EEVbog 1613 -Audiophile REPAIR: Chord Hugo DAC - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: May 03, 2024, 06:48:56 am
content: Simple repair on the neighbours $4500 Audiophile Chord Hugo DAC.Replacing the rechargeable lithium ion batteries wasn't quite as simple as expected though...And is this thing worth $4500?

author: wraper
author_rank: Unknown
timestamp: May 03, 2024, 07:28:14 am
content: And still too cheap to put a battery connector.

author: SiliconWizard
author_rank: Super Contributor
timestamp: May 03, 2024, 10:09:54 pm
content: Would have liked a full teardown. We don't see much of it at all, so hard to tell how it's really designed, apart from the two batteries and the Bluetooth module, which, btw, is from a (now dead) finnish company, none of this Espressif junk.I don't know how old the design of this DAC product is though - Bluegiga has been acquired by SiLabs, and I doubt this module is still current (there's much better in the SiLabs offering directly these days, and I don't know if they still sell the legacy Bluegiga stuff).

author: themadhippy
author_rank: Super Contributor
timestamp: May 03, 2024, 11:02:41 pm
content: QuoteHave you seen the price of audifool grade battery connectors

author: temperance
author_rank: Super Contributor
timestamp: May 03, 2024, 11:31:05 pm
content: If what you saw with the one shorted battery terminal is true, than this product has a serious flaw because the protection circuits within the batteries will open/close in a random order.

author: Exosia
author_rank: Contributor
timestamp: May 04, 2024, 06:13:00 am
content: Quote from: wraper on May 03, 2024, 07:28:14 amconnectors will introduce noise

author: Samuel
author_rank: Newbie
timestamp: May 04, 2024, 12:51:25 pm
content: I think i know why the battery was acting weird:You damaged the insulation on the battery negative cable close to the wifi module when you used the yellow plastic spatula at 10:20 in the video.I have a big screen and can see individual strands of silver wire starting at 10:46.It also looks like you damaged the insulation on the positive wire when you pinned it down with the tweezers at 11:17, i can see a silver spot in the middle of the cable at 10:22.While doing this you might also have produced a short between the positive wire and the through hole pad below it, which would have triggered the protection circuit. After you let go of the wire the short was removed and the battery protection circuit could recover.At 12:15 i can count three strands of wire in the negative cable, i attached a zoomed in screenshot to this post.I can also see some silver in the red cable.

author: coppice
author_rank: Super Contributor
timestamp: May 04, 2024, 12:57:25 pm
content: Quote from: Samuel on May 04, 2024, 12:51:25 pmI was puzzled that he took out the batteries and then desoldered, but put the batteries in before soldering the contacts. I would have soldered the contacts with the batteries out, giving me lots of room, and then slipped them into place.

author: wraper
author_rank: Unknown
timestamp: May 04, 2024, 01:00:52 pm
content: Quote from: coppice on May 04, 2024, 12:57:25 pmTo be fair, if you solder with batteries outside, you then may find that wires are of the wrong length or you need to bend them awkwardly.

author: coppice
author_rank: Super Contributor
timestamp: May 04, 2024, 01:04:29 pm
content: Quote from: wraper on May 04, 2024, 01:00:52 pmHe did have a role model for lengths that would work well in the batteries he took out.

author: elektryk
author_rank: Regular Contributor
timestamp: May 06, 2024, 03:36:43 pm
content: Quote from: SiliconWizard on May 03, 2024, 10:09:54 pmI was also sceptical about ESP32 but it turned out that running BT I2S sink was so easy with open source libraries.There are modules dedicated strictly for BT audio such as QCCxxxx but without public documentation and SDK...

author: golden_labels
author_rank: Super Contributor
timestamp: May 06, 2024, 09:31:04 pm
content: How did the neighbour react to being considered an audiofool?

author: jnissen
author_rank: Regular Contributor
timestamp: May 07, 2024, 03:27:17 pm
content: Quote from: golden_labels on May 06, 2024, 09:31:04 pmI'm sure Dave will have to live that down later!

author: syzygy
author_rank: Contributor
timestamp: May 07, 2024, 07:21:26 pm
content: I'd guess the battery can is actually shorting to the product's case (and not a reliable short).Keep in mind, this uses 2 batteries for a reason - bi-polar rails (quiet ones)Both batteries have a negative can (I think), and the obvious connection for the batterie is spilt around common.So, one battery may be allowed to touch the case but not BOTH.... and if the case isn't 'floating', then even one battery touching the case will be as short circuit.-it may come back, and soon.intermittent faults can cause confusion

author: EEVblog
author_rank: Unknown
timestamp: May 07, 2024, 11:39:10 pm
content: Quote from: golden_labels on May 06, 2024, 09:31:04 pmHe also thinks they are stupidly expensive, hence why he got it cheap 2nd hand.

author: EEVblog
author_rank: Unknown
timestamp: May 07, 2024, 11:40:12 pm
content: Quote from: wraper on May 04, 2024, 01:00:52 pmCorrect. I've bene burned by this too many times, so it's just a habbit to fit first then solder.

author: Greybeard
author_rank: Frequent Contributor
timestamp: May 13, 2024, 04:23:36 pm
content: Dave, I'm quite sure that you can do it much better than here in the video (soldering).Sorry...

author: EEVblog
author_rank: Unknown
timestamp: May 13, 2024, 11:08:16 pm
content: Quote from: Greybeard on May 13, 2024, 04:23:36 pmWhat was wrong with the solder joints?

author: rsjsouza
author_rank: Super Contributor
timestamp: May 14, 2024, 12:07:04 am
content: To me the PCB design has the plus and minus pads so close to each other that it is a major fail - a catastrophe waiting to happen.

author: EEVblog
author_rank: Unknown
timestamp: May 14, 2024, 01:13:58 am
content: Quote from: rsjsouza on May 14, 2024, 12:07:04 amIt's certainly not ideal. But once carefully soldered in place it's no problem really. Also the proximity to the metal case above, not much clearance. I put some tape over the connections just in case.

author: Greybeard
author_rank: Frequent Contributor
timestamp: May 14, 2024, 05:19:08 am
content: Quote from: EEVblog on May 13, 2024, 11:08:16 pmCome on... you know it.I think just a bit too little solder, too many attempts with too little flux, not enough "shine"...Don't the joints look a bit ugly?

author: syzygy
author_rank: Contributor
timestamp: May 14, 2024, 04:50:49 pm
content: Quote from: EEVblog on May 14, 2024, 01:13:58 amYou should have put tape over where the battery wrapper got cut.I know you said that the battery cases are negative, but NOT IN THIS SITUATION! With a dual-rail derived from 2 batteries, the CASE on ONE of those batteries is going to ACTUALLY be the -3.3V rail for the circuit.-and if THAT battery's case touches the aluminum housing (like that one did when it got sliced) you will have a short circuit.I'm suggesting THAT is what might have happened with the fault you saw.

author: thm_w
author_rank: Super Contributor
timestamp: May 14, 2024, 08:01:18 pm
content: Quote from: syzygy on May 14, 2024, 04:50:49 pmAgree you'd have a short if it cut through fully, though, the battery wrapper is: a sticker, heatshrink outer layer, and another heatshrink inner layer. Unlikely you'd cut through all of those layers without decent force. When he inserts the battery at 11:30 and pushed it in, there was still voltage on it, indicating no short had been made.Quote from: Greybeard on May 14, 2024, 05:19:08 amLooks good enough to me. No shine is due to lead-free solder.

author: SiliconWizard
author_rank: Super Contributor
timestamp: May 14, 2024, 09:15:07 pm
content: In french, we call that "inspecteur des travaux finis". There's always a herd of them on social media.

author: EEVblog
author_rank: Unknown
timestamp: May 15, 2024, 03:36:01 am
content: Quote from: Greybeard on May 14, 2024, 05:19:08 amNope, they are fine.Lead free solder, lighting and camera exposure can make anything look like anything.