Noisy Amp

vento · 13th January 2009, 08:15 PM

My amp makes a noise on power down (through the speakers). Anybody any ideas?

dave_gerecke · 13th January 2009, 08:19 PM

Hello Vento, more details would help a lot, kind of noise, make and model of amp. These will help others give you ideas as to whether it is a problem or not.

Peace,

Dave

lineup · 13th January 2009, 08:21 PM

This is quite normal.
And nothing to be very afraid of.
At power off the big electrolytic capacitors take some short time to dis-charge.

A way to avoid this would be to use an output relay.
This relay should immidiately disconnect speakers when OFF switch pressed.
This is probably how most commercial amplifiers do it.

Along with a delay to connect speakers at POWER ON.
To let everything get charged, settled and stable, before connect the speakers.
This will avoid any 'pop' sounds at power on.

vento · 14th January 2009, 10:27 AM

Hi,
Thanks for your replies so far. The amp is the Music Fidelity E10 and works fine other than this problem. I had thought on the lines of capacitor discharge, but this is not a short burst of sound, it sound more like an aircraft crashing! (not joking), and lasts about 5-6 seconds.

sakis · 14th January 2009, 01:04 PM

Quote:

Originally posted by lineup
This is quite normal.
And nothing to be very afraid of.
At power off the big electrolytic capacitors take some short time to dis-charge.

A way to avoid this would be to use an output relay.
This relay should immidiately disconnect speakers when OFF switch pressed.
This is probably how most commercial amplifiers do it.

Along with a delay to connect speakers at POWER ON.
To let everything get charged, settled and stable, before connect the speakers.
This will avoid any 'pop' sounds at power on.

i am very sory to say that there is no point to place an answer to a thread for the reason to just place one answer to a thread ......

i am surprized.... this is not like you at all .......

as far as i remember this amplifier does not feature a relay in the output .... i dont know the schematic but if this is some kind of trouble that occured now it might mean that during shut down your front stage comes out of balance ....

this will recuire a schematic to solve

sakis · 14th January 2009, 01:12 PM

Quote:

Originally posted by lineup
This is quite normal.this is not normal at all especially if its a problem that occured .... if amplifier is designed like that .... from starts it means that is a cheapy

And nothing to be very afraid of.if your speakers are small and high efficiency then a loud pop could cause a lot of damages if happen every day

At power off the big electrolytic capacitors take some short time to dis-charge.

A way to avoid this would be to use an output relay.
This relay should immidiately disconnect speakers when OFF switch pressed.
This is probably how most commercial amplifiers do it.

Along with a delay to connect speakers at POWER ON.
To let everything get charged, settled and stable, before connect the speakers.
This will avoid any 'pop' sounds at power on.

as about adding a relay in amp like that is something that i wouldnt do ..... on the other hand solving the problem is something i would go for

lineup · 14th January 2009, 08:18 PM

Quote:

Originally posted by vento
The amp is the Music Fidelity E10 and works fine other than this problem.
I had thought on the lines of capacitor discharge,
but this is not a short burst of sound,
it sound more like an aircraft crashing! (not joking),
and lasts about 5-6 seconds.

I is more serious than I first thought.
5-6 seconds ... hmmm
If you can provide more info, somebody may figure out what is the trouble.
At least we now know what amplifier: Music Fidelity E10

Nico Ras · 14th January 2009, 08:56 PM

Quote:

Originally posted by sakis

as about adding a relay in amp like that is something that i wouldnt do ..... on the other hand solving the problem is something i would go for

Hi Sakis,

You speak like a real technician. lets find the fault. Not lets put something to hide the fault so you dont know it is there even if it is getting worse.

Nico

Nico Ras · 14th January 2009, 08:59 PM

Quote:

Originally posted by lineup
This is quite normal.
And nothing to be very afraid of.
At power off the big electrolytic capacitors take some short time to dis-charge.

A way to avoid this would be to use an output relay.
This relay should immidiately disconnect speakers when OFF switch pressed.
This is probably how most commercial amplifiers do it.

Along with a delay to connect speakers at POWER ON.
To let everything get charged, settled and stable, before connect the speakers.
This will avoid any 'pop' sounds at power on.

Hi Line-up,

not the answer that I would expect from a respectable audio designer.

Nico

You sound like the snake in Jungle Book -"look into my eyes and trust me, nothing will happen"

mightydub · 14th January 2009, 11:05 PM

Quote:

Originally posted by Nico Ras

Hi Line-up,

not the answer that I would expect from a respectable audio designer.

Nico

You sound like the snake in Jungle Book -"look into my eyes and trust me, nothing will happen"

It depends on the specifics of the design, of course, but in my experience, lineup's answer is perfectly reasonable.

13th January 2009, 08:15 PM	#1
vento diyAudio Member Join Date: Oct 2008	Noisy Amp My amp makes a noise on power down (through the speakers). Anybody any ideas?

13th January 2009, 08:21 PM	#3
lineup diyAudio Member Join Date: Dec 2005 Location: the north	This is quite normal. And nothing to be very afraid of. At power off the big electrolytic capacitors take some short time to dis-charge. A way to avoid this would be to use an output relay. This relay should immidiately disconnect speakers when OFF switch pressed. This is probably how most commercial amplifiers do it. Along with a delay to connect speakers at POWER ON. To let everything get charged, settled and stable, before connect the speakers. This will avoid any 'pop' sounds at power on. __________________ lineup

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13th January 2009, 08:19 PM	#2
dave_gerecke diyAudio Member Join Date: Dec 2007 Location: Vermont	Hello Vento, more details would help a lot, kind of noise, make and model of amp. These will help others give you ideas as to whether it is a problem or not. Peace, Dave

14th January 2009, 10:27 AM	#4
vento diyAudio Member Join Date: Oct 2008	Hi, Thanks for your replies so far. The amp is the Music Fidelity E10 and works fine other than this problem. I had thought on the lines of capacitor discharge, but this is not a short burst of sound, it sound more like an aircraft crashing! (not joking), and lasts about 5-6 seconds.