Speakerplans.com Homepage
Forum Home Forum Home > General > General Forum
  New Posts New Posts RSS Feed - yet another laptop noise problem - hdmi
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

yet another laptop noise problem - hdmi

 Post Reply Post Reply Page  123>
Author
Message
godathunder View Drop Down
Old Croc
Old Croc


Joined: 19 July 2004
Location: wicklow
Status: Offline
Points: 1833
Post Options Post Options   Thanks (0) Thanks(0)   Quote godathunder Quote  Post ReplyReply Direct Link To This Post Topic: yet another laptop noise problem - hdmi
    Posted: 04 February 2019 at 12:56pm
mutter mutter shite switchmode psu noise crap mutter mutter

my problem is that my laptop is dumping its unwanted noises into my hifi

its the usual problem, fine on battery. fizzes, pops, hums and buzzes with the psu connected - present with all psus tried - disappears if I do the naughty thing with the earth disconnected (put your swords away gentlemen, it was done for test purposes only)

isolation transformers would be lovely but:

my problem is that Im connecting via hdmi

has anyone come across a hdmi isolation solution?

or I may just build a proper heavy metal psu and see if that improves matters


Edited by godathunder - 04 February 2019 at 12:58pm
LOUDER THAN LOUD
Back to Top
toastyghost View Drop Down
The 10,000 Points Club
The 10,000 Points Club
Avatar

Joined: 09 January 2007
Location: Manchester
Status: Offline
Points: 10920
Post Options Post Options   Thanks (0) Thanks(0)   Quote toastyghost Quote  Post ReplyReply Direct Link To This Post Posted: 04 February 2019 at 1:00pm
Your laptop is double insulated anyways and doesn’t need an earth. If nobody else is gonna use it then remove away.
Back to Top
godathunder View Drop Down
Old Croc
Old Croc


Joined: 19 July 2004
Location: wicklow
Status: Offline
Points: 1833
Post Options Post Options   Thanks (0) Thanks(0)   Quote godathunder Quote  Post ReplyReply Direct Link To This Post Posted: 04 February 2019 at 1:03pm
point taken but it feels like the wrong solution

Im obviously looking for a way of further complicating my life
LOUDER THAN LOUD
Back to Top
cravings View Drop Down
Old Croc
Old Croc
Avatar

Joined: 30 January 2007
Location: Ireland
Status: Offline
Points: 7441
Post Options Post Options   Thanks (0) Thanks(0)   Quote cravings Quote  Post ReplyReply Direct Link To This Post Posted: 04 February 2019 at 1:18pm
i'm sure that answers your question.
Back to Top
dylan-penguinmedia View Drop Down
Old Croc
Old Croc
Avatar

Joined: 14 April 2011
Location: Brighton
Status: Offline
Points: 4576
Post Options Post Options   Thanks (0) Thanks(0)   Quote dylan-penguinmedia Quote  Post ReplyReply Direct Link To This Post Posted: 04 February 2019 at 1:20pm
Originally posted by cravings cravings wrote:

i'm sure that answers your question.

LOL
Back to Top
godathunder View Drop Down
Old Croc
Old Croc


Joined: 19 July 2004
Location: wicklow
Status: Offline
Points: 1833
Post Options Post Options   Thanks (0) Thanks(0)   Quote godathunder Quote  Post ReplyReply Direct Link To This Post Posted: 04 February 2019 at 1:21pm
Originally posted by efinque efinque wrote:

At a venue I used to DJ and host karaoke there's a micro-USB to HDMI adapter via an Ethernet/RJ45 from a tablet to the main system which is used for the AV signal (the distance between the tablet and the booth is about 20m)

Sometimes the cable/adapter (which also supplies power to the tablet) gets loose which cuts the signal.

thank you efinque, thats very kind of you but possibly not entirely pertinent to my problem
LOUDER THAN LOUD
Back to Top
godathunder View Drop Down
Old Croc
Old Croc


Joined: 19 July 2004
Location: wicklow
Status: Offline
Points: 1833
Post Options Post Options   Thanks (0) Thanks(0)   Quote godathunder Quote  Post ReplyReply Direct Link To This Post Posted: 04 February 2019 at 1:34pm
audio + video output required hence hdmi

Ive got a couple of those cheap little behringer usb interfaces for 2ch audio needs
LOUDER THAN LOUD
Back to Top
kedwardsleisure View Drop Down
Old Croc
Old Croc


Joined: 20 January 2009
Location: Staffordshire
Status: Offline
Points: 4938
Post Options Post Options   Thanks (0) Thanks(0)   Quote kedwardsleisure Quote  Post ReplyReply Direct Link To This Post Posted: 04 February 2019 at 2:02pm
If the laptop adapter has an earth then it's there for a reason, it's using it to provide the barrier between mains and low voltage output. So don't remove it. A class 1 psu is also allowed to leak alot more current to earth than a class 2 psu and with the earth lifted that leakage is going to present itself on any exposed conductor on or connected to the laptop.

I would look around to see if there's a double insulated power supply option (these used enhanced pri-sec insulation), the sort that uses a figure-8 mains lead. It's no guarantee of being noise free but it's got to be worth a try, I know clients that have had success with it in karaoke with multiple TVs.

I'm sure you can get an HDMI isolator but I bet they're dear.



Kevin

North Staffordshire

Back to Top
godathunder View Drop Down
Old Croc
Old Croc


Joined: 19 July 2004
Location: wicklow
Status: Offline
Points: 1833
Post Options Post Options   Thanks (0) Thanks(0)   Quote godathunder Quote  Post ReplyReply Direct Link To This Post Posted: 04 February 2019 at 2:24pm
I think a rummage round the spares boxes is in order. Ill see if I can knock up a suitable 19v/70w wirewound psu out of the parts Ive got lying round and some minimal ordering. 

will be interesting to see if it provides a solution

Ill add it to the to do list and report back with results at some distant point
LOUDER THAN LOUD
Back to Top
kedwardsleisure View Drop Down
Old Croc
Old Croc


Joined: 20 January 2009
Location: Staffordshire
Status: Offline
Points: 4938
Post Options Post Options   Thanks (0) Thanks(0)   Quote kedwardsleisure Quote  Post ReplyReply Direct Link To This Post Posted: 04 February 2019 at 2:54pm
that's going to be a hell of a linear power supply! It'll need to use a switching regulator to get that sort of current without a heatsink the size of a potato waffle
Kevin

North Staffordshire

Back to Top
outkast View Drop Down
Registered User
Registered User


Joined: 23 September 2010
Status: Offline
Points: 66
Post Options Post Options   Thanks (0) Thanks(0)   Quote outkast Quote  Post ReplyReply Direct Link To This Post Posted: 04 February 2019 at 3:37pm
May or may not be relevant, but I had a noise problem with an Apple Macbook 2012 which had a slightly different power supply to my older 2006 Macbook. The noise went away when I used the older power supply on the newer laptop, so the issue was definitely with the power supply.
Back to Top
concept-10 View Drop Down
Young Croc
Young Croc


Joined: 17 May 2016
Status: Offline
Points: 1292
Post Options Post Options   Thanks (0) Thanks(0)   Quote concept-10 Quote  Post ReplyReply Direct Link To This Post Posted: 04 February 2019 at 4:08pm
Originally posted by cravings cravings wrote:

i'm sure that answers your question.

Fully sorted Wink
Back to Top
 Post Reply Post Reply Page  123>

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.06
Copyright ©2001-2023 Web Wiz Ltd.

This page was generated in 0.125 seconds.