Big problems. HELP

[Virumflame]

I have just managed to destroy my two Ta2020 Lepai.
I can't find out why!
My setup is shown in the pictures! The amplifier just started smoking when I turned it on...

 

[Virumflame]

hook to a standard 12V car battery

 

[johnr66]

Are you sure the red wire on the power cord connects to the inside of the barrel on the jack? Some of these are reversed (+ on the outside). Check polarity with meter. Bet it is reversed.

 

[Virumflame]

in the third photo in the upper right corner of the amplifier there is a little sign. That means that the outside of the power wire is minus and the inside is plus right??

 

[Virumflame]

Sorry it is the 4th picture

 

[kevinkr]

Check whether the red wire in your cable actually goes to the center conductor of that plug.

You probably know this already but you should always have a fuse in the line to the battery, not that this would have saved your amps - it might prevent some other mischief however. Your set up is not safe.

It is also a really a good idea to check the polarity with a meter before plugging in.. (Check twice, plug once.)

 

[Virumflame]

I had a fuse on 15 a on the plus wire. It is still intact... To many A perhaps or what???

I measured how many volts my battery had. When I measured with the minus wire to minus and the plus wire to plus nothing happend. Then when I switched it so plus were on minus and minus on plus. This does not have anything to do with my amps now being broke right???

 

[jordheis]

Show us the connections at the speaker. Shorted?

What test are you performing?

Also - your big red cable clamp is mighty close to the amp's case. I suggest better isolation of your power source.

 

[djmeverett]

Seriously
Yeah car battery with 60A potential with a 15A fuse?!!
The whole thing would catch on fire before that 15A popped.
How come you don't use a 12VDC/2A wall wart?
Just asking for smoke there....LOL

 

[Virumflame]

I am new to this world, and this is apparently a rookie mistake. What should I change in the setup so this won't happen again??? What size fuse? other things?

 

[kevinkr]

As I suggested previously you needed to check that the polarity on the end of the plug was correct before inserting it. I suspect it is reversed despite your best efforts. When one device smokes do not connect the other without first understanding what went wrong.

Fuse should have been much smaller, 2 - 3A to start..

Unlikely to be reparable unless there was a shunt diode that went up in flames and even then...

Best to start anew. Use the power supply that comes with it.

 

[Tekko]

These amps are pure trash anyways, i tried one and it was totally unlistenable, it have since been reduced to a passive volume control.

 

[djmeverett]

I think I would start out using a proper PSU.

Amazon.com: Lepai Amplifier 12V 2A Power Supply by Parts Express: Electronics

There are other places to get that power supply...in fact Parts Express sells that amp with the power supply!!

Amazon.com: Lepai Tripath Class-T Hi-Fi Audio Mini Amplifier with Power Supply: Electronics

Is there a reason why you were using a car battery and jumper cables?
Did you actually see smoke come out of the amp?
Did you smoke two amps???

 

[djmeverett]

These amps are pure trash anyways, i tried one and it was totally unlistenable, it have since been reduced to a passive volume control.

I'm sure for $20-30 it's not the greatest amp in the world but for that price it is what it is....a budget 20W amp!
I'm sure it will drive a couple of small 8 ohm bookshelf speakers in your bedroom and be a step up from a pair of PC speakers.

IF you think it will drive some big ole 15" woofers well then you're just kidding yourself!

 

[Bone]

The size of the speakers is immaterial. Its an urban myth that small amps cannot drive large speakers. Many small amps sound great through large speakers. You should hear a 1/2 watt Ruby through a 12". What is important is the speaker sensitivity. The higher the better.

 

[Tekko]

I'm sure for $20-30 it's not the greatest amp in the world but for that price it is what it is....a budget 20W amp!
I'm sure it will drive a couple of small 8 ohm bookshelf speakers in your bedroom and be a step up from a pair of PC speakers.

IF you think it will drive some big ole 15" woofers well then you're just kidding yourself!

I meant the sound quality, i couldent stand it at anuy volume level for more than a few seconds before i had to turn it off!

These class d amps are a total 100% waste of money.

 

[djmeverett]

The size of the speakers is immaterial. Its an urban myth that small amps cannot drive large speakers. Many small amps sound great through large speakers. You should hear a 1/2 watt Ruby through a 12". What is important is the speaker sensitivity. The higher the better.

Agreed, any size speaker can be driven....to a point.
But are we talking about a guitar amp or a bookshelf stereo chip amp here and for what use?
So everything needs to be understood about what the OP is trying to do...
For $30 who cares though it will make sound if you hook it up right...which apparently the OP hasn't accomplished yet...

 

[djmeverett]

I meant the sound quality, i couldent stand it at anuy volume level for more than a few seconds before i had to turn it off!

These class d amps are a total 100% waste of money.

So what do you recommend as a better alternative?
What type of speakers and source did you have hooked up to this one?

 

[Tekko]

So what do you recommend as a better alternative?
What type of speakers and source did you have hooked up to this one?

My recommendeation is: TDA7293, LM3875 and LM3886.

I used the same speakers on the lepai amp as on all my other amps that on even 5 watts of class A is deafeningly loud whilst still sounding very very good.

 

[djmeverett]

No disrespect Tekko, but those are the just the chips....I was thinking more along the lines of a $30 alternative "built" with PSU ready to go...
I know this is DIY Audio and no argument there are better alternatives DIY but the OP apparently is looking for something he can buy OTS and hook speakers and a source to...