I'm building an Arduino controller for a Class D amplifier. Basically I'm controlling power on/off as well as volume to make a nicer speaker set up to wake up to. The details aren't really relevant.
The problem I'm having is that I'm switching power to the amplifier via a solid state relay. Power on works fine as the amplifier has a startup delay circuit so it waits to warm up before driving the speakers and avoids the startup pop. But on shut down, my relay interrupts ground I believe and I get a pretty nice pop.
Is there a simple solution to the shutdown side of this problem?
The problem I'm having is that I'm switching power to the amplifier via a solid state relay. Power on works fine as the amplifier has a startup delay circuit so it waits to warm up before driving the speakers and avoids the startup pop. But on shut down, my relay interrupts ground I believe and I get a pretty nice pop.
Is there a simple solution to the shutdown side of this problem?
If the amplifier 'slow start' is simply some inbuilt electronic function within the amp then it may not be enough. The electronic mute is not a physical interruption and ideally a speaker slow start should be a relay that also disconnects pretty instantly when the power is removed.
A SSR for the power switching rules out arcing and RFI as a cause.
Ultimately there are many reasons... reasons that may be specific to your design. Maybe the DC rail/s collapse to slowly (or to quickly) for the amp to mute correctly, or maybe its just 'normal' for that amp. Either way a quick speaker disconnect is the best fix, and by quick I mean within a few milliseconds of the mains disappearing.
A SSR for the power switching rules out arcing and RFI as a cause.
Ultimately there are many reasons... reasons that may be specific to your design. Maybe the DC rail/s collapse to slowly (or to quickly) for the amp to mute correctly, or maybe its just 'normal' for that amp. Either way a quick speaker disconnect is the best fix, and by quick I mean within a few milliseconds of the mains disappearing.
A simple board like this will do that:
Dual channel UPC1237 Speaker Bescherming Boord Kit Boot Vertraging DC Bescherming DIY in Dual channel UPC1237 Speaker Bescherming Boord Kit Boot Vertraging DC Bescherming DIY van Instrument Onderdelen & Accessoires op AliExpress.com | Alibaba Groep
Preferably with a seperate powersupply, so it acts immediately.
Regards, Jan.
On my amp it happens because the power supply slowly ramps down the power and the undervoltage protection kicks in. No input or anything, as long as the speakers are connected it pops. Putting my amp in reset mode (since it doesn't have a mute) cures the problem for start up and shutdown pops.
Not quite sure what you are describing with photorelay but the actual contacts that switch the speaker must be either mechanical or be a dedicated and specially designed solid state one (which normally is optically controlled).
A normal solid state relay used for mains switching (which uses a Triac as the control element) isn't suitable for speaker switching.
A normal solid state relay used for mains switching (which uses a Triac as the control element) isn't suitable for speaker switching.
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