out put problems

timwebb · 29th January 2010, 12:11 AM

what would cause an amp to hum is it to much current,even with no music playing?

sakis · 29th January 2010, 10:51 AM

bad wiring , earth loops, a connection with a lap top or PC , problems inside the amp hardware related loose contacts , unisoltaed plugs , problems in the rectifier board , various forms of abuse , secondary psu issues if exist , the weather , the political party you voted last year , and your last night's meal ....

h_a · 29th January 2010, 11:01 AM

If the wiring scheme is ok, its usually the transformer being too close to the amp-boards.

Most DIYers build however big enclosures, so that seems to happen only rarely.

If it's the wiring scheme, you need to give more details

Have fun, Hannes

PS: Sakis, did you really had one occasion where you could hear rectifier noise from the speakers? I'm just curious as in my experience everything else is so much bigger.

sakis · 11:25 AM

Yes i did ....also problems like that are by far more obvious when you have to do with preamps .... so amplifiers are the same thing only gain and signal levels are nto the same

Mooly · 29th January 2010, 11:51 AM

Is it hum ?... 50/60 hz fundamental which is a very pure LF tone, or a much harsher 100/120 hz "buzz" with harmonics ?
That's a vital clue as to what the problem is.

AndrewT · 29th January 2010, 11:54 AM

Hi,
is the hum a mechanical hum from the amplifier case, or an electrical signal hum coming from the speaker cone?

29th January 2010, 12:11 AM	#1
timwebb diyAudio Member Join Date: Jan 2010 Location: memphis tn	out put problems what would cause an amp to hum is it to much current,even with no music playing?

29th January 2010, 10:51 AM	#2
sakis diyAudio Member Join Date: Jan 2006 Location: nea makri athens greece	bad wiring , earth loops, a connection with a lap top or PC , problems inside the amp hardware related loose contacts , unisoltaed plugs , problems in the rectifier board , various forms of abuse , secondary psu issues if exist , the weather , the political party you voted last year , and your last night's meal .... __________________ SERVICE ΕΝΙΣΧΥΤΩΝ ΚΑΙ ΙΑΠΩΝΙΚΩΝ ΜΗΧΑΝΗΜΑΤΩΝ ΗΧΟΥ www.eastelectronics.gr

29th January 2010, 11:09 AM	#4
sakis diyAudio Member Join Date: Jan 2006 Location: nea makri athens greece	Yes i did ....also problems like that are by far more obvious when you have to do with preamps .... so amplifiers are the same thing only gain and signal levels are nto the same __________________ SERVICE ΕΝΙΣΧΥΤΩΝ ΚΑΙ ΙΑΠΩΝΙΚΩΝ ΜΗΧΑΝΗΜΑΤΩΝ ΗΧΟΥ www.eastelectronics.gr Last edited by sakis; 29th January 2010 at 11:25 AM.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
where should I put the tweeters?	PeteMcK	Multi-Way	7	27th July 2007 04:33 AM
Looking for someone to put a crossover together for me	Xristo	Multi-Way	11	3rd August 2005 08:39 AM
Out Put Transistors	RaidersGuy	Solid State	0	12th February 2005 07:47 PM
I've put loadlines aside for a while...	Mikael Abdellah	Tubes / Valves	22	5th May 2003 07:17 PM


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

29th January 2010, 11:01 AM	#3
h_a diyAudio Member Join Date: Sep 2006 Location: Graz, Austria	If the wiring scheme is ok, its usually the transformer being too close to the amp-boards. Most DIYers build however big enclosures, so that seems to happen only rarely. If it's the wiring scheme, you need to give more details Have fun, Hannes PS: Sakis, did you really had one occasion where you could hear rectifier noise from the speakers? I'm just curious as in my experience everything else is so much bigger.

29th January 2010, 11:51 AM	#5
Mooly diyAudio Moderator Join Date: Sep 2007	Is it hum ?... 50/60 hz fundamental which is a very pure LF tone, or a much harsher 100/120 hz "buzz" with harmonics ? That's a vital clue as to what the problem is.

29th January 2010, 11:54 AM	#6
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	Hi, is the hum a mechanical hum from the amplifier case, or an electrical signal hum coming from the speaker cone?

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read