PS reversed polarity! What did I damage in my ACA & B1?

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Bing, Bing, Bing!

The prize in this weeks goes to the man in the Canadian hat...
It appears that the power socket that I purchased for the laptop supply to plug into has some sort of voltage limiter thingy. If I jam the +ve wire from the board up the orifice and hold the other one on the outside of the jack and do not use the power jacket socket, then I see 19.5V on the supply rails.

I purchased the board components from Nelson's original article but had real problems finding a socket for the 7x5mm laptop power supply and this was one of the few I found. If anyone can guide me to a better part it would be much appreciated.
I will now go and see if I can make it smoke...
thanks
 
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Sometimes SMPS have much much lower ripple at 60Hz (no hum), they may have some 400kHz hash but that is easier to filter out.

Here is a crazy but true story - I reversed positive and negative once on an amp the result of a late night build sesson and groggy eyes not seeing the +/- silkscreen on the PCB spade plugs - I heard a heavy hum from the 400VA 24V trafo it was shakin', then the wires connecting the trafo to PSU (rectifier and caps) smoked, then glowed, then I figured it out and unplugged it (3 seconds tops). So dumb mistakes are (1) no fuses (2) working late at night. Mistake (1) now fixed as fuse permanently installed on mains to trafo as a minimum. But even though the wires were charred and the PSU diodes got smoked, nothing on the amp was damaged. It was like it just cross conducted through the output MOSFETs in a perfectly safe way. Pure luck I guess. I still work late, just make sure eyes are not groggy. :)

Anyhow, if you plug it in correctly, does the amp still work?
 
... had real problems finding a socket for the 7x5mm laptop power supply and this was one of the few I found. If anyone can guide me to a better part it would be much appreciated.

I don't know if you want to cut into the supply cable to fit a new connector 'combination', or just want a different jack.
I posed a question about the connectors for a DC power supply a while ago- got some interesting ideas, including some of the Neutrik ones which would be my choice, now.
http://www.diyaudio.com/forums/pass-labs/304355-dc-connector-amp-separate-power-supply.html#post5003660
 
Fixed

So it works fine. Nothing wrong with the semiconductors - purely down to the DC power jack socket. I cut the jack off the end of the laptop charger and hard wired it in. B1 buffer and both ACA boards running great. Bias voltage set to 10V no problem.

Plays great.

Next up a Poddwatt, headphone amp and then I'll think about a full fat Nelson Pass Amp.

Many thanks
 

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