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Ready-to-Run (RTR) SSR DC Speaker Protection and Delay GB

Founder of XSA-Labs
Joined 2012
Paid Member
No, 2 wires are +ve and 2 are GND. The top 2 are GND and bottom 2 are +ve from amp on left and to the speaker on right side. Just look at the traces. They are paralleled for more current.

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Hi Tcpip,
Thanks for the note to let us know it all got there in good shape. Thanks for your order - 6 is a lot to send to Bombay! I think the packaging worked out well then.
Let us know how they work out!
Cheers,
X
I most certainly will (let you know). I'm currently slightly worried about electrostatic damage to the MOSFETs in storage, since I'll take a few months to put together the amps which will use these modules.
 
Founder of XSA-Labs
Joined 2012
Paid Member
I just finished installing a set of these SSR's on my new Alpha Nirvana amp. Using only a single spade connector for IN and OUT and a Molex KK with amp PSU (provided through matching Molex KK header built into the Anlpha Nirvana PCB for the SSR). Sot it was all very easy and quick work to have SSR speaker protection now in place. No more turn on thump!

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See the 2pin Molex KK connector at the bottom right of the PCB?
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Hi I have some interest in these,I use Valeman boards at the moment which are OK but have relays in the speaker lines.The amps boards I use have separate earths for the front and back ends and join together with the speaker earth at the star point on the power supply.The Valeman is also earthed there can your board be connected in the same way
,also what is the resistance of the 2 FETs in the positive line?
 
gwmorgan,
The FETs used are Nexperia BUK9Y15. The spec value RDSon is 12.1milliohms typical, 15 milliohms max so the incremental resistance through the FETs is less than 30 milliohms. Sensing for output DC offset is with respect to the amp out low side which would be the same as what you refer to as speaker earth. It should work just fine with your described arrangement.
 
meanie,
The answer to your question depends on a number of uncontrolled variables. If there is an amplifier offset on power down and there is still power to the SSR circuit tripping will occur in a few milliseconds.There are a number of other scenarios during power down where it is less predictable.
 
gwmorgan,
The FETs used are Nexperia BUK9Y15. The spec value RDSon is 12.1milliohms typical, 15 milliohms max so the incremental resistance through the FETs is less than 30 milliohms. Sensing for output DC offset is with respect to the amp out low side which would be the same as what you refer to as speaker earth. It should work just fine with your described arrangement.

Ok thanks that's clear.
 
I bought 2 of the last 10 units in the store. I don't wants damage my expensive field coil full range. I ordered years ago. Is hand made craftsman in Germany, I am afraid my chip amp is proud to pass DC, and has already damaged an speaker voice coil.
Also I have a project, a 6w. ACA amp. (Class A solid state), I don' t know If also this will require protection.
 

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