Something seems fishy. 60Hz is 16mS. How can it thump in less time than a powerline cycle? Even a 1/2 cycle is 8mS, how is the regulator not holding 8 mS?
I agree with you MikeAtx. Getting rid of thump is best dealt with by disconnection of the speaker from the amplifier output. Attempting to do it earlier in the signal chain is difficult at best. Personally, I prefer not to use mechanical relays in this process.
Reality stinks. I wish I had a storage scope to see what was actually happening. I am using a SMPS followed by a 4 Ohm resistor and a 4700uF cap feeding the two boards, roughly 200mA. It drops like a rock. My attempt at a relay mute was to tap with a diode before the caps, into a 555 timer controlled relay. I added 100 Ohm resisters in series with the outputs after the blocking cap and then was shunting that to ground. Not fast enough.
I agree, I prefer not to have a relay in the signal path.
What is the minimum supply voltage the MOSFET boards will function with? I might try one on the sub plate first as I don't mind chopping into it. My main amp is brand new. Once a year old, I might consider replacing it's internal relay with this concept.
I agree, I prefer not to have a relay in the signal path.
What is the minimum supply voltage the MOSFET boards will function with? I might try one on the sub plate first as I don't mind chopping into it. My main amp is brand new. Once a year old, I might consider replacing it's internal relay with this concept.
The MOSFET SSR boards that jhofland designed that I use have a voltage regulator to generate 15v so it needs about +3v above that so 18vdc will give a reliable voltage needed for the comparator circuitry to work reliably. The regulator is special in that it can handle up to 150v input. The low capacitance PSU fed from the main PSU secondary works very well to shut if off instantly.
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