|
Bad audio noise on macbook pro |
Post Reply 
|
| Author | |
subbass 
Old Croc 
Joined: 30 March 2009 Location: bristol Status: Offline Points: 1683 |
 Post Options
 Thanks(0)
 Quote Reply
 Topic: Bad audio noise on macbook proPosted: 05 January 2010 at 8:45pm |
|
Hi all
got a wee problem with the MBP, and I think you guys may be able to help  The internal soundcard has issues driving low impedance (hifi!) amplifiers, it cranks out noise almost equal to the volume of the music at full blast  Is there anyway to lower the impedance of the input to the amplifier? Its a shielded minijack -> RCA connection .. ground loop thing? resistors? potentiometer? Dont really want to buy an ext. soundcard :/ Thanks
Edited by subbass - 05 January 2010 at 8:54pm |
|
 |
|
|
subbass
Old Croc
Joined: 30 March 2009 Location: bristol Status: Offline Points: 1683 |
Post Options
Thanks(0)
Quote Reply
Posted: 05 January 2010 at 8:54pm |
|
|
|
jonminns
Old Croc
Joined: 13 April 2008 Location: United Kingdom Status: Offline Points: 1877 |
Post Options
Thanks(0)
Quote Reply
Posted: 05 January 2010 at 10:33pm |
|
sounds like you've been unlucky and got an iffy one, the internal soundcard on mine is better than the serato boxes!
|
|
|
4 ohms is for wimps
|
|
|
|
|
subbass
Old Croc
Joined: 30 March 2009 Location: bristol Status: Offline Points: 1683 |
Post Options
Thanks(0)
Quote Reply
Posted: 05 January 2010 at 10:38pm |
|
yeah, apple are notorious for bad batches here and there.. (QC doesnt seem to be that great all the time)
ill give applecare a call tomorrow
 |
|
|
|
|
Saul
Old Croc
Joined: 15 June 2007 Status: Offline Points: 5912 |
Post Options
Thanks(0)
Quote Reply
Posted: 05 January 2010 at 10:43pm |
|
really??
|
|
|
|
|
Lyndon A
Registered User 
Joined: 15 November 2004 Location: Bristol Status: Offline Points: 536 |
Post Options
Thanks(0)
Quote Reply
Posted: 05 January 2010 at 10:51pm |
|
Try headphones on it, whats it sound like then?
|
|
|
FSV Sounds
|
|
|
|
|
toastyghost
The 10,000 Points Club 
Joined: 09 January 2007 Location: Manchester Status: Offline Points: 10920 |
Post Options
Thanks(0)
Quote Reply
Posted: 05 January 2010 at 10:53pm |
|
Are you sure you've not just damaged the socket somehow, such as pulling a 3.5mm jack at odd angles to the casing?
I've not heard of any 'common' issues with MacBook nor MacBook Pro internal soundcards. |
|
|
|
|
subbass
Old Croc
Joined: 30 March 2009 Location: bristol Status: Offline Points: 1683 |
Post Options
Thanks(0)
Quote Reply
Posted: 05 January 2010 at 10:56pm |
|
yeah, you wont believe the number of little issues I've had with various products of theirs - my iMac G5 had loads of little 'bugs', all firmware or hardware based. Then again it was practically a prototype
 Bit p*ssed to spend this much on a damn computer for it not to be able to play audio consistently! ps. About the bad batches, you obviously have never had to go onto their support forums  ! |
|
|
|
|
subbass
Old Croc
Joined: 30 March 2009 Location: bristol Status: Offline Points: 1683 |
Post Options
Thanks(0)
Quote Reply
Posted: 05 January 2010 at 11:00pm |
Believe me, its not the cable or the socket :( The noise starts when you turn the volume from MUTE to the lowest setting, even when nothing is output! Ie, when the internal circuitry is turned on The amp works fine with every other source, pc mixer or ipod... I found some stuff on the internet about impedence issues in some other macbooks, hence me taking this direction
 |
|
|
|
|
b3n
Registered User
Joined: 28 September 2008 Location: Brighton, UK Status: Offline Points: 222 |
Post Options
Thanks(0)
Quote Reply
Posted: 11 January 2010 at 5:07pm |
|
If its a grounding loop issue its usually much louder when the charger is attached. Doesn't sound like what your experiencing though.
|
|
|
Matrix XP3000H, Thomann TA1050, Peavey CS1400, QSC RMX1450
2 x Eminence Kappa and PSD2002 loaded x15's 2 x SN-15MB and BM-D450 loaded X15's 2 x V18-1000 loaded 1850's Behringer DCX2496 |
|
|
|
|
odc04r
Old Croc
Joined: 12 July 2006 Location: Sarfampton Status: Offline Points: 5483 |
Post Options
Thanks(0)
Quote Reply
Posted: 11 January 2010 at 5:23pm |
A hifi amp will have a relatively high input impedance, headphones are low impedance. Why do you think it has anything to do with the impedance of whats connected to it out of interest? If you're getting noise equal to the signal my professional opinion is that something is shagged. Need more details really. |
|
|
|
|
subbass
Old Croc
Joined: 30 March 2009 Location: bristol Status: Offline Points: 1683 |
Post Options
Thanks(0)
Quote Reply
Posted: 11 January 2010 at 6:45pm |
|
just wrote a gurt big reply then deleted it
turns out its an issue with some kind of internal gain in the soundcard. Its a firmware / hardware issue and is triggered by the low impedence presented by the amplifier, causing it to go haywire and triggering the static.. Was told the generic "use a ground loop isolator" by apple to sort the issue, but until they can have a look at it (not an option, need it for uni!) they cant do anything else. so, have ordered a USB soundcard - output wasnt all that clean anyway :)
|
|
|
|
|
Post Reply
|
|
| Tweet |
| Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |
Topic Options
toastyghost wrote: