Did I kill my headphone amp?

[Sintek]

Amp: Maverick Audio TubeMagic A1.

Earlier today I replaced my amp's faulty potentiometer. As a novice, I was worried something may have gone wrong and the amp wouldn't function, but thankfully it worked, and sounded better with a fully functional gain pot. So with renewed confidence I decided to replace a couple capacitors. After unplugging it, I made sure to cycle the power button a few times and manually short the caps so they were fully drained before beginning, yet during the solder removal I experienced some scarily loud sparks on a completely different part of the board, and again while putting the board back on the standoffs.

Now that I have the new caps in place and everything back together I'm afraid to turn it on. I don't see any blackened components though I know that makes little difference. Is there any chance it could have survived those shorts?

 

[TLS Guy]

Amp: Maverick Audio TubeMagic A1.

Earlier today I replaced my amp's faulty potentiometer. As a novice, I was worried something may have gone wrong and the amp wouldn't function, but thankfully it worked, and sounded better with a fully functional gain pot. So with renewed confidence I decided to replace a couple capacitors. After unplugging it, I made sure to cycle the power button a few times and manually short the caps so they were fully drained before beginning, yet during the solder removal I experienced some scarily loud sparks on a completely different part of the board, and again while putting the board back on the standoffs.

Now that I have the new caps in place and everything back together I'm afraid to turn it on. I don't see any blackened components though I know that makes little difference. Is there any chance it could have survived those shorts?

Well that amp is suitably named, "Maverick" it is. You followed sound procedure. So obviously this is a poorly designed piece of junk.

However that unit obviously has some high voltage caps that do not have bleeder resistors, which is bad lazy design and a safety defect. In a properly and safely designed unit all caps should drain down after a few minutes from installed bleeder resistors.

Now as to whether the unit is ruined, works or safe I can't say. I don't know the circuit and I don't know the location of the caps that discharged during service. I think however all this violent sparking is not a good omen.

However the proper procedure after an event like this is to bring the unit up slowly with a variable voltage autotransformer known as a Variac and observe closely with instruments as the voltage is slowly increased.

As a matter of interest why were you replacing the caps? I hope you were not fixing what wasn't broken. Since the unit was working I fear this is the case, and I suspect the biggest lesson for you from this event.

 

[Sintek]

Thank you for the detailed reply.

I know it could have been avoided - I've been reciting to myself "live and don't learn" because this isn't the first time I've destroyed something by trying to fix what isn't broken. If only I'd just been happy with the potentiometer that actually did fix something.

 

[Sintek]

I may have found the culprit: a resistor with a hairline crack. Could this have caused the spark, or did the spark kill the resistor? I'm holding out hope that replacing it will result in a working amp. I just wish Radio Shack stores still existed so I didn't need to have one tiny component shipped to me.

 

[slipperybidness]

I may have found the culprit: a resistor with a hairline crack. Could this have caused the spark, or did the spark kill the resistor? I'm holding out hope that replacing it will result in a working amp. I just wish Radio Shack stores still existed so I didn't need to have one tiny component shipped to me.

If you happen to have a Fry's nearby, they may have what you need in stock.

 

[TLS Guy]

I may have found the culprit: a resistor with a hairline crack. Could this have caused the spark, or did the spark kill the resistor? I'm holding out hope that replacing it will result in a working amp. I just wish Radio Shack stores still existed so I didn't need to have one tiny component shipped to me.

No, the discharge damaged the resistor. Don't assume any possible damage ends there. Most failed components look OK.

Thinking about this unit, it is not expensive enough to warrant a trip to a service department.

When you replace the resistor put it back together. If it does not have a three pin mains plug, soundly ground the case. Then fire it up. If it smokes or does not work take it to the recycling center, and get something else.

Last piece of advice is that it is total superstition that tubes make it sound better than a unit without tubes.

 

[Sintek]

Last piece of advice is that it is total superstition that tubes make it sound better than a unit without tubes.

I understand that, and I know it's a low-end amp unworthy of lengthy repairs. I picked it up cheap so it's no big loss. If anything, it makes a nice practice project for soldering and modding. Thankfully I have a Schiit Magni 2 Uber arriving today, the case of which I vow never to open.