I blew my amp9.

[Therum]

Hello Everyone,

As the title states I blew my amp9. Its somewhat odd since it was working fine last night. I go to turn it on today and nothing. I unplug the power supply (20v Laptop "Brick") and plug it back in and I get a .75 - 1 sec pulse. Then I get nothing. Or so I thought. Long story short is that the amp is now showing 19v dc on the outputs. The only thing I did last night that may have been a no no was that when I unplugged my mp3 player the mini jack touched one of my tools that was on a wooden bench and I heard feedback. I didnt think anything of it since my next move was to flip the "muting" switch and then turn the amp itself off. The PS is connected to a switched outlet. So maybe thats what essentially killed the taa4100a. I checked all of the diodes and transistors on the board and they are ok. I see no switching pattern on any of the outputs, inductors, output pins on the 4100a. So I think its dead. So here is my question. Is there something I can insert between the audio source and input pins to prevent this from happening again.? your input is greatly appreciated. and yes. I can already hear the comment "Dumb A$$$"

[SAC]

Have you posted on the 41Hz forum? I did so recently when I killed my amp9 basic and got prompt and effective support.

[nigelwright7557]

You could put diodes to the input rails to clip any spikes.

[SAC]

Originally Posted by nigelwright7557

You could put diodes to the input rails to clip any spikes.

I'm not an expert, far from it, but I will comment on my particular experience since it may be relevant. I bought an amp9basic which does not come with the input protection diodes installed, but are included if the user wishes to install them. I opted against it, but when I later added a transformer and consequently got higher input levels, my amp fried during the loud passage of a movie. It was a disaster waiting to happen. I wonder if you have those input protection diodes installed Therum?

I do not know if this relates to what you describe Therum but my thread can be found here;
Help! Amp9b assembled died during loud passage..

[nigelwright7557]

I have found the irs2092 also gets a bit upset with being overdriven.
It can cause it to reset but I havent blown up any chips yet.
I put in back to back zeners on the input to limit input voltage.

[Therum]

Thanks guys. I did see that thread. But my amp9 is a 1.01. I noticed that there are 8 empty places for diodes but none are connected to the audio traces. The thing that baffles me is that how can shorting the inputs cause such damage. Thats where my confusion comes from. I have played it near the maximum output of my mp3 player (Microsoft Zune) for hours at a time without issue. But the only thing different last night was that it grounded on one of my tools mere seconds before I shut it down. I will try the 41hz forum for additional unput. I have already ordered a replacement chip. I will research further to prevent this from happening again.

Thanks!!