causes destructive 00:01:55.020 --> 00:01:59.760 interference and results in a reflected beam that flashes light and dark, representing 00:01:59.760 --> 00:02:01.530 ones and zeroes. 00:02:01.530 --> 00:02:06.350 Note that a pit doesn’t mean 1 and a land means 0, rather the transition from pit to 00:02:06.350 --> 00:02:11.440 land OR land to pit means 1, and a period of no change means 0. 00:02:11.440 --> 00:02:17.520 A CD player has to do a fair bit of processing before it can turn that raw data stream into sound. 00:02:17.520 --> 00:02:21.440 First it has to translate the eight-to-fourteen modulation of the pits and lands to reveal 00:02:21.450 --> 00:02:26.130 8 bit words, then it has to parse the various signalling within that datastream for things 00:02:26.130 --> 00:02:30.390 like track and time markers, and finally it has to work through the cross-interleaved 00:02:30.390 --> 00:02:36.190 Reed-Solomon coding to actually get the individual samples that make up digital sound. 00:02:36.190 --> 00:02:40.750 Once we’re at that step, we can send those decoded samples to a DAC in order to be turned 00:02:40.750 --> 00:02:45.410 into electrical impulses that will drive headphones or loudspeakers to impart mechanical impulses 00:02:45.410 --> 00:02:48.520 into the air that we hear as sound. 00:02:48.520 --> 00:02:52.680 If you’d like to learn more about the compact disc and how digital sound works, you can 00:02:52.690 --> 00:02:54.860 check out these previous videos of mine. 00:02:54.860 --> 00:02:58.430 Now without a DAC, we can’t turn those samples into sound. 00:02:58.430 --> 00:03:04.380 Since that’s the primary goal of a CD player, the CD player itself contains a DAC, and generates 00:03:04.380 --> 00:03:11.030 a line level analog audio signal to be sent to an amplifier over garden variety RCA cables. 00:03:11.030 --> 00:03:15.940 And for almost all intents and purposes, this is perfectly fine. 00:03:15.940 --> 00:03:20.180 Unless you cross the line into audiophile territory, you are probably delighted by the 00:03:20.190 --> 00:03:23.260 sound coming from these two little jacks. 00:03:23.260 --> 00:03:26.959 And so, for most of us, that’s the end of the story. 00:03:26.959 --> 00:03:32.030 But the act of playing a CD is the very last step in the life cycle of producing a sound 00:03:32.030 --> 00:03:33.760 recording on compact disc. 00:03:33.760 --> 00:03:38.220 In the studio, digital tape machines are creating digital recordings from microphones or other 00:03:38.230 --> 00:03:43.599 analog sources, and various editing equipment needs to access those recordings to be manipulated 00:03:43.600 --> 00:03:46.460 and eventually mastered into a compact disc. 00:03:46.460 --> 00:03:50.300 All of this is different today but just pretend like it’s 1985, OK, everyone’s doing it anyway. 00:03:50.300 --> 00:03:54.980 Knowing that there’d need to be some standard way to move digital audio streams around, 00:03:54.980 --> 00:04:00.330 Sony and Philips (the co-creators of the Compact Disc standard) developed S/PDIF, 00:04:00.330 --> 00:04:04.120 which is often pronounced “spidiff” because, let’s face it, that’s more fun. 00:04:04.120 --> 00:04:08.620 S/PDIF stands for Sony/Philips Digital Interconnect Format, or you might also see 00:04:08.620 --> 00:04:10.720 Sony/Philips Digital InterFace. 00:04:10.720 --> 00:04:14.940 When Sony and Philips hammered out the details on S/PDIF, they were using standard coaxial 00:04:14.940 --> 00:04:20.859 audio cables like these to send the digital data over garden variety copper wires. 00:04:20.859 --> 00:04:22.039 And that worked fine! 00:04:22.039 --> 00:04:23.610 No one was complaining. 00:04:23.610 --> 00:04:28.749 But then, Toshiba got into the CD player business, and they wanted to be able to send the raw 00:04:28.749 --> 00:04:33.629 digital sound data recovered from the CD separately to an amplifier, letting the amplifier’s 00:04:33.629 --> 00:04:39.210 built-in DAC do the digital to analog conversion, potentially reducing noise and interference. 00:04:39.210 --> 00:04:40.210 So they did. 00:04:40.210 --> 00:04:45.440 But, someone at Toshiba was apparently dissatisfied with the ordinary nature of RCA cables. 00:04:45.440 --> 00:04:47.120 [in a very over-the-top fashion] Pfft, it’s the future! 00:04:47.129 --> 00:04:52.960 We’re using lasers to read sound from these miraculously small polycarbonate discs, and 00:04:52.960 --> 00:04:58.480 YOU expect US to convey the data they contain using WIRES? 00:04:58.480 --> 00:05:02.140 What kind of technologically regressive firm do you think this is? 00:05:02.150 --> 00:05:03.770 We are TOSHIBA! 00:05:03.770 --> 00:05:06.270 We MAKE the future! 00:05:06.270 --> 00:05:07.379 And so they did. 00:05:07.379 --> 00:05:10.439 And really, what they did isn’t all that remarkable. 00:05:10.439 --> 00:05:14.849 See, sending S/PDIF signals over copper wire simply involved having a voltage repeatedly 00:05:14.849 --> 00:05:16.479 switch from high to low. 00:05:16.479 --> 00:05:21.449 S/PDIF uses biphase mark code, also known as Differential Manchester encoding, to make 00:05:21.449 --> 00:05:25.419 the signal’s clock part of the datastream itself, but now we’re getting into specifics 00:05:25.419 --> 00:05:28.240 that don’t really matter because of this fun little truth nugget; 00:05:28.240 --> 00:05:32.210 TOSLINK transmits the same exact S/PDIF signals. 00:05:32.210 --> 00:05:32.940 Yep. 00:05:32.940 --> 00:05:38.219 TOSLINK is nothing more than a fancier way to send a S/PDIF datastream to another device. 00:05:38.219 --> 00:05:42.509 Rather than using a wire and pulsing a voltage through it, TOSLINK uses optical fiber and 00:05:42.509 --> 00:05:43.940 a pulsing light. 00:05:43.940 --> 00:05:47.790 Of course, the sending device had to run a pulsing voltage through an LED to create that 00:05:47.790 --> 00:05:51.289 pulsing light, and then again the receiving end has to use a photodiode to turn that pulsing 00:05:51.289 --> 00:05:54.920 light into a pulsing voltage, so when we get right down to it is there really a difference at all? 00:05:54.920 --> 00:05:58.520 Well, yes, but, kinda, no... 00:05:58.520 --> 00:06:00.240 And also, it’s complicated. 00:06:00.240 --> 00:06:04.020 Firstly, I don’t want to sound overly harsh here towards TOSLINK. 00:06:04.029 --> 00:06:08.159 Sending a signal through optical fiber is not only objectively cooler, but does have 00:06:08.159 --> 00:06:10.039 some advantages. 00:06:10.039 --> 00:06:11.689 Though even that’s debatable. 00:06:11.689 --> 00:06:16.300 And secondly, while TOSLINK is indeed a fiber optic communication standard, it is in no 00:06:16.300 --> 00:06:21.520 way comparable to the fiber optic networking equipment that makes up the backbone of the internet. 00:06:21.520 --> 00:06:26.440 So while TOSLINK may not have much to brag about compared to a simple coaxial S/PDIF connection 00:06:26.440 --> 00:06:29.270 this isn’t to say fiber optics aren’t important. 00:06:29.270 --> 00:06:30.740 But back to TOSLINK. 00:06:30.740 --> 00:06:35.560 One of the stranger things about it is that its history seems almost entirely unknown. 00:06:35.560 --> 00:06:39.189 I’ve been looking for some sort of patent related to it but haven’t had any luck, 00:06:39.189 --> 00:06:44.039 and even if Toshiba did patent it, it looks like they just let it out into the wild. 00:06:44.039 --> 00:06:48.759 It was fairly common on high-end CD players by the late 1980’s, and in 1987 it was referred 00:06:48.759 --> 00:06:53.589 to as an ad hoc standard by Digital Audio and Compact Disc Review. 00:06:53.589 --> 00:06:57.789 So it looks like, though Toshiba may have created it (and they appear to have the trademark 00:06:57.789 --> 00:07:02.629 on the word TOSLINK), they let pretty much anyone who wanted to use it, use it. 00:07:02.629 --> 00:07:03.919 It just sorta happened. 00:07:03.919 --> 00:07:08.680 Indeed, the TOSLINK connector and cable specifications were adopted by the Electronic Industries 00:07:08.680 --> 00:07:13.590 Association of Japan as EIAJ RC-5720 00:07:13.590 --> 00:07:17.300 The physical bits of the TOSLINK standard are actually pretty darn simple. 00:07:17.300 --> 00:07:21.880 Take a look at an optical audio out port and you’ll see it glows with the red light of an LED. 00:07:21.880 --> 00:07:26.860 Some people think TOSLINK uses lasers, but it’s just an LED, it’s much cheaper and 00:07:26.870 --> 00:07:28.129 works fine. 00:07:28.129 --> 00:07:32.099 Taking a look inside the device reveals that, well, there’s not a lot going on behind 00:07:32.099 --> 00:07:33.099 the scenes either. 00:07:33.100 --> 00:07:37.460 It’s just a molded bit of plastic to hold onto the connector and align the tip of the cable 00:07:37.460 --> 00:07:38.540 with the LED. 00:07:38.540 --> 00:07:41.110 The cable itself isn’t really special, either. 00:07:41.110 --> 00:07:46.629 While some high-quality cables will use bundles of very thin glass strands, many are simple 00:07:46.629 --> 00:07:50.100 1mm plastic fibers that run from one end to the other. 00:07:50.100 --> 00:07:52.580 Pretty much just a strand of fishing line. 00:07:52.589 --> 00:07:56.129 You can see that the cable will pass light through it no matter how it loops around, 00:07:56.129 --> 00:08:00.300 though if you introduce an extreme kink, you can damage the cable. 00:08:00.300 --> 00:08:04.569 With it plugged into the back of this CD player, you can see that now the other end glows, 00:08:04.569 --> 00:08:07.520 ready to pump that pulsing light into another device. 00:08:07.520 --> 00:08:11.639 On the back of an A/V receiver or other sort of amplifier, you’ll see some other TOSLINK 00:08:11.639 --> 00:08:13.929 connections though these don’t glow. 00:08:13.929 --> 00:08:17.939 Well, some of them might if it’s also got a return out for something like a digital 00:08:17.939 --> 00:08:22.029 audio recorder or MiniDisc player or whatever, but if it’s the receiving end, it’s as 00:08:22.029 --> 00:08:24.520 dark as the future of Windows phone. 00:08:24.520 --> 00:08:28.620 Inside is a photodiode which will produce a voltage when it sees light, and thus will 00:08:28.629 --> 00:08:32.620 be able to reproduce the pattern of light pulses it receives as a pattern of voltage 00:08:32.620 --> 00:08:37.780 pulses to be processed, interpreted by a DAC and finally turned into sound. 00:08:37.780 --> 00:08:40.700 It wasn’t just CD players that used TOSLINK. 00:08:40.700 --> 00:08:41.870 Wait. 00:08:41.870 --> 00:08:43.900 I already mentioned MiniDisc. 00:08:43.900 --> 00:08:44.620 Pretend I didn’t. 00:08:44.620 --> 00:08:45.480 Rewrites are hard. 00:08:45.480 --> 00:08:50.820 As more digital formats appeared on the scene, like Digital Audio Tape in 1987, it was common 00:08:50.820 --> 00:08:54.800 to see TOSLINK inputs and outputs on mid-to-high-end equipment. 00:08:54.800 --> 00:08:55.720 Fun fact! 00:08:55.720 --> 00:09:00.420 The advent of consumer digital recording really freaked out the recording industry, as now 00:09:00.420 --> 00:09:06.820 it was possible to create bit-for-bit perfect copies of a CD onto a digital audio tape cartridge. 00:09:06.820 --> 00:09:11.560 While TOSLINK wasn’t the only way to accomplish this, it was pretty widely supported by then 00:09:11.560 --> 00:09:16.160 and we may have this little cable to at least partially thank for the Audio Home Recording 00:09:16.160 --> 00:09:21.460 Act of 1992, the later Digital Millennium Copyright Act, and the subsequent DRM schemes 00:09:21.460 --> 00:09:23.970 that would be cooked up in the decades to come. 00:09:23.970 --> 00:09:25.730 [a large crowd chants in unison] Thanks, Toshiba! 00:09:25.730 --> 00:09:29.660 One of the more interesting things I ran across was a seemingly needless design detail that 00:09:29.660 --> 00:09:33.040 hints at a never-realized upgrade to TOSLINK. 00:09:33.040 --> 00:09:39.440 See, the connector itself is keyed, meaning it can only be inserted with one orientation. 00:09:39.450 --> 00:09:45.440 This isn’t necessary given that the optical fiber itself is centered, and there’s only one of them. 00:09:45.440 --> 00:09:47.640 I honestly never even thought about this. 00:09:47.640 --> 00:09:52.510 If, however, there were two fibers in the same cable, say one for transmitting data 00:09:52.510 --> 00:09:56.760 and another for receiving, there would need to be a way to ensure the fibers in this two-way 00:09:56.760 --> 00:09:59.680 cable are correctly aligned with the connector. 00:09:59.680 --> 00:10:04.780 It’s possible that the TOSLINK connector was keyed for just such a cable design, though 00:10:04.780 --> 00:10:06.500 this never came to fruition. 00:10:06.500 --> 00:10:07.500 Cool. 00:10:07.500 --> 00:10:11.260 So TOSLINK is a simple way to turn S/PDIF into light, push it through a pipe, and then turn 00:10:11.260 --> 00:10:13.320 light back into S/PDIF. 00:10:13.860 --> 00:10:16.620 But, um, why? 00:10:16.620 --> 00:10:19.900 Well, here’s where things start to seem a little superfluous. 00:10:19.900 --> 00:10:24.450 One of the key advantages of using an optical fiber to send data is that it’s not subject 00:10:24.450 --> 00:10:26.380 to electromagnetic interference. 00:10:26.380 --> 00:10:30.980 Normal audio cables like these can pick up humming or whining or any other sort of noise 00:10:30.990 --> 00:10:32.870 because they act like antennae. 00:10:32.870 --> 00:10:37.360 But… if we’re in the digital realm, what difference does that make? 00:10:37.360 --> 00:10:42.580 Sure, a coaxial cable carrying a S/PDIF signal can pick up noise, but unless that noise gets 00:10:42.580 --> 00:10:47.640 so phenomenally bad that it somehow overpowers the very powerful and not-at-all ambiguous 00:10:47.640 --> 00:10:51.740 high-low-high-low pattern the cable carries, it doesn’t matter. 00:10:51.740 --> 00:10:56.500 Analog noise in a digital signal doesn’t come out in the processed result. 00:10:56.500 --> 00:10:59.120 This has always seemed more than a little weird to me. 00:10:59.120 --> 00:11:03.070 TOSLINK’s signature advantage, that it’s immune to electromagnetic interference, would 00:11:03.070 --> 00:11:07.880 only really be a selling point if it were transmitting analog signals. 00:11:07.880 --> 00:11:08.880 But it isn’t. 00:11:08.880 --> 00:11:12.740 For the most part, either a digital signal gets through, or it doesn’t. 00:11:12.740 --> 00:11:16.720 Until the signal gets so bad that the receiver can’t piece it together correctly, it will 00:11:16.730 --> 00:11:19.070 sound exactly the same. 00:11:19.070 --> 00:11:22.500 And once problems do show up, it’s gonna get glitchy 00:11:22.500 --> 00:11:24.950 [audio defects begin to appear] or the signal will just drop out. 00:11:24.950 --> 00:11:27.050 It’s not gonna sound worse. 00:11:27.050 --> 00:11:29.230 It won’t sound right at all. 00:11:29.230 --> 00:11:33.260 So choosing TOSLINK over coaxial because it is impervious to RF interference or other 00:11:33.260 --> 00:11:38.200 electrical noise is, well, I’d argue rather uninformed. 00:11:38.200 --> 00:11:41.740 Your amplifier’s circuitry doesn’t care how it’s getting that data. 00:11:41.740 --> 00:11:46.580 And once it gets to the DAC, we’re well past the point where cables could make a difference. 00:11:46.580 --> 00:11:51.000 Now it can be argued that having your audio devices entirely electrically isolated from 00:11:51.000 --> 00:11:55.260 one another could be advantageous because it prevents freak occurrences like a huge 00:11:55.260 --> 00:11:58.880 electrical spike through your RCA jacks cooking a chip on your amp or something 00:11:58.880 --> 00:12:03.900 really unlikely like that, though if you’re really worried about electrical isolation 00:12:03.910 --> 00:12:08.960 for sound quality purposes, good luck avoiding the building’s electrical wiring 00:12:08.960 --> 00:12:11.100 they’re eventually gonna share. 00:12:11.100 --> 00:12:14.400 And then, well, TOSLINK actually has a lot of disadvantages. 00:12:14.410 --> 00:12:18.760 The most significant practical issue is that the longer the cable gets, the harder it is 00:12:18.760 --> 00:12:20.980 for light to reach the other end. 00:12:20.980 --> 00:12:26.310 Remember, this is largely a consumer standard, so even the most premium cables aren’t anything 00:12:26.310 --> 00:12:31.010 near optically pure and the longer they get, the more they reduce the amount of light that 00:12:31.010 --> 00:12:32.440 gets through. 00:12:32.440 --> 00:12:36.060 Add to that the fact that it’s only got a weedy little LED lighting the whole thing 00:12:36.070 --> 00:12:39.700 up, and you get a maximum cable length of 5 meters. 00:12:39.700 --> 00:12:45.300 In practice this can be and is regularly exceeded, especially with the brighter LEDs and with more 00:12:45.300 --> 00:12:50.220 sensitive photodiodes of more modern equipment, but with a coaxial cable you can go a lot 00:12:50.220 --> 00:12:52.400 farther before issues crop up. 00:12:52.400 --> 00:12:57.480 Now I don’t want to get too far into comparing TOSLINK to a coaxial S/PDIF connection, because 00:12:57.480 --> 00:13:02.390 that means getting into incredibly nitpicky details like clock jitter that you shouldn’t 00:13:02.390 --> 00:13:06.110 even look up because trust me it will just make you question your sanity. 00:13:06.110 --> 00:13:08.920 So instead, let’s talk about Mini-TOSLINK! 00:13:08.920 --> 00:13:13.160 Since the only part that actually interfaces with the LED and photodiode is this little 00:13:13.170 --> 00:13:18.170 nib, the mini-TOSLINK connector was created to allow optical audio connections in the 00:13:18.170 --> 00:13:24.460 same form factor as a 3.5mm audio jack, and indeed to combine optical audio and analog 00:13:24.460 --> 00:13:27.100 audio into a single port. 00:13:27.100 --> 00:13:31.630 This by the way is perhaps the greatest proof that they keying in the standard TOSLINK connector 00:13:31.630 --> 00:13:35.690 was completely unnecessary unless they had future plans. 00:13:35.690 --> 00:13:40.510 The TOSLINK part of this is just an itty bit longer than a normal audio jack, just to make 00:13:40.510 --> 00:13:45.000 sure that when you plug in headphones or whatever you don’t poke the LED or photodiode. 00:13:45.000 --> 00:13:45.960 Fun fact! 00:13:45.960 --> 00:13:50.960 I didn’t know this was a thing until I was messing about with my Chromecast Audio, unplugged 00:13:50.960 --> 00:13:55.020 the audio cable from it, and the hole started glowing. 00:13:55.020 --> 00:14:00.860 I kid you not, I did not know Mini-TOSLINK was a thing, and I learned about it by accident. 00:14:00.860 --> 00:14:04.560 I don’t know exactly how common it is in the grand scheme of things, but it allowed 00:14:04.560 --> 00:14:09.620 portable devices like this MiniDisc Walkman to record from an optical source. 00:14:09.620 --> 00:14:10.860 Neat. 00:14:10.920 --> 00:14:14.060 Apparently it was found in some laptops and other random junk. 00:14:15.040 --> 00:14:19.780 I hope it wasn’t, like, super common and I’ve just missed this until 2016 or whatever. 00:14:19.780 --> 00:14:20.540 By the way. 00:14:20.540 --> 00:14:24.300 If you go to Amazon and search “toslink cable” you’ll find that some of the more 00:14:24.300 --> 00:14:27.180 popular options feature gold-plated connectors. 00:14:27.580 --> 00:14:29.699 [exasperated sigh] 00:14:29.699 --> 00:14:33.660 So far, optical audio connections have really withstood the test of time. 00:14:33.660 --> 00:14:39.210 It’s pretty impressive that a digital standard introduced in 1983 is still quite common in 00:14:39.210 --> 00:14:41.520 consumer audio visual equipment. 00:14:41.520 --> 00:14:47.120 Loads of new TVs feature an optical audio out, as do game consoles, Blu-Ray players, 00:14:47.120 --> 00:14:49.200 and even some streaming boxes. 00:14:49.200 --> 00:14:53.760 Recently, that’s started changing for reasons we’ll get into, but on the whole it’s 00:14:53.779 --> 00:14:56.380 still a pretty common sight in 2019. 00:14:56.380 --> 00:15:00.590 A large part of why it’s still so common is that in addition to uncompressed stereo 00:15:00.590 --> 00:15:07.279 PCM audio, TOSLINK also supported compressed 5.1 or 7.1 surround sound using Dolby Digital 00:15:07.279 --> 00:15:08.900 or DTS. 00:15:08.900 --> 00:15:12.960 Since loads of A/V receivers going back to the ‘90s will still be able to process at 00:15:12.960 --> 00:15:18.300 least some of the datastreams coming from a Blu-ray player or smart TV, it’s been 00:15:18.300 --> 00:15:19.570 remarkably future-proof. 00:15:19.570 --> 00:15:25.350 Also of note is that the physical specifications of TOSLINK were borrowed in the ADAT Lightpipe, 00:15:25.350 --> 00:15:27.450 or ADAT Optical Interface. 00:15:27.450 --> 00:15:32.420 This professional standard carries up to 8 channels of uncompressed PCM audio using the 00:15:32.420 --> 00:15:38.000 same hardware as garden variety TOSLINK connectors and cables, though this high-bandwidth signal 00:15:38.000 --> 00:15:41.690 is entirely incompatible with our old friend S/PDIF. 00:15:41.690 --> 00:15:45.070 So then, why is TOSLINK apparently on its way out? 00:15:45.070 --> 00:15:49.490 Well… because of the same thing I said was an advantage a few moments ago. 00:15:49.490 --> 00:15:51.680 It’s not been updated. 00:15:51.680 --> 00:15:53.279 Like, at all. 00:15:53.279 --> 00:15:58.820 One of the things Blu-ray brought us was uncompressed surround sound formats like Dolby TrueHD, 00:15:58.820 --> 00:16:01.161 and TOSLINK doesn’t have the bandwidth to support that. 00:16:01.161 --> 00:16:02.980 [angry yelling off-screen] YOU JUST SAID ADAT Lightpipe 00:16:02.980 --> 00:16:05.400 could carry 8 channels of PCM audio! 00:16:05.740 --> 00:16:07.420 You’re right, I did. 00:16:07.420 --> 00:16:10.600 But that’s not actually TOSLINK or S/PDIF. 00:16:10.600 --> 00:16:12.540 It just uses the same cable and connectors. 00:16:12.540 --> 00:16:13.240 [offscreen person mutters angrily] 00:16:13.240 --> 00:16:17.300 See, it would be relatively easy to just make the LED go blinky blinky a little faster and 00:16:17.300 --> 00:16:20.760 thus increase the bitrate of the data coming through the cable. 00:16:20.760 --> 00:16:26.480 But that means creating a new standard to be agreed upon by all the manufacturers out there. 00:16:26.480 --> 00:16:29.100 And, uh, that can be difficult! 00:16:29.110 --> 00:16:33.520 See, I can connect this brand new television to this A/V receiver from the ‘90s over 00:16:33.520 --> 00:16:37.750 TOSLINK precisely because the standard hasn’t really ever changed. 00:16:37.750 --> 00:16:42.610 If TOSLINK were updated, at the very least I’d need to tell the TV to downgrade its 00:16:42.610 --> 00:16:47.940 output to match this receiver’s expected input, and that can get messy fast. 00:16:47.940 --> 00:16:50.920 Remember, this is one-way communication. 00:16:50.920 --> 00:16:53.480 Easier to just never change it up, ya know? 00:16:53.480 --> 00:16:56.840 And then there’s this other thing called HDMI. 00:16:56.840 --> 00:17:01.140 Yeah, the Handy-Dandy Movie Input not only transmits digital video at a bitrate that 00:17:01.140 --> 00:17:05.679 will put your CD player to shame, but it also transmits digital audio at bitrates that will 00:17:05.679 --> 00:17:07.879 put your CD player to shame. 00:17:07.879 --> 00:17:09.089 Poor CD player. 00:17:09.089 --> 00:17:10.730 You’re doing alright. 00:17:10.730 --> 00:17:18.260 Since the very first HDMI version 1.0, debuting in December 2002, uncompressed 8 channel, 00:17:18.260 --> 00:17:23.280 192 kilohertz, 24 bit PCM audio was supported. 00:17:23.280 --> 00:17:25.420 That’s like way more bits! 00:17:25.429 --> 00:17:29.649 With all that bandwidth, high-resolution sound is no problem at all. 00:17:29.649 --> 00:17:36.100 S/PDIF, and thus TOSLINK, sorta became obsolete once Blu-ray, and even HD-DVD, appeared on 00:17:36.100 --> 00:17:39.049 the scene offering lossless surround sound. 00:17:39.049 --> 00:17:41.950 HDMI could carry those signals no problem. 00:17:41.950 --> 00:17:49.380 Oh and HDMI 2.0 introduced 32 channel audio, so we're fine now. 00:17:49.380 --> 00:17:56.120 ALSO, in 2009 HDMI 1.4 introduced the audio-return channel, that’s why one of the HDMI inputs 00:17:56.130 --> 00:17:58.750 on your TV is labeled ARC. 00:17:58.750 --> 00:18:03.869 This sends audio back through the HDMI cable to enable your soundbar or home theater system 00:18:03.869 --> 00:18:08.210 to receive the audio that your TV itself is producing, such as when streaming video on 00:18:08.210 --> 00:18:13.020 a Smart TV or simply receiving over-the-air broadcast television. 00:18:13.020 --> 00:18:13.520 Yeah. 00:18:13.520 --> 00:18:18.140 HDMI has superseded TOSLINK on all fronts in the home theater space. 00:18:18.140 --> 00:18:23.860 As more sound bars and A/V receivers support the audio-return channel, TOSLINK increasingly 00:18:23.869 --> 00:18:26.639 finds itself in the legacy category. 00:18:26.640 --> 00:18:29.800 Which is still, just kinda weird! 00:18:29.800 --> 00:18:35.040 Fiber-optics are capable of some insane bandwidths, and while TOSLINK hails from the age of 10 00:18:35.040 --> 00:18:40.760 megabyte hard drives, you’d think that we’d have seen more fiber optic standards in the home. 00:18:40.760 --> 00:18:45.320 In the next video, we’ll explore why fiber optics have remained little more than a novelty 00:18:45.320 --> 00:18:49.600 in the consumer space, and discuss whether any of our current everyday technologies could 00:18:49.600 --> 00:18:52.139 perhaps be better served with fiber optics. 00:18:52.139 --> 00:18:53.260 Thanks for watching. 00:18:53.260 --> 00:18:57.140 I hope you found this video to be as enlightening as it is digital. 00:18:57.860 --> 00:19:00.400 That is terrible. 00:19:00.400 --> 00:19:01.120 And yet. 00:19:01.120 --> 00:19:02.060 I still said it. 00:19:02.060 --> 00:19:03.380 Worse, I wrote it! 00:19:03.400 --> 00:19:04.900 I even wrote these words! 00:19:04.900 --> 00:19:06.009 How silly. 00:19:06.009 --> 00:19:10.210 But not as silly as selling TOSLINK cables with gold plated connectors and claiming that 00:19:10.210 --> 00:19:12.320 makes a superior connection! 00:19:12.320 --> 00:19:17.690 Anyway, I still think TOSLINK is pretty neat and even futuristic, even though it’s pushing 00:19:17.690 --> 00:19:19.399 40 years old now. 00:19:19.399 --> 00:19:23.139 As always, thank you to everyone who supports this channel through Patreon, particularly 00:19:23.139 --> 00:19:25.990 the fine folks you see scrolling up your screen. 00:19:25.990 --> 00:19:30.100 Contributions from viewers like you make this channel sustainable and I owe you my thanks 00:19:30.100 --> 00:19:31.570 and appreciation. 00:19:31.570 --> 00:19:34.440 If you’d like to join these awesome people in supporting the channel with a pledge of 00:19:34.440 --> 00:19:38.279 your own, you can find a link to my Patreon page in the description. 00:19:38.280 --> 00:19:40.800 Thanks for your consideration, and I’ll see you next time! 00:19:41.660 --> 00:19:44.020 ♫ optically smooth jazz ♫ 00:19:45.660 --> 00:19:47.279 ...communication technology. 00:19:47.280 --> 00:19:52.000 On our increasingly connected planet, nearly everything we do from making a phone ca… 00:19:53.580 --> 00:19:56.140 I didn’t get very far! 00:19:56.140 --> 00:19:57.940 Since the only wat that, whoops? 00:19:59.460 --> 00:20:03.059 Uncompressed digital surround formats. 00:20:03.059 --> 00:20:04.640 That line is wrong!!! 00:20:04.640 --> 00:20:05.640 Oh no!!!!! 00:20:05.840 --> 00:20:10.480 That take might have been fine, but there were some weird bits. 00:20:10.480 --> 00:20:13.780 Also of note is that the physical specifications of TOS… 00:20:13.780 --> 00:20:15.520 Whe.. *clears throat* 00:20:16.100 --> 00:20:17.700 Pairs of copper wire that need to be made 00:20:17.700 --> 00:20:20.640 more precisely and with higher tolerances euch… 00:20:20.640 --> 00:20:21.980 AUGH! 00:20:22.340 --> 00:20:26.860 We are on the second line, and recording is… 00:20:26.860 --> 00:20:28.620 [unintelligible]