Twisted USB - Page 1
Forum section: electronics / beginners

author: Ogitek
author_rank: Regular Contributor
timestamp: January 12, 2024, 02:00:37 pm
content: According to baseline USB 2.0 specifications, the USB cable must have signal (green-white) wires as a twisted pair with 90 Ω differential impedance.What if you use one of the twisted pair as V+ or ground and the data in one of the original V+, ground wire (for sake of understanding it). Would the USB still work? If it would still work, how many speed decrease would it encounter? 50% 80%

author: wraper
author_rank: Unknown
timestamp: January 12, 2024, 02:05:05 pm
content: Quote from: Ogitek on January 12, 2024, 02:00:37 pmLow speed (1.5 mbps) devices like low end mice or keyboard most likely will work. Full speed (12mbps) YMMW, anything faster, no.QuoteThere would be not speed decrease but communication failure.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 12, 2024, 02:16:19 pm
content: Quote from: wraper on January 12, 2024, 02:05:05 pmThat means any serial port devices that has bps like 115,200 bps can still work? 115,200 bps being 0.1152 mbps only?Does this mean for serial port devices. Even a plain 4 wire stranded wire (without twisting) can make it run?QuoteWhat? you just said 1.5 mbps would still work, why communication failure?

author: wraper
author_rank: Unknown
timestamp: January 12, 2024, 02:21:36 pm
content: USB devices work at predetermined speed (USB LS, FS, HS mode), they don't adjust their speed depending on how well communication works.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 12, 2024, 02:24:20 pm
content: Quote from: wraper on January 12, 2024, 02:21:36 pmWhat do you mean? If the serial port is only 115,200 bps. then the USB to serial port converter would only be 115,200 bps, isn't it.Can you give some figures.

author: magic
author_rank: Super Contributor
timestamp: January 12, 2024, 02:28:38 pm
content: I once connected a high speed card reader to motherboard's USB pin header with some random 10-pin IDC cable, which I think was originally meant for audio panels. It worked.Like all dodgy stuff, you won't know for sure until you try.Quote from: Ogitek on January 12, 2024, 02:24:20 pmIt can be transmitting nothing and yet USB link bitrate is what it ishttps://duckduckgo.com/?q=USB+LS%2C+FS%2C+HS

author: Ogitek
author_rank: Regular Contributor
timestamp: January 12, 2024, 02:41:21 pm
content: Supposed you have an ADC module connected to USB 2.0. The ADC speed is much less than 480Mbps (speed of USB 2.0). And you use simple 4 stranded wire as USB cable, and the USB speed gets down to 1.5 mbps. Let's say the ADC only need 115,200 bps. It won't work?

author: dobsonr741
author_rank: Frequent Contributor
timestamp: January 12, 2024, 02:43:49 pm
content: Do I understand OP’s proposal right? Swapping the white-green with black-red pair.Given in the usual cables, even for high speed, they are exactly the same material/size, for cost saving, so it does not matter. Only the color changes.Where you start to see different wire size, tight twisting vs no twisting on power is on the USB-C and above. I did not yet see differentiation on the 4 wire cables. Or maybe I did not cut into enough cables?Bit rate: b/c the baud of a virtual com port is 115200, it does not mean the USB packets are using a lower bit rate. The bit rate is whatever the peripheral descriptor tells, low/full/high, during enumeration, not what data you will be sending over. The serial port data is wrapped into USB packets ant sent as bursts. You will not see 115200 clocked pulses when you look at the waveform on an oscilloscope.

author: Whales
author_rank: Super Contributor
timestamp: January 12, 2024, 02:48:49 pm
content: Quote from: Ogitek on January 12, 2024, 02:24:20 pmNo.The USB bus will still be sending data at a higher rate, just with gaps in between. A bit like how you can either walk to the shops OR sprint then rest then sprint then rest.

author: wraper
author_rank: Unknown
timestamp: January 12, 2024, 02:52:08 pm
content: Quote from: magic on January 12, 2024, 02:28:38 pmDepends on length. Short wires will work.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 12, 2024, 02:53:05 pm
content: Quote from: dobsonr741 on January 12, 2024, 02:43:49 pmWhat I mean is the V+ gets into one of the twisted pair due to rewiring of the USB cable with a LEMO plug at one end with wrong pins. For example. You purchase this USB to LEMO cable:https://www.amazon.com/gp/product/B06XKV73C1/ref=ewc_pr_img_1?smid=A1PUUT3OIOMJ0X&psc=1But in your equipment LEMO has other pinout than it. So what you do is cut the USB cable into half, and rewire them to match the pins. What would happen is either the V+ or V- can become go inside one of the twisted pair.If USB 2.0 always run at 480Mbps even if the data is only 4800 bps. And you rewire the cable above. then it won't run anymore even if the USB source and your equipment has the right pins already??

author: Andy Chee
author_rank: Super Contributor
timestamp: January 12, 2024, 02:56:36 pm
content: Quote from: Ogitek on January 12, 2024, 02:24:20 pmThe speed between your legacy serial device and the converter would be 115,200bps. But the speed between the converter and USB host/PC would 1.5MB/s. Of course, the speed mismatch means the USB converter has to "translate" between the two.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 12, 2024, 03:00:06 pm
content: Quote from: wraper on January 12, 2024, 02:57:57 pmI don't know how to solder the micro LEMO pins.. so instead I plan to rewire it at the middle of the cables by cutting it and rewiring the individual wires. and not changing the pin ends. So it won't work at all?

author: wraper
author_rank: Unknown
timestamp: January 12, 2024, 03:04:41 pm
content: Quote from: Ogitek on January 12, 2024, 02:53:05 pmIf you do that, you rewire either within LEMO connector of as close as possible to it. Watch some videos about how to properly solder FFS.

author: Andy Chee
author_rank: Super Contributor
timestamp: January 12, 2024, 03:06:02 pm
content: Quote from: Ogitek on January 12, 2024, 03:00:06 pmIf the converter is located within the molded USB plug body like so, then the rewiring should be ok. Strictly speaking, anything after the converter, no longer requires to be compliant with the USB protocol.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 12, 2024, 03:08:45 pm
content: Today I got the above USB cable. I plan to solder the end to the LEMO plug clone when it arrives next week. Let's say I would be successful in soldering them to the plug. And it will be used in USB 2.0 equipments. Are you sure it won't run at 480Mbps (with a length of it not twisted)?Or did you mean even if you use straight stranded wires. Sometimes the USB 2.0 can run. Sometimes it can't. Or 100% can't all the time?

author: ejeffrey
author_rank: Super Contributor
timestamp: January 12, 2024, 03:09:28 pm
content: Quote from: Ogitek on January 12, 2024, 02:41:21 pmYes. What matters is the USB operating mode not the amount of data transmitted.Keep in mind USBs "interesting" naming. The USB 2.0 standard superseded 1.1 and continues to include lower speeds. So while normal people make the totally reasonable association that "USB 1.1 is 1.5 or 12 megabit, USB 2.0 is 480 megabit" that's not actually how USBIF wants you to use those terms. USB 2.0 devices can be low speed (1.5) full speed (12) or high speed (480).A high speed device will transmit data at 480 megabit / s always and requires appropriate signal integrity.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 12, 2024, 03:19:30 pm
content: Quote from: Andy Chee on January 12, 2024, 03:06:02 pmI was talking about rewiring in middle of wire with a USB and LEMO male at its end. I wasn't referring to the converter in the rewiring. But then even in the conventer. If you rewire the middle (let's say the USB male pin is incorrect), and the V+ gets into the twisted pair, and you are running it at USB 2.0 at 480 Mbps. Why would it run at all? I thought 480 Mbps require the middle to be twisted in the data lines.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 12, 2024, 03:23:34 pm
content: Quote from: ejeffrey on January 12, 2024, 03:09:28 pmSo if the equipment is high speed. It won't decrease to low speed (1.5) mode just because it couldn't negotiate at the higher speed?

author: Andy Chee
author_rank: Super Contributor
timestamp: January 12, 2024, 03:27:59 pm
content: The minimum USB speed is 1.5Mbits/shttps://en.wikipedia.org/wiki/USB_communicationsIf a USB 2.0 is plugged into a USB 1.0 port (or vice versa), then the speed will be negotiated at 1.5Mbits.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 12, 2024, 03:31:51 pm
content: Quote from: Andy Chee on January 12, 2024, 03:27:59 pmSo USB 2.0 can readjust from 480Mbps to 1.5 Mbps if the wiring is not good. Why did you guys say the speed is fixed?

author: Andy Chee
author_rank: Super Contributor
timestamp: January 12, 2024, 03:33:45 pm
content: Quote from: Ogitek on January 12, 2024, 03:31:51 pmIncorrect.Bad (or good) wiring has nothing to do with negotiation. It's the USB device and USB host that does the negotiation. The USB device/host has no idea of the condition of the wiring.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 12, 2024, 03:33:55 pm
content: I first became aware of all this a while ago when googling whether USB cable should be shielded or not. Then I came across this:https://electronics.stackexchange.com/questions/430914/a-few-of-my-cables-dont-work-is-it-because-they-werent-shielded-properly"According to baseline USB 2.0 specifications, the USB cable must have signal (green-white) wires as a twisted pair with 90 Ω differential impedance.And no, the shield should connect only metal shells, and shouldn't be connected to GND wire at all, see section 6.5.2 of USB 2.0 specifications.Some of your cables do not work reliably likely because you have too wide cut-offs near soldering area, which creates impedance discontinuity, which causes reflections and intersymbol interference. USB cables must be tested on TDR (Time-Domain-Reflectometer) to ensure impedance uniformity across soldering joints."That page is saying that even in normal fully twisted USB cable, the soldering at the end can even impact it and you need to use Time Domain Reflectometer to check??A while ago. I was about to transact with a China cable fabricator at Ebay who will assemble USB cable with LEMO clone. So without proper soldering or using the right cable. It won't even run even if all pins rightly connected!I think I'd better buy the original $400 USB-LEMO cable for my sound system. I want to save on it by trying to recreate it, but encountered so many issues.

author: Andy Chee
author_rank: Super Contributor
timestamp: January 12, 2024, 03:38:49 pm
content: Quote from: Ogitek on January 12, 2024, 03:33:55 pmIt completely depends on where in the transmission chain you want to rewire. If it's a low speed non-USB section (for example RS232), then it shouldn't be a problem.But yes, your LEMO device looks like it relies on high speed signalling, so better go with an original cable.

author: magic
author_rank: Super Contributor
timestamp: January 12, 2024, 04:17:17 pm
content: USB 1.x defines two speeds: low (1.5Mbps) and full (12Mbps).USB 2.0 defines a new speed: high (480Mbps) and still permits the lower speeds to be used.HS hosts and devices can fall back to FS if the other end doesn't support HS.If the cable is very dodgy, it may look like HS is not supported and the link will work at FS.If the cable is slightly dodgy, HS may be enabled and then fail to actually move data.There is no fallback from FS to LS. An FS device simply fails if connection is too bad for FS.UART/RS232 dongles usually are FS only. Some fancy ones may be HS.

author: wraper
author_rank: Unknown
timestamp: January 12, 2024, 04:56:19 pm
content: Quote from: Ogitek on January 12, 2024, 03:31:51 pmBecause you just wrote absolute BS despite being told multiple times how it is actually.

author: wraper
author_rank: Unknown
timestamp: January 12, 2024, 05:04:58 pm
content: Quote from: magic on January 12, 2024, 04:17:17 pmOnly is USB sink device is specially designed to be able to reset interface on communication fail at HS and then restart without negotiating HS (not likely you'd find something like this).

author: magic
author_rank: Super Contributor
timestamp: January 12, 2024, 05:49:12 pm
content: No, it can happen with any device. It may take tens of tries to get it right, but you can make any HS device work at FS by inserting the plug very slowly or at weird angle to make the contact poor enough. (It helps to watch dmesg in Linux in real time).The reason it works is because a HS device first appears as FS and immediately sends a "high speed chirp" signal which old hosts/hubs ignore, but new ones recognize and respond to. If this signal doesn't reach the hub, the device will be enumerated as FS and every device which wants to support legacy hosts is prepared to deal with this.In theory a device could refuse to work at FS at all, but I don't recall ever seeing such device. Even my USB 3.0 camera can fall back to FS with 320x240 resolution.

author: wraper
author_rank: Unknown
timestamp: January 12, 2024, 05:56:50 pm
content: Quote from: magic on January 12, 2024, 05:49:12 pmWell if you interrupt sending chirp signal, then yes. However I really doubt chirp won't go through just because of crappy cable.

author: magic
author_rank: Super Contributor
timestamp: January 12, 2024, 06:28:34 pm
content: I think you're right, the chirps are supposedly 50μs in duration so it seems impossible to suppress them passively without breaking FS signaling as well.So my dodgy insertion trick must be a matter of intermittency rather than resistance or anything like that.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 12, 2024, 11:17:20 pm
content: I cut the USB 2.0 cables I own to see what is really inside in case there is a way to save $400 usb-lemo cable. But I found out none of them is even twisted! So what you make of it? Fake 480Mbps and just FS of 12 Mbps?What branded USB cable do you know that is really twisted? have you open yours too?In audio devices and ADCs. Do they really need 480Mbps, or do most run in 12Mbps? Remember this is already much faster than serial port of 115,200 baud (or 0.1152 Mbps)

author: Ogitek
author_rank: Regular Contributor
timestamp: January 13, 2024, 12:40:49 am
content: I cut all my USB cables, even the flat one, and found out none is twisted. Just when I thought USB 2.0 was very slow and wanted USB 3.0 and just knowing now I haven't even tasted real 480Mbps. I have a Western Digital model that says USB 3.0. What software can I use to find out if it is running Superspeed of 5Gbps and not USB 2.0 High Speed or even Full Speed?

author: Ogitek
author_rank: Regular Contributor
timestamp: January 13, 2024, 02:09:02 am
content: I'm googling a certain information I can't find.If the data lines are not twisted but only very short length like less than one meter. Can it still somehow run USB 2.0 High Speed of 480Mbps?Maybe only when the cable is beyond certain length that twisting is necessary for High Speed? What is the magic length?

author: Ogitek
author_rank: Regular Contributor
timestamp: January 13, 2024, 06:05:41 am
content: Quote from: magic on January 12, 2024, 05:49:12 pmCan the manufacturer disable this on purpose, not able to negotiate at FS at all but only HS? Supposed you are manufacturing very expensive audiophile amplifiers and equipments, and you only want the customers to buy your $400 usb-lemo cable, and you didn't want any cable clone to duplicate it. Is it possible to only enable HS, or is the ability to negotiate to FS in every firmware that can't be bypassed or vetoed?Remember Audiophile equiptment can cost more than $10000 and people fight over them at ebay.

author: Andy Chee
author_rank: Super Contributor
timestamp: January 13, 2024, 06:51:35 am
content: Quote from: Ogitek on January 12, 2024, 11:17:20 pmWhilst ethernet cable wire pairs have 5 twists per 1 inch, USB cables go as low as 1 twist per 5 inches. So you will need to remove a whole lot more plastic sheath to reveal the twists.Quote from: Ogitek on January 13, 2024, 06:05:41 amIf they did, the product would no longer be "USB compliant", completely defeating the termUniversalSerial Bus.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 13, 2024, 07:24:59 am
content: Quote from: Andy Chee on January 13, 2024, 06:51:35 amAre you saying all USB 2.0 cables have the data lines twisted? How about this. It's a flat all the way, there is no way to twist any wire:So they are the only USB 2.0 cables that don't have a twist? And it's a sure way to force any HS device to renegotiate at FS by suppressing the chirp?Also any reference for the chirp signal sent that can heard over the other end?

author: tooki
author_rank: Super Contributor
timestamp: January 13, 2024, 07:28:00 am
content: Quote from: Andy Chee on January 13, 2024, 06:51:35 amFYI, that’s a gross oversimplification. Neither the Ethernet nor cable standards actually specify the number of twists per inch, only performance targets (like bandwidth and crosstalk), with the manufacturer free to meet them however it wants. But the most important thing to remember is that each pair uses a different number of twists per inch, to reduce crosstalk by avoiding running in parallel regularly.The number of twists per inch goes up with higher category cables, also.

author: Andy Chee
author_rank: Super Contributor
timestamp: January 13, 2024, 07:32:11 am
content: Quote from: Ogitek on January 13, 2024, 07:24:59 amThose flat cables are extremely unreliable in a high electrical interference environment.

author: Andy Chee
author_rank: Super Contributor
timestamp: January 13, 2024, 07:38:08 am
content: Quote from: tooki on January 13, 2024, 07:28:00 amUSB standard also does not specify twists per inch, only performance targets.

author: tooki
author_rank: Super Contributor
timestamp: January 13, 2024, 07:40:00 am
content: Quote from: Ogitek on January 13, 2024, 07:24:59 amYou can’t see the twisting by stripping just a few mm.If you were to slit the cable down its length and peel off the jacket, you should see twisting of the data pair — assuming the cable is actually compliant, which is not a given, thanks to the glut of shitty cables out there.Attached are photos of what proper, compliant cable should look like (including some USB 3 just for illustration). A ton of USB cables out there are not compliant, and work by luck and/or using up all the margins for error in USB’s design.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 13, 2024, 08:16:28 am
content: Here I cut 2 more inches (uncrop so you can see every details). There are no twists in the green and white or any wire, or is it possible to have one turn every say 5 inches? Whatever, what brand is guaranteed to have twists and proven to be USB 2.0 compliant. Or the most Milspec USB 2.0 availab.e I'd like to hold a genuine one to feel a real year 2000 technology, which I missed.

author: tooki
author_rank: Super Contributor
timestamp: January 13, 2024, 08:28:40 am
content: Quote from: Ogitek on January 13, 2024, 08:16:28 amI guess you didn’t read all the earlier replies, especially this one (bold added by me):Quote from: Andy Chee on January 13, 2024, 06:51:35 amAnd you’ll need to do it carefully to ensure you’re not straightening out the twist as you strip it. Slit the insulation down a foot of the cable and peel it off like you would a banana peel. Don’t strip little by little by cutting around the circumference and sliding down the wires.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 13, 2024, 09:46:20 am
content: Yes, there appears to be some kind of twists but the Red and Black wires are also twisted along with the green and white. But then, couldn't it be during manufacturing, the twisting of the wires are random?Anyway. I'm trying to find references about the numbers of twists per x inch in USB wires. Where can one find it? Because I saw the following that there must be 4 twists per inch to avoid crosstalk. Also where are you supposed to measure the impedance of 90 ohms? in between green and white? but with respect with what resistance (since it has distance between them and not shorted)?

author: Andy Chee
author_rank: Super Contributor
timestamp: January 13, 2024, 09:52:19 am
content: Quote from: Ogitek on January 13, 2024, 09:46:20 amCrosstalk in ethernet cable (and bundled telephone copper pairs in general) doesn't exist with USB, because USB only has one channel i.e. there's no other channel to crosstalk!That said, if you bundled several USB cables in parallel, then maybe you would get crosstalk. But long parallel USB cables could be avoided by using a single cable with a USB hub on the end.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 13, 2024, 10:45:07 am
content: Ok. So if the Vention is really USB 2.0 that can negotiate at 480Bps well and you just replace one of the head with a Lemo. why wont it work? What made a cable "dodgy"? does dodgy refer to the manufacturer, so if one choose a good brand like Vention and add a Lemo plug. It wont be dodgy and can work?

author: Andy Chee
author_rank: Super Contributor
timestamp: January 13, 2024, 11:06:19 am
content: If you just replace the plug at the very end of the cable, that should be ok.But if you try to replace a large 24 inch section of cable with untwisted wire, then that is a very different scenario which may impact signal integrity.

author: tooki
author_rank: Super Contributor
timestamp: January 13, 2024, 11:22:29 am
content: Quote from: Ogitek on January 13, 2024, 09:46:20 amNo, that’s not how cable is manufactured, the twist has to be added on purpose.Quote from: Ogitek on January 13, 2024, 09:46:20 amAs you’ve already been told, the USB specification doesn’t specify a number of twists, only that it be twisted, and then performance specs that must be met.There are clearly huge differences in the number of twists used, and as I’ve said, many cheap cables would fail compliance testing if they were actually ever subjected to it. They just happen to be barely good enough to work most of the time. But they might fail in electrically noisy environments, for example.Twisting not only reduces crosstalk, it also reduces sensitivity to electromagnetic noise, because the twisting causes the noise to sort of cancel out.Quote from: Ogitek on January 13, 2024, 09:46:20 amYou can’t measure this yourself. (You would need a very expensive piece of equipment called a Vector Network Analyzer.) The 90 ohms isn’t the resistance, it’s what’s called “characteristic impedance”, which is a function of its behavior with high frequency signals.

author: tooki
author_rank: Super Contributor
timestamp: January 13, 2024, 11:24:35 am
content: Quote from: Andy Chee on January 13, 2024, 09:52:19 amWell, with USB HS, FS, and LS. With USB 3.0, there are multiple pairs.And I suppose that theoretically, noise on the power rails could be coupled to the data pair, or vice versa.But I suppose the primary reason for twisting in USB is to reduce common-mode noise.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 13, 2024, 12:20:04 pm
content: Quote from: Andy Chee on January 13, 2024, 11:06:19 amWhat if I cut the original Venton USB in half and put Lemo at one end of one of the pairs? In other words, does the manufacturer have to design the twisting of each cable with certain numbers and design each complete cable or can they just cut their roll of wiring for every one meter and put termination into it?

author: Andy Chee
author_rank: Super Contributor
timestamp: January 13, 2024, 12:42:22 pm
content: Quote from: Ogitek on January 13, 2024, 12:20:04 pmYou can cut to any length and replace the plug. The twists do NOT have to be "integer" lengths, so to speak.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 13, 2024, 12:58:54 pm
content: Quote from: Andy Chee on January 13, 2024, 12:42:22 pmWhat have you heard about "Impedance discontinuity"? This thread started because I was reading this physics stack exchange topic. Someone soldered it this way:And someone answered:https://electronics.stackexchange.com/questions/430914/a-few-of-my-cables-dont-work-is-it-because-they-werent-shielded-properly"Some of your cables do not work reliably likely because you have too wide cut-offs near soldering area, which creates impedance discontinuity, which causes reflections and intersymbol interference. USB cables must be tested on TDR (Time-Domain-Reflectometer) to ensure impedance uniformity across soldering joints.".What does he mean by "wide cut-offs"? Does it means the distance between solders is wide? So you can't use other plugs for USB? If you use a Lemo plug. Why won't it cause impedance discontinuity?

author: Andy Chee
author_rank: Super Contributor
timestamp: January 13, 2024, 01:08:03 pm
content: Please refer to my edited image. The section marked in blue, is what potentially causes an impedance discontinuity. This section should be kept very short, which unfortunately doesn't provide much wiggle room and makes hand assembly somewhat tedious.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 13, 2024, 01:16:43 pm
content: Quote from: Andy Chee on January 13, 2024, 01:08:03 pmI don't get it. Should it be very short so it is enclosed by the shield? or because there is less twisting (but then, twisting can occur one turn every 5 inches so it's negligible)? What else? And how does it differ to the USB cable soldered to a LEMO plug like the following?

author: Andy Chee
author_rank: Super Contributor
timestamp: January 13, 2024, 01:41:56 pm
content: Quote from: Ogitek on January 13, 2024, 01:16:43 pmThe LEMO plug is a metal body, so it shields the wires. Just make sure the shield is connected to the plug body.If the plug body was plastic, then yes, it needs to be short in order to be enclosed by the shield.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 13, 2024, 01:48:21 pm
content: Quote from: Andy Chee on January 13, 2024, 01:41:56 pmOk thanks. I heard that the termination in the USB 2.0 must be designed to have the same characteristic impedance as the twisted pair. Have you heard of this? What if they are different?

author: voltsandjolts
author_rank: Unknown
timestamp: January 13, 2024, 01:50:07 pm
content: You are making this hard for yourself. So many posts.Looking back at your posts, you've mentioned bio-medical signal amplifiers, baud rates and copying a commercial USB-LEMO (or USB-ODU) data cables you posted pictures of. So, I'm going to guess you have some used medical measurement system which interfaces to a PC via USB, likely at those baud rates you've mentioned (USB-CDC device). The data rates required in this type of system would be modest and it's likely your device (is it a secret what it is?) is using USB-FS (12MHz) and not USB-HS (480MHz). If that is correct, this cable will be easy to make without worrying about imepdance matching and reflections. By way of it's low bit rate and error correction, USB-FS is tolerant of crappy layout and cables.Because you continue to struggle, I re-iterate my previous post suggesting you use USB breakout boards which are ideal for someone less skilled in the art of custom USB cables. For example, the breakout board shown below, then twist your own wires and solder to your LEMO or ODU connector. Perhaps you could use PTFE wire which is tolerant to overheating during clumsy soldering.

author: Andy Chee
author_rank: Super Contributor
timestamp: January 13, 2024, 02:15:47 pm
content: Quote from: Ogitek on January 13, 2024, 01:48:21 pmThe circuit termination is not really in the cable per se. The circuit termination is on the PCB next to the USB chip of the PC, and on the PCB next to the USB chip inside your device. Circuit termination could also be within the chip as well.If impedances are wildly different, you get signal reflections, which may or may not be interpreted as extraneous bits in the serial data, depending on how well error detection & correction does its job. Too many extraneous bits and you will lose data. Recall the discussion on the previous page, USB protocol has no speed reduction when encountering bad data.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 13, 2024, 02:36:40 pm
content: Thanks for all the information guys. I'm deciding whether to get a $42 cable from China (someone at Ebay told me he can assemble a clone) versus getting the $400 original one. You see, the thing is, the Audiophile equipment Im bidding is untested (I haven't received it yet). I don't want to fry the USB board if I solder a bad cable myself (I dont' know how to solder well). It is confirmed to be USB 2.0 with HS of 480Mbps. If I used the china clone, there may be impedance mismatch that can cause the USB not to work, which may make me think the equipment is not working. So I guess I may just invest in the $400 usb cable. I thought USB cable was just a conductor. Well it is not, it is a transmission system!

author: tooki
author_rank: Super Contributor
timestamp: January 13, 2024, 05:08:11 pm
content: You're burying yourself in detail you don't understand, and have created 4 threads about this special cable, without reaching any real conclusion , in part because you aren't listening to what people say.Yes, impedance matching and discontinuities matter, but the system has to tolerate some because of the physical realities of manufacturing low-cost cables. (USB was designed to be low cost, so it has to allow some tolerances.) The issue in the DIY cables you linked is that the guy wasn't connecting the shield, which is absolutely required.If the Chinese cable is designed specifically for your device, so that the pinout is definitely correct, go with that. You won't get one cheaper. We'd love to simply verify whether the Chinese cable will be correct, but despite being asked more than once, you refuse to just tell us what the damned piece of equipment is.Quote from: Someone on January 04, 2024, 04:21:24 amQuote from: tooki on January 04, 2024, 11:50:00 am

author: magic
author_rank: Super Contributor
timestamp: January 13, 2024, 09:09:30 pm
content: It supposedly is "audiophile equipment", so forking out $400 for cables is the obvious thing to do and frankly a bargain(Myself, I would surely solder something together and no way it would be worse than the OEM product...)

author: Ogitek
author_rank: Regular Contributor
timestamp: January 13, 2024, 10:54:12 pm
content: I still don't have the equipment, it is still on the way from a seller in Taiwan. The mail is long. I'm not even sure the equipment works. In case it doesn't work. I want to get one of 2 remaining items left at Ebay. If I tell you now and some of you empty the shelf. Then I won't have any more left over to get. I'll tell you guys what it is after I received it and it's working.About the lemo cable clone from China. It would be custom made by Eonvic. However. They won't use branded USB cables. Instead, they may just use generic USB 2.0 cable which may not be up to specs. Has anyone of you own any Eonvic product like this?https://www.amazon.com/gp/product/B06XKV73C1/ref=ox_sc_act_title_1?smid=A1PUUT3OIOMJ0X&th=1What generic china USB 2.0 cable do they use?About the $400 original USB lemo cable. When you go to tire shop and have your flat tire patched. They rotate it and put some small iron to make it balance. So in the case of the original Lemo USB. Maybe they do something similar to it to patch the impedance mismatched by maybe increasing the diameter of the wire at the end or make the insulator thicker? This is close up picture of the original cable by another Ebay seller of the equipment which includes cable. Do you recognize what kind of cable is that? Maybe even Milspec?

author: Ogitek
author_rank: Regular Contributor
timestamp: January 13, 2024, 11:04:59 pm
content: I tried zooming in the cable picture above now and seem to make out the words "CMG LL84201 CSA CABLE COPARTNER FT4". I googled it and the following page comes up.https://www.ebay.com/itm/374199291173UTP Patch Cable? The original $400 USB LEMO didn't even use USB cable but a UTP Patch Cable? What you make of it? They used ODU plug size 0 compatible with the Lemo FGC.0B.

author: abeyer
author_rank: Frequent Contributor
timestamp: January 14, 2024, 01:24:31 am
content: Quote from: magic on January 13, 2024, 09:09:30 pmTrue, but creating long meandering threads of psuedo-scientific/engineering blabber without really knowing what you're talking about is also quite on point for audiophoolery.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 14, 2024, 04:31:43 am
content: utp = un-shielded twisted pairsFT4 specification from :https://www.sycor.com/blog/post/csa-ft1-ft2-ft4-ft5-and-ft6The FT4 certification is one of the most popular as it has one of the toughest tests to pass, given the 70,000 BTU/hour flame. This certifications testing procedure has cables mounted on a vertical tray, which are exposed for 20 minutes to a 70,000 BTU/hour flame. This test is identical to the IEEE 1202 flame test. The FT4 and IEEE 1202 reduced char height requirements make them slightly more difficult to pass than the UL1685 vertical tray version.The pass or fail criteria for the FT4 certification is the finished wires or cables shall not exhibit charred material beyond a length exceeding 1.5 m (5 ft.) from the lower edge of the burner face when subjected to the test (CSA C22.2 No.38).for an usb to the lemo, any good usb cable should have 4 conductors plus a shield, better if it's a foil and shielded braid, you connect the end shield to the lemo casingand yes this threadclose it

author: Ogitek
author_rank: Regular Contributor
timestamp: January 14, 2024, 06:52:23 am
content: You didn't answer why the original USB Lemo cable shown in the picture uses ethernet cat5 cable (with 4 pair of twisted wires). I read ethernet wire has higher impedance like 100 Ohm). Is this to match the Lemo plug which is 100 Ohm for impedance match. Or is it irrelevant and one can use USB cable or ethernet cable for USB 2.0?The China cloner is waiting for my payment and I need to know the last critical information above to make the final decision. Thanks.

author: voltsandjolts
author_rank: Unknown
timestamp: January 14, 2024, 10:28:15 am
content: The connector in your picture above is not a Lemo.You've already been told what it is in another one of your moronic threads.

author: Gyro
author_rank: Super Contributor
timestamp: January 14, 2024, 10:52:47 am
content: Surely for an Audiophile cable you should be specifying OFC (Oxygen Free Copper) cable conductors. Gold plated USB connector contacts and shell, and a genuine Lemo connector rather than a Chinese clone?

author: tooki
author_rank: Super Contributor
timestamp: January 14, 2024, 11:00:44 am
content: Quote from: Ogitek on January 13, 2024, 10:54:12 pmLMAO. This isn’t an audiophile forum, and if anything, is generally very skeptical of “audiophile” stuff because stuff so labeled (and people who call themselves that) are frequently quite divorced from objective reality…Quote from: Ogitek on January 13, 2024, 10:54:12 pmLOL no. Again, as I have already explained to you, impedance mismatch was not the problem with the failed cables in that thread you’re giving so much weight to. The problem is that they didn’t connect the shield at all. The shield is essential.Quote from: Ogitek on January 13, 2024, 10:54:12 pmThat’s a cheap generic USB cable with a LEMO-style plug added to one end. That’s it.Quote from: Ogitek on January 13, 2024, 11:04:59 pmAnd if you looked at more search results, you’d find that the same markings are found on a wide variety of cables, including VGA cables and serial cables. So you’re definitely wrong in assuming it means it’s Ethernet cable.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 14, 2024, 11:05:44 am
content: Quote from: voltsandjolts on January 14, 2024, 10:28:15 amLemo is compatible to Odu. And since Odu is not a clone of Lemo. I refer to it as Lemo just for sake of discussion. This is in contrast to Lemo clone which are brandless.Quote from: Gyro on January 14, 2024, 10:52:47 amYou have a point. I'm recording nature's sounds. And don't want to miss a note. What is the impedance of original Lemo vs Lemo clone?

author: Gyro
author_rank: Super Contributor
timestamp: January 14, 2024, 11:08:43 am
content: Quote from: Ogitek on January 14, 2024, 11:05:44 amWho knows, it's a Chinese clone!Edit: Seriously though, I don't think you are going to find an answer here that will satisfy you.

author: magic
author_rank: Super Contributor
timestamp: January 14, 2024, 11:13:36 am
content: Is that original Lemo connector even rated for wave impedance at all?Anyone has a datasheet or knows the exact part number?Or is the 'phool vendor using it only because it looks cool, sounds better than micro-USB and requires thesucke, pardon, customers to purchase a custom cable for $400?Anyway, USB 2.0 can run over all sorts of garbage cables and connectors (this one is probably another testament to USB's robustness), so it shouldn't matter much what particular garbage you use...

author: Ogitek
author_rank: Regular Contributor
timestamp: January 14, 2024, 11:17:18 am
content: Quote from: magic on January 14, 2024, 11:13:36 amI thought USB 2.0 Hi-Speed (480Mbps) can't run over all sorts of crap cables and connectors and it has to change mode to USB 1.1 Full-Speed (12Mbps)? If I'll try to test my USB 2.0 to my external drive via a USB Hub. Where can I see the speed displayed in 480Mbps or 12Mbps?

author: Ogitek
author_rank: Regular Contributor
timestamp: January 14, 2024, 11:18:37 am
content: Quote from: Gyro on January 14, 2024, 11:08:43 amAre chinese LEMO clones also made of Nickel and chrome plated? How do I know? I have 2 pcs coming in a week.

author: Andy Chee
author_rank: Super Contributor
timestamp: January 14, 2024, 11:23:47 am
content: Quote from: Ogitek on January 14, 2024, 11:05:44 amThe impedance mismatch in the USB section of the cable is mostly irrelevant due to the USB protocol's error detection & correction.Arguably the impedance in the analog cable section of your audio chain is also irrelevant, but given the general vibe of your questions, this is beyond your understanding.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 14, 2024, 11:25:02 am
content: Quote from: magic on January 14, 2024, 11:13:36 amThe China wire suppliers said he would use UGreen to solder to the Lemo clone. So comparing it to a real LEMO plug. There would be a difference in the data? USB 2.0 has no error correction and so garbages can occur? I don't want the sound of waterfall to have noise that would sound like the cry of a wolf inside it because it will totally destroy the purpose.

author: tooki
author_rank: Super Contributor
timestamp: January 14, 2024, 11:30:39 am
content: Quote from: Ogitek on January 14, 2024, 11:05:44 amThough both companies are approximately the same age, ODU didn’t release its push-pull circular connectors until30 yearsafter LEMO introduced its. So no, LEMO isn’t “compatible  ODU”, and ODU is the clone of LEMO. One of many clones, and at least one made by a reputable, quality manufacturer. ODU also makes clones of Fischer connectors, another brand of similar-style circular connectors (which aren’t compatible with LEMO, though).Note that in connectors, we usually consider something to be a clone if it is fully compatible (= designed to intermate with the original), even if there are differences in design, like how they assemble or the design of grips. (In contrast with second-sourcing, where the parts must be identical and interchangeable.)

author: Andy Chee
author_rank: Super Contributor
timestamp: January 14, 2024, 11:32:46 am
content: Quote from: Ogitek on January 14, 2024, 11:25:02 amUSB has cyclic redundancy checking. It can tolerate a lot of garbage before complete failure.

author: tooki
author_rank: Super Contributor
timestamp: January 14, 2024, 11:43:51 am
content: Quote from: Ogitek on January 14, 2024, 11:05:44 amThey aren’t impedance-controlled.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 14, 2024, 11:44:03 am
content: Quote from: Andy Chee on January 13, 2024, 02:15:47 pmThis is the deciding factor. You said even with error correction, error can still occurs and data can get lost between wires with subtle crapiness?? If yes, then need the original cable because I'm splitting hairs and detecting on the boundary between silence and sound, or measuring the sound of silence.

author: wraper
author_rank: Unknown
timestamp: January 14, 2024, 11:44:58 am
content: Quote from: Andy Chee on January 14, 2024, 11:32:46 amIt can tolerate errors, but just a little bit.

author: tooki
author_rank: Super Contributor
timestamp: January 14, 2024, 12:01:20 pm
content: Quote from: Ogitek on January 14, 2024, 11:17:18 amStill no.High-Speed (HS) devices won’t fall back to full-speed (FS) mode when the cable is poor. USB 2.0 devices* negotiate the mode based on the highest mode supported by both host and device, irrespective of the cable used. So if both device and host support HS, then HS is theonlymode they will use, and if the cable then fails to make that speed function properly, the connection will simply fail. It will NOT renegotiate down to FS.In contrast, if there is a mismatch in the highest supported mode, the host and device may be able to use FS mode.- If the host supports HS but the device doesn’t, it will use FS or LS, as needed by the device.- If the device supports HS and FS, but the host doesn’t support HS, then it’ll use FS.- If the device requires HS, but the host does not support it, the device driver won’t load.*Remember, the USB 2.0 standard includes the USB 1.1 standard, so every USB 1.1 low-speed (LS) or 1.1 FS device is also a USB 2.0 LS or 2.0 FS device. USB 2.0 does NOT require a device to support HS mode.

author: tooki
author_rank: Super Contributor
timestamp: January 14, 2024, 12:14:59 pm
content: Quote from: Ogitek on January 14, 2024, 11:44:03 amThat’s not what he said. He said error correction, then total failure. Note the absence of anything in between.USB has error correction and detection, but once there are uncorrectable errors, the connection fails completely. It doesn’t tolerate uncorrected errors, you just get disconnected.Quote from: Ogitek on January 14, 2024, 11:44:03 amThat’s not how digital audio works, nor how USB works, nor how digital audio over USB works. A random error in a digital audio stream can have a completely irrelevant effect, or a horrible one, on a sample, depending on which bit of the sample happens to be flipped. That’s why CDs use multiple layers of error correction, and will interpolate missing samples rather than skip them.But because of how data is sent over USB, you’ll never have “marginal” data like you seem to think. It’ll either be 100% correct, or it won’t arrive at all, so to speak.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 14, 2024, 12:18:58 pm
content: Quote from: tooki on January 14, 2024, 12:01:20 pmThanks for that summary. My mixer is 16 channels with 16 ADCs and 24 Bit each so I'm sure it uses Hi Speed of 480Mbps for simultaneous transfer to the PC. Ok. I'll get just the original cable then, just to be sure. After I got the mixer and it's working. I'll tell you all what it is. This is to protect a backup plan at Ebay that I need to acquire in case it's not working. Thanks a lot guys.

author: ejeffrey
author_rank: Super Contributor
timestamp: January 14, 2024, 06:51:09 pm
content: Quote from: Ogitek on January 13, 2024, 02:09:02 amThere is no spec on how bad your wires have to be to guarantee the connection won't work. 480 Mbit/s is not terribly fast, it's likely to work over a wide range of crappy non compliant wiring. Also the wiring requirements are probably as much or more driven by making sure devices have a chance of passing EMI than signal integrity.

author: magic
author_rank: Super Contributor
timestamp: January 14, 2024, 07:08:18 pm
content: Well, EMI goes both ways. My aforementioned dodgy cable connecting an internal USB card reader to the motherboard had this interesting property that if the second "lane" in the cable was used simultaneously by a full speed peripheral (12Mbps 3.3V signaling), the card reader would drop off the busBut it would take deliberate effort to create something worse than a $400 audiophile USB cable

author: Ogitek
author_rank: Regular Contributor
timestamp: January 15, 2024, 10:49:59 pm
content: https://web.lemo.com/img/resources/catalog/ROW/UK_English/High_speed_data_transfer.pdfI found some information related to all this (someone shared to me). LEMO has made special insert configurations just for USB 2.0 and USB 3.1 and they happen to use the 4 wire pin we are talking about. For other LEMO pin configurations like 3 pin or 5 pin. It is not USB 2.0 compliant. This means the China LEMO 4-pin clone doesn't have special pin characteristic so can't do a 480Mbps? (too much impedance mismatch causing so much reflections that can't transmit the 480Mbps)

author: ejeffrey
author_rank: Super Contributor
timestamp: January 15, 2024, 11:54:50 pm
content: The USB 3.1 version obviously isn't 4 pin as USB 3.1 requires at least 8 pins. Nothing in this thread so far has talked about usb 3+ so I'm going to ignore that for now.You would have to make a catastrophically bad connector to fail to work for usb 2.0. A bad cable maybe but the connector is just too small and absent deliberate inductors in the signal path or failing to connect a wire altogether its going to work. That doesn't mean that audiophile idiots making $1000 cables can't fuck up that badly, just that they would have to be dumber than a 2 year old, or more likely deliberately sabotaging it in order to sell a $1000 filter to fix the problem they caused.LEMO connectors are great when you need super rugged and easy to assemble custom connectors. They are in no way better performance than a $2 monoprice overmolded USB cable. So this whole premise is nonsense.One note: USB connectors are designed with the power and ground pins longer than the data pins. You can see this quite clearly on a standard type A plug. This is important for hot plugging bus powered devices, and shorting out common mode voltage to prevent damage. A non standard connector not specifically designed for USB is very likely to get that wrong. It doesn't matter for signal integrity but could cause problems with hot plugging.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 16, 2024, 09:56:09 am
content: So you are saying LEMO just made it up.. telling people their 4-pin have special impedance that matches that of twisted wires, and it is not true at all. But then for USB 3.1. It can also run on normal pins? So they made it up as well?Anyway. I got the following from one of the threads here. The left one is genuine Lemo, the right one is fake or clone. What do you think is the MTBF (Mean Time Between Failure) of the Lemo clones? In your experience. 1/4 that of Lemo? 1/8? or even 1/20th of original?I need other cables as I have to move my gear to house, studio, work and need to plug and unplug the Lemo (clone) connectors many times a day.https://www.eevblog.com/forum/chat/a-tale-of-two-lemo-connectors/msg1273862/#msg1273862

author: tooki
author_rank: Super Contributor
timestamp: January 16, 2024, 10:51:51 am
content: Quote from: Ogitek on January 15, 2024, 10:49:59 pmI saw that document long ago. It’s just their recommendations. As far as I can tell, they aren’t special insert configurations, at least not for USB 2, they’re just their standard 4-pin inserts in the recommended sizes, with a recommended pinout. They probably calculated which of their existing inserts works best for USB 2 and recommend that connector size. Because if you look at their overall catalog, “304” is one of their standard insert sizes, with no mention of USB 2. I think they list that on some SKUs simply as a convenience.

author: tooki
author_rank: Super Contributor
timestamp: January 16, 2024, 11:09:39 am
content: Quote from: Ogitek on January 16, 2024, 09:56:09 amThey don’t say any of that. What they say is how to choose LEMO connectors that they know work well.Note that in that datasheet, when they say “proprietary interface” as the insert type, they mean “LEMO design, not an open standard”, NOT that it was designed specifically for USB!I think you really need to a) relax before you have a seizure from how much you’re overthinking this, and b) listen to the folks who’ve given you more than enough information to have solved this issue days ago. I’m not really sure why this discussion is even still ongoing.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 16, 2024, 12:06:20 pm
content: Quote from: tooki on January 16, 2024, 10:51:51 amYes, there is mentioned of USB 2.0. In fact, only the 304 spec sheet has the following lines added "Differentiated pairs (High Speed) 1 Protocol: USB 2.0 (480Mbps)", the rest doesn't have the lines:So is it only because there are 4 pins or the pins are some kind of alloys?In fact, some believe that Lemo connectors are for audio, not half-GHz RF. So you need special material to do that. "Generic" Lemo connectors were originally NOT meant for high frequencies. They were used for DC or low-frequency measurements where you typically don't have to worry about the impedance but you need a rugged, reliable connector. Note that Lemo was selling the exact same type of connector well before USB was even a thing.So does the 4 pin configuration use special metal that can change the impedance?I don't just need 1 cable, but many in our production business where we only loan so we want to make sure we made the right investments.

author: tooki
author_rank: Super Contributor
timestamp: January 17, 2024, 08:05:43 pm
content: Quote from: Ogitek on January 16, 2024, 12:06:20 pmYou're reading and quoting me selectively, missing the point.I said: "...if you look at their overall catalog, '304' is one of their standard insert sizes, with no mention of USB 2."Theoverallcatalog, not the individual datasheets, not the high-speed data guide, but thegeneral catalog. It lists insert layout 304, but never mentions USB. (Admittedly, "overall" was not the clearest choice of word.)I checked an old LEMO catalog that predates USB 2.0 and guess what? Insert 304 is already there, because it's been there for decades.If you check the high-speed data guide, you will notice that only connector sizes 0 and 1 are recommended for USB 2, despite the fact that the "304" layout exists in almost every size of connector they have, too, both larger and smaller than 0 and 1.Quote from: Ogitek on January 16, 2024, 12:06:20 pmIt's obvious that you don't even know what characteristic impedanceis, so there's no point in you speculating on how they achieve it.Especially since the answer is: they don't do anything special for USB 2. They simply recommend for USB 2.0 theexisting4-pin connectors whose insert dimensions best match the needs of USB 2.0. Characteristic impedance is fundamentally defined by the properties of the dielectric (which is always PEEK in these series) and the dimensions of the dielectric and the conductors. Since the parts they recommend for USB 2 existed long before USB 2, they clearly did not design special inserts because that would have required a time machine.Quote from: Ogitek on January 16, 2024, 12:06:20 pmPeople can believe whatever they want, that doesn't make them right. LEMO's most widespread use is laboratory equipment, especially in nuclear physics (which is one reason they use PEEK so much: it doesn't degrade nearly as much in radiation as other plastics -- they even talk about this in the catalog). But that isn't to say that LEMO doesn't have "widespread" use in various niches. (I mean, as widespread as extremely expensive connectors can be...)500MHz is notthathigh (my boss's boss at the physics department where I used to work always said "to me, anything under around 3GHz is just DC!") in the grand scheme of things. High enough to need to take care, but not as demanding as multi-GHz stuff. (Nuclear physics equipment still uses tons of LEMO coaxial connectors, which are noticeably inferior to the better "mainstream" coaxial connectors like SMA, according to said boss's boss.)The audiophile world has an uncanny knack for latching onto a kernel of truth about physical or electrical reality and then grossly misapplying it in nonsensical ways. So it's not worth following what they do. There is no performance reason to use LEMO in anything audio; it's just robustness and prestige.Quote from: Ogitek on January 16, 2024, 12:06:20 pmIf the clones match the pin and shell sizes of the originals (which they kinda have to to make them compatible) and used the correct insulator (PEEK) and dimensions, then they'll necessarily be very close to the originals' impedance profile.Quote from: Ogitek on January 16, 2024, 12:06:20 pmYep, that's what I said a while ago.Quote from: Ogitek on January 16, 2024, 12:06:20 pmThey don't, and it couldn't affect it in any significant way.Quote from: Ogitek on January 16, 2024, 12:06:20 pmSo you should really be paying a consultant rather than dicking around in a forum where you just talk in circles anyway.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 18, 2024, 07:10:30 am
content: Thanks for your convincing exposition.But what about USB 3.1? The old ordinary LEMO connectors with the respective numbers of pins matching USB 3.1 can also transmit at 5Gbps without significant reflections that can render it null?What speed when the average LEMO connectors can no longer catch up? I want to be ready in case I can get some old used Lucasfilm, etc. gears that may work at USB 3.1 and they used Lemo too.For reference: