MB-Quart-ONX4.125 - 13 months and it's DEAD

[Jean]

Just an FYI to those who are considering these "MB Quart" ONYX amplifiers.

This is my FIRST amplifier that failed in such short time, the last amplifier I've used lasted me through 3 cars and over 7 years? (Good old made in USA Phoenix Gold TI series).

http://www.sonicelectronix.com/item_...-ONX4.125.html

The amp above has been used in a very simple system-
Alpine CDA-105 headunit
Image Dynamics Components
Polk Audio DB12 svc 4ohm subwoofer in Luke's custom box.

Amp started turning off about a month ago, I didn't think much of it and thought maybe it got too hot and shut off...It would come back on after a few minutes and everything would be fine.

Now it won't even stay on for more than a couple of minutes at LOW volumes.

I've contacted Sonic Electronix to see if they'll go an extra mile to cover it, I told them I'll make sure to share my good experience on many forums and audio lists :D

[Gregs///M]

I would first verify power during non operation before assuming your amp is toast. Particularly your ground cable. Verify both ends of the cable are indeed clean and corrosion free. Be sure the chassis end is touching bare metal.

You should see at least 12 volts on the main power cable and 12 volts on the remote turn on cable while the system is powered.

It is very rare to find a 4 channel amp overheat unless it is bridged to very low impedance using sub woofers.

Does your amp power indicator shut off or just the audio?

[Jean]

All connections are good, I've already checked everything before making this post and contacting the seller.

The rear two channels are bridged into a single 4ohm sub (svc). I know a thing or two about electronics and audio (build many home audio hifi amps/preamps/crossovers etc), just not happy that it failed so quickly.

I guess you can't expect much from these made in china amps.

Do you repair amps? I may open it up if they don't offer to replace it.

[Gregs///M]

I can repair it, if I can source out all the replacement parts. Usually power transistors go.

Hopefully they replace the whole amp.

GL

[E30_Pare]

:( I was about to get this amp. Heard good things about mb quart & seemed to be of some quality

[Jean]

^ It's not exactly an MB Quart amp of the past, it's a made in china Maxxsonics?

[Jean]

They won't cover it under warranty but offered me another new one at lower cost + 3year warranty and s/h included. I may go for it after I open this one up first.

[E30_Pare]

So what would be a good alternative 4 channel for the price?

[Jean]

You can't beat this one for the price alone, just pay for the 3 year warranty.

[dwvw]

All connections are good, I've already checked everything before making this post and contacting the seller.

The rear two channels are bridged into a single 4ohm sub (svc). I know a thing or two about electronics and audio (build many home audio hifi amps/preamps/crossovers etc), just not happy that it failed so quickly.

I guess you can't expect much from these made in china amps.

Do you repair amps? I may open it up if they don't offer to replace it.

Did you use a multimeter? Or just visually inspect it?

[Jean]

Yes, there is voltage all the way up to the amplifier power terminals it does not go away when the amp stops making any sound.

[greentalks43]

I have had the best of luck with used Kenwood KAC-729 2 channel and Kenwood KAC-749/849 4 channel amplifiers for my installs. I cannot recommend these amplifiers enough, especially for how little you can get them used on eBay.

[5Toes]

Get a precision power. Almost the same price

Luke really likes them. He was recommending their 5 channel all the time a couple years ago

[Jean]

This one looks similar in specs and power, it may be the same thing internally lol - http://www.sonicelectronix.com/item_...r-BK800.4.html

[5Toes]

http://www.ebay.com/itm/PRECISION-POWER-PPI-S760-4-760W-RMS-4-2-CHANNEL-CAR-AMP-STEREO-SPEAKER-AMPLIFIER-/320946913871?pt=Car_Amplifiers&hash=item4ab9ed424f&_uhb=1

nice amps for what they are