USB upgrader for audio ??? - Page 1
Forum section: electronics / general

author: rob77
author_rank: Super Contributor
timestamp: March 04, 2022, 12:17:42 pm
content: what the actual frac ?https://www.aliexpress.com/item/4000265006089.htmlwhat is it supposed to do ? except taking the simpleton buyer's money of course

author: Haenk
author_rank: Super Contributor
timestamp: March 04, 2022, 01:05:29 pm
content: This is just a PCB full of different caps. Not sure, if actually electrically connected to the USB plug at all. But sure of one thing: It does not matter.You might want to check this out:https://linustechtips.com/topic/1192680-do-these-pcie-capacitor-card-things-do-anything/

author: rob77
author_rank: Super Contributor
timestamp: March 04, 2022, 03:21:02 pm
content: i know it's a bunch of capacitors.. even if considered as "extra decoupling" it makes no effect... but i would be curious what's the "official explanation"

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 04, 2022, 06:11:58 pm
content: Good lord.And seeing your pic and given it's on Aliexpress, I was at least expecting something cheap. But not even so.That raises a new trend: while most sellers on Aliexpress used to sell cheap stuff at low prices, ever since the inflation - allegedly due to semiconductor shortage, but that many have taken as an opportunity - you now find a lot of chinese sellers that have switched behaviors and sell stuff for ridiculously high prices - sometimes even higher than from western distributors. But hey, if there are people gullible enough to buy, why would they not...

author: AVGresponding
author_rank: Super Contributor
timestamp: March 04, 2022, 07:39:27 pm
content: Well, they need to make as much profit as they can, to cover all the bad Russian government debt they are about to take on...

author: MrMobodies
author_rank: Super Contributor
timestamp: March 05, 2022, 02:12:10 am
content: https://www.gonetpc.com/Item/585845423922Fever USB 3 0 audio-visual upgradercontains natural crystalUU004MKII decoder power amplifier purifierQuoteWhat a cheap flimsy looking case.I don't see any crystal and what good is that going to do?

author: Haenk
author_rank: Super Contributor
timestamp: March 05, 2022, 02:26:10 pm
content: Quote from: MrMobodies on March 05, 2022, 02:12:10 amHaha, you are thinking way too EE-style.By "crystal", they really mean "crystal". All those transparent little glass-type thingies (is it quartz or glass or just some random recycled plastics waste?) rattling around in this little case *will* surely make a difference (in your wallet).

author: Nominal Animal
author_rank: Super Contributor
timestamp: March 05, 2022, 03:47:23 pm
content: Dogdammit these ripoffs!I know of exactly one use case for adding bulk capacitance to USB, like the 2mF oneOlimex sells.It is when using devices like cellular modems that temporarily or in peaks consume a lot of current (average below 500mA or so), on devices like SBCs or routers that just do not have sufficient bulk capacitance on that 5V USB rail to deal with that. It used to be a problem in the 3G era, because those modems just gulped current. (Olimex mentions 2A during initialization.)In the 4G/LTE era, the bigger issue is that too many of the USB-WWAN adapters use linear regulators instead of DC-DC converters, and those linear regulators get too hot. They often also use 3.3V regulators, whereas the M.2 form factor modems (using only the USB and SIM card lines) typically prefer 3.8 to 4.2 V. With a proper DC-DC converter at proper voltage, the modems I've used (Huawei ME909s-120, MikroTik R11e-LTE) seem to do absolutely fine even with larger antennas. No added USB bulk capacitance needed.

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 05, 2022, 09:40:09 pm
content: Note that directly putting a large capacitor on the VBUS line is absolutely non-compliant with the USB standard. It will create a gigantic inrush current when plugged in. How the host will react completely depends on how its USB ports are implemented, but in any case, it is not compliant with USB whatsoever. Laptops in general will just shut the port off.There are ways to circumvent that, but they take some additional hardware and a bit of forethought. I bet many of those solutions do not have either.

author: Nominal Animal
author_rank: Super Contributor
timestamp: March 05, 2022, 10:16:07 pm
content: Quote from: SiliconWizard on March 05, 2022, 09:40:09 pmTrue! (Neither were the first 3G modems, btw.) On the affected SBCs, the USB +5V was directly connected to a regulator, which simply was not able to deal with spiky current draw, and browned out. On my Odroid-HC1, itisthe input rail (it only takes a single +5V input at 2A-6A, depending on what is loaded on that +5V rail). With current or previous-generation 4G/LTE modems, no such shenanigans are needed; they have the circuitry on board to smooth out their current draw sufficiently.Which makes the linked USB things doubly annoying: they havejustenough of an actual historical use case in them that those not too gone in the Audiophool realm but without any grasp of the technical aspects, can get mislead (by careless Googling) into thinking "maybe there is something here after all". There isn't. Nobody needs or wants added bulk capacitance on their USB bus. Therewasone specific nonstandard use case that one can find references to, but even it does not apply anymore.