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mw
Guest
What causes speaker pop in audio amplifiers? The "pop" occurs when the
amp is first turned on. It also can occur as the amp is turned off.
What is a good strategy to prevent it, especially for a MOSFET amplifier
design?
I think I read somewhere that it is caused when the speaker is driven
but voltages haven't yet attained their stable points. If that is true
is there a good way to clamp intermediate stages for a while till all
the voltages are stable? Like with a FET or an analog switch?
My review of amplifier designs and my own use of available products I
see that:
"Build it yourself" amp articles on the Internet usually don't even
mention that speaker pop exists. I assume this is because 1) they are
experimental and the main goal is just getting them to work at all...
and 2) It's just amusing reading material and no one usually builds
them, so who cares? ;-)
My guess is that tube amplifiers don't suffer from this because at first
turn-on the tubes aren't heated enough to drive the speaker hard enough.
Maybe they do pop if you warm them up a long time then cycle power.
I don't have one to experiment with. Looking at guitar schematics I do
not see any special circuitry to address speaker pop. Maybe the
guitarists always turn the amp gain all the way to zero every time, or
maybe there is a standby switch on some tube amps.
Both my home audio tuner amps (an Onkyo and a Sony) have some sort of
elaborate speaker loading detection circuit involving a relay. I can
hear it clicking, and there is an annoying delay. I don't recall
anything like this in my old Kenwood tuner amp.
I think most simple amps, like a solid state keyboard amp I have, just
hit the speaker with a big pop at start-up, a smaller pop at turn off,
and the owner just learns to ignore it. It probably is tough on the
speaker, but it is a "cheap" work-around... do nothing.
amp is first turned on. It also can occur as the amp is turned off.
What is a good strategy to prevent it, especially for a MOSFET amplifier
design?
I think I read somewhere that it is caused when the speaker is driven
but voltages haven't yet attained their stable points. If that is true
is there a good way to clamp intermediate stages for a while till all
the voltages are stable? Like with a FET or an analog switch?
My review of amplifier designs and my own use of available products I
see that:
"Build it yourself" amp articles on the Internet usually don't even
mention that speaker pop exists. I assume this is because 1) they are
experimental and the main goal is just getting them to work at all...
and 2) It's just amusing reading material and no one usually builds
them, so who cares? ;-)
My guess is that tube amplifiers don't suffer from this because at first
turn-on the tubes aren't heated enough to drive the speaker hard enough.
Maybe they do pop if you warm them up a long time then cycle power.
I don't have one to experiment with. Looking at guitar schematics I do
not see any special circuitry to address speaker pop. Maybe the
guitarists always turn the amp gain all the way to zero every time, or
maybe there is a standby switch on some tube amps.
Both my home audio tuner amps (an Onkyo and a Sony) have some sort of
elaborate speaker loading detection circuit involving a relay. I can
hear it clicking, and there is an annoying delay. I don't recall
anything like this in my old Kenwood tuner amp.
I think most simple amps, like a solid state keyboard amp I have, just
hit the speaker with a big pop at start-up, a smaller pop at turn off,
and the owner just learns to ignore it. It probably is tough on the
speaker, but it is a "cheap" work-around... do nothing.