Sketchy claim from audiophoole brand Audioquest - Page 1
Forum section: electronics / general

author: JonHendry
author_rank: Contributor
timestamp: August 31, 2018, 04:56:43 am
content: So Audioquest, of the overpriced magic ethernet and HDMI cables, has a USB DAC called the Dragonflyhttps://www.audioquest.com/dacs/dragonfly/dragonfly-redAmong the marketing spiel for it is this bit, which I find hard to believe:QuoteIs it just me, or does anyone else think Microchip probably didn't need to collaborate with an outfit like Audioquest to design a new microcontroller?Also, they have a $50 USB noise filter called the "jitterbug":QuoteAnd there's this gem: "Use an additional JitterBug in parallel for improved playback performance."As in, "plug a second one into the empty USB socket next to the socket you're using for your DAC, which is connected through a Jitterbug."And: "Use JitterBug with other locally connected USB devices, such as hard drives, printers, and cameras, to effectively reduce audio interference."And: "Use JitterBug with USB-enabled network devices, such as routers, NAS devices, and streamers."Very important to filter that USB port on the router that you're not using.It's small enough that I wonder if there's anything in it at all.

author: glarsson
author_rank: Frequent Contributor
timestamp: August 31, 2018, 08:02:33 am
content: It could be a capacitor between +5V and ground. Then it would "make sense" to add more devices in other USB ports nearby. :-)

author: gedong
author_rank: Contributor
timestamp: September 01, 2018, 04:57:44 am
content: or maybe galvanic isolation ? it's usefull for reducing any EMI / RF.don't know about jitter though.

author: Bud
author_rank: Super Contributor
timestamp: September 01, 2018, 05:09:27 am
content: PIC32MX is a general purpose type microcontroller family and was introduced quite a few years ago.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 01, 2018, 12:58:34 pm
content: I'm surprised they didn't use a PIC32MZ for USB 2.0 and 192kHz support.

author: Cyberdragon
author_rank: Super Contributor
timestamp: September 01, 2018, 01:45:58 pm
content: Quote from: NiHaoMike on September 01, 2018, 12:58:34 pmNo, it has to be USB 1.0 because 2.0 is too fast and stresses your audio electrons. It has to be super slow to properly escort the electons to their destination without discombobulating them. Otherwise , you must have the 10K cable and filter to align and orient the electrons in the right direction so they can be quantum reencabulated.Don't even ask what it takes to reencabulate 3.0...

author: amyk
author_rank: Super Contributor
timestamp: September 02, 2018, 10:13:48 pm
content: Quote from: glarsson on August 31, 2018, 08:02:33 amYes, I suspect they're just bulk decoupling caps. Not true snake-oil but probably not much benefit either. Weird "power filtering" products have been around for many years:https://www.ixbt.com/news/hard/index.shtml?10/66/54I suspect they will show an effect only if your existing filter caps are already too dried-out to be of much use.

author: ebastler
author_rank: Super Contributor
timestamp: September 03, 2018, 10:53:42 am
content: Quote from: JonHendry on August 31, 2018, 04:56:43 amIf you read carefully, the quote does not say that Microchip got any input from Gordon Rankin and Audioquest. Gordon worked "alongside Microchip", which seems to mean that he used their new chip in his circuit design. The new PIC draws 77% less current (but Gordon presumably had nothing to do with that), and Gordon made "significant contributions to AudioQuest" (but probably none to Microchip).A nice example of marketing weasels at work...

author: newbrain
author_rank: Super Contributor
timestamp: September 03, 2018, 12:31:05 pm
content: Quote from: amyk on September 02, 2018, 10:13:48 pmL(?)C decoupling on the power lines and a common mode choke on the data lines.As the product is not new, there's discussion aplenty on it online.

author: Domagoj T
author_rank: Frequent Contributor
timestamp: September 04, 2018, 06:23:58 am
content: Quote from: ebastler on September 03, 2018, 10:53:42 amI wonder if Microchip appreciates being mentioned in this context at all.

author: schmitt trigger
author_rank: Super Contributor
timestamp: September 04, 2018, 07:18:54 am
content: It may be a flux capacitor

author: RobK_NL
author_rank: Frequent Contributor
timestamp: September 06, 2018, 11:38:32 am
content: QuoteI.e. he was so out of his depth that he had to continually pester Microchip's FAE's to get a working product.

author: bob225
author_rank: Frequent Contributor
timestamp: September 06, 2018, 11:46:51 am
content: QuoteOh yes he printed out the pdf datasheet and had it on his desk

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 06, 2018, 08:46:51 pm
content: Quote from: JonHendry on August 31, 2018, 04:56:43 amTranslation: he posted a question on their forum once.

author: Halcyon
author_rank: Unknown
timestamp: September 14, 2018, 03:45:25 am
content: Quote from: Ice-Tea on September 06, 2018, 08:46:51 pmOr he parked his car outside their building, drew a doodle and called it "work".

author: mc172
author_rank: Frequent Contributor
timestamp: September 19, 2018, 10:50:31 pm
content: Quote from: gedong on September 01, 2018, 04:57:44 amGalvanic isolation is absolutely not useful for reducing EMI!

author: langwadt
author_rank: Super Contributor
timestamp: September 19, 2018, 11:08:51 pm
content: Quote from: glarsson on August 31, 2018, 08:02:33 amUSB 2.0 specification limits capacitance on Vbus to 10uF to limit inrush current

author: glarsson
author_rank: Frequent Contributor
timestamp: September 20, 2018, 07:28:06 am
content: Quote from: langwadt on September 19, 2018, 11:08:51 pmFacts and specifications will not stop an audiofool company.

author: MrMobodies
author_rank: Super Contributor
timestamp: November 05, 2018, 06:43:19 pm
content: I hear all sorts of noises from different sound cards but they don't seem to bother me that much.Sometimes it can be quite soothing.