A worse feeling than burning out your amp?


Last night I was planning to get back into making digital music and began setting up my laptop with the necessary software. I had my audio cable (1/8" connector) plugged into my Macintosh, which was playing mp3s. The laptop was ready to go, so I unplugged the cable from the Mac without turning the amp off, which I've done dozens and dozens of times before; BIG mistake. I heard a very loud buzzing sound that lasted about a quarter of a second, followed by a loud pop. I went over to the amp and could smell electronics burning. I turned the amp off and back on, after which I noticed that sound was only coming out of the left channel and it was very broken and full of static. Also, it doesn't matter which input is selected, it plays all sound coming from all inputs now. This integrated NAD C 340 amp is no longer good as a preamp either. What a horrible feeling, but it could have been much worse (my speakers could have blown out!).

Has anyone ever done something similar to their amp and attempted to fix it? I'm at least going to open it up and have a look before I trash the thing. The only bad part about all of this is having to wait several months before I can afford to replace this unit. For now, it's back to the old mass market Kenwood receiver....
jwglista

Showing 4 responses by jwglista

What does it mean to "blow a channel?" Does this mean a blown capacitor, resistor, or the entire electrical path?
Yes well it's good to know that I'm not the only that has made such a foolish mistake. I never thought that pulling a cable out like that could fry something. I do think that it's the preamp that is toasted, so I'm going to open it up and look for any burnt components. If it's just a resistor, I may be able to apply my mediocre soldering skills and replace it. I only paid $90 for this amp on EBay, which is one of the reasons I said it could have been much worse. Either way, it's not worth my money to bring this into the shop. I was saving up for a new DAC, but my funds will have to be diverted towards a new amp (unfortunate, because I really need a better CD player or DAC).
Well I took the amp apart and noticed an area of smoke build up on the top of the cover right above a big capacitor (there are 2 of these in the amp, I'm assuming one is for each channel). I don't know much about electronics so I don't know if it would be worth my time to try and fix this. I also don't know if a burned out capacitor would explain why the amp plays all sound from all inputs at the same time, regardless of which input is selected. That sounds like something in the preamp got fried too....
Yioryos, yes it is a good excuse to upgrade my amp. The thing is, I was going to upgrade my DAC which was a bit more necessary, but now I have no choice but to buy another amp (I'm using a Kenwood receiver right now).