Noisy Amp

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
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,
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.
 
line up ......

lineup said:
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
 
lineup said:
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
 
vento said:
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
 
lineup said:
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.:confused:

Nico

You sound like the snake in Jungle Book -"look into my eyes and trust me, nothing will happen" :devily:
 
lineup said:
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 use a microcontroller and a relay to do this.
The micro gives a 3 second delay to the relay on power up.
It also looks for looks for DC output (fault state) and disconnects the speakers if a fault state is found.
 
lineup said:


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

Hi Line-up, I was joking with my comment of course.
:)

I came across a problem many years ago on a guitar amp which may or may not be similar, but what happened was that a little while after turning power off a whistling sound came from the speaker and died down as the capacitors discharged.

The problem lay in one rail discharging quicker than the other and the amplifier became unstable as it got to some threshold voltage.

The reason for the unequal discharge was that all pilot lights were connected only to one rail of the power supply.

Regards

Nico
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.