Buying used amp. What can you actually look for?

[JakeW]

The physical damage is pretty easy, but how to determine if an amp has been taken care of electrically?? I don’t have a dyno, just basic dmm. Looking at a dc audio 5k. Found 2 local for $600 & $800. Brand new they’re $1500. Just looking for some serious advice here, the one is on a at least 2nd owner I know of. Thanks in advance

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[Popwarhomie 5,000+ posts]

Just a gamble with used amps really. I bought a pawn shop AQ2200 that was beat to **** but I ran it for a long time no problem at .5 ohm

 

[metalheadjoe 10+ year member]

Physical condition is a great indication of how something has been treated. Other than that, you have to use your instincts.

 

[JakeW]

Damn. Unfortunately I don’t have enough experience with amplifiers lol used especially! Anything come to mind as far as any sort of possible bench test in colorado?

Physical condition is a great indication of how something has been treated. Other than that, you have to use your instincts.

 

[JakeW]

You lucked out there! I’ve heard theee 5k are beasts so maybe there’s no worry. Imma touch base with dc tomorrow

Just a gamble with used amps really. I bought a pawn shop AQ2200 that was beat to **** but I ran it for a long time no problem at .5 ohm

 

[Bobbytwonames 5,000+ posts]

Damn. Unfortunately I don’t have enough experience with amplifiers lol used especially! Anything come to mind as far as any sort of possible bench test in colorado?

Meet the seller at a Car Audio shop that can bench test it for you. They might charge you $10-$20 to do it. Maybe the seller will split that cost with you if you decide to buy it.

 

[JakeW]

I’m gonna look for shops that’ll do that in the Denver area! Thanks

Meet the seller at a Car Audio shop that can bench test it for you. They might charge you $10-$20 to do it. Maybe the seller will split that cost with you if you decide to buy it.

 

[JakeW]

I’m gonna look for shops that’ll do that in the Denver area! Thanks

I feel like I could easily bench test it to my subs, pretty much just an install out of the vehicle

 

[Bobbytwonames 5,000+ posts]

I feel like I could easily bench test it to my subs, pretty much just an install out of the vehicle

You can bench test amps with phones as well.

 

[Deiimos]

I agree it is a gamble. An amp can be working fine then blow. One person might get away with running below rated impedance, the next person fry it quick from different impedance rise. I’ve also gotten amps that looked brand new with original box that were blown (I knew this when buying as I bought them like that cheap to repair, but they were like brand new, not a scratch), have also seen amps scratched, corroded and or rusted to hell and they played great for a long time. There is really nothing to say with certainty if an amp is going to give problems, not even a dyno test. By the time internal components look bad, it’s usually dead by then. About the best you can do is test it at its minimum impedance to make sure it works before buying, if it works it is “likely” okay. Maybe ask what impedance they were running it at. Below rated impedance can often be bad for amps even if they seem to function there, some hold up better than others.

 

[Bobbytwonames 5,000+ posts]

I agree it is a gamble. An amp can be working fine then blow. One person might get away with running below rated impedance, the next person fry it quick from different impedance rise. I’ve also gotten amps that looked brand new with original box that were blown (I knew this when buying as I bought them like that cheap to repair, but they were like brand new, not a scratch), have also seen amps scratched, corroded and or rusted to hell and they played great for a long time. There is really nothing to say with certainty if an amp is going to give problems, not even a dyno test. By the time internal components look bad, it’s usually dead by then. About the best you can do is test it at its minimum impedance to make sure it works before buying, if it works it is “likely” okay. Maybe ask what impedance they were running it at. Below rated impedance can often be bad for amps even if they seem to function there, some hold up better than others.

All good advice assuming that the owner won't lie to you. It is a crap shoot though. I would say the best way to buy a used amp is if it is still hooked up.

 

[Bobbytwonames 5,000+ posts]

My number one question would be why are you selling it? #2 would be can we bench test it at a Car Audio shop? Maybe I'm an optimist but I have sold amps before and I wouldn't be able to live with myself if I knew the amp was fukked up when I sold it. I've also bought used amps and wanted proof that they weren't DOA. Do your due diligence and go with your gut instinct after that. That's pretty much the nature of the game.

 

[JakeW]

Well said guys. Good advice! This one is being sold due to upgrade, was powering 2 15” @1, now got a salt 8 for 3 subs. But this was also bought from an guy used! That’s where I’m at with the bench test, it’s awesome it’ll turn on but once cash hits hand it’s my problem if it goes down lol

 

[hispls 5,000+ posts]

The only thing to really worry about is if it has been repaired by someone incompetent recently. You wouldn't know without disassembling components from the board though. New or professionally repaired these big Korean amps are still not 100% reliable so you're rolling the dice doing anything outside of buying brand new with a warranty.

For practical purposes a less than 5 year old Korean amp that powers up and functions for half an hour is going to be just as reliable as one right off the assembly line.

 

[Popwarhomie 5,000+ posts]

The only thing to really worry about is if it has been repaired by someone incompetent recently.

I agree. I pass on amps that have been repaired.