Axiom Home Page Forums General Discussion Advice from Axiom Owners Power Amplifier Troubleshooting

I was just sharing this Rotel stuff vs. ADA with my eng homies. How times have changed. The ADA is so much simpler, more elegant in its design and execution. BTW, I've tried to kill my 1000 by abusing its outputs and have not been able to do so.

Boom!

Off to the store for fuses

Saaaweeet! Did you check all the fuses on that side? Which one was blown?

Make sure you get the exact same fuse. That one is a slow blow which is the way most engineers like it.

Nice Job ...

Buy a few off those fuses in case something else is wrong which re-blows the fuse ...
Or if you accidentally short your speaker leads again in the future ... (that protection IC protects the speaker ... the fuses are suppose to protect the amp ...)

When you get it working tape the extras to the inside cover so you have them when needed.

Actually I thought the opposite ... this is the simpler amp in that all the components are discrete (except for the op-amp and the speaker protection IC). You can really see how the thing works. Its very testable making it an easy piece to fix.

I have not looked at the ADA but I'm sure all the complexities are in the chips. Simpler in number of components more complex in understanding how it works. Most engineers just following the reference design and read up on each chip to attempt to understand what pin does what. Often the chip internals are a complete mystery, maybe you get a block diagram, although sometimes they give you the internal (simplified?) circuit (which usually is not that simple). Just MHO ...

It was just the one fuse.

I can't thank you all enough!


I now will be doing the tedious task of hooking it all up! Stay tuned!

You worked up the courage and did all the work, dude. Congrats. I'm glad you managed to salvage that hunk. Let's hope she doesn't blow!

thanks. *fingers crossed*

Rich, "simpler" was an over-simplification on my part. Andrew worked on that thing for 2 years. I'm sure others were helping him with it. And how many years before that were others working on it like Tom Cumberland? At least 8 or 10. So there's lots of history with it and one of the reasons I really dig Ian is because he had the intestinal fortitude and vision to know what is the right thing to do.

I'm not sure the ADAs use a chip other than for protection; I have not looked closely at the amp channel boards. I don't know where technology is today with regard to class D ICs. I know when I was involved with it in 2002, we had to build high current and high voltage channels with class D amps from scratch and it was a total nightmare because we couldn't achieve the required stability and EMC.

When I look at the guts of the ADA, it's simple in that you can readily see where everything is and it's easy to access. It should be straight-forward to replace the rectifier/filter board for example when it comes time to re-cap because it's readily accessible and has what looks like four screws. Ditto with the amp channel boards.