XS 6600...you guessed it having troubles

[jaydubya2003]

So I did some searching, found a few threads talking about the current problem I am having. But I wanted to get it out there to try and get some more input. A couple threads seem to say mosfet supply...but what is your input?

I have a PG XS6600 that will blow two of the four fuses on the amplifier. Now I ran this amp for about a year in a different vehicle. It was running 4 speakers at 4 ohms, subs bridged down to 4 ohms. It ran great had no trouble. Pulled it out of that vehicle (a 1977 Scout II) and put it into my 92 Wrangler. Now in doing that I had to change to a different sub because of space issues which was running at 2 ohms (which I checked to make sure the amp was stable at 2 ohms bridged and it was). Now it ran great and then after running it pretty loud for about an hour or so driving in the freeway (with the top off of course...lol) it shut off, and I figured it got to hot and "protected" which turned out to be true because after letting it chill for a while it came back on. So I turned things down a notch and ran it like that for a while until it shut off again but this time it didn't come back on. Pulled it out pulled it apart and...nothing...not a single thing is dark/bubbly/melted/smells/or looks out of place. The only thing I noticed was that there was a kind of white paste that had oozed down the inside of the amp from the top down.


What are your thoughts guys, I would love to fix this thing and keep it around. I mean I have another amp I swapped in but I would love to save this thing from the junk pile...

[ttocs]

that amp is old enough that is is probably due to have the caps replaced in it. pull the amp out and take some pics of the circuit board for us and we can help to see if there is anything visably wrong with it.

[Bfowler]

where did you read/hear it was 2ohms bridged stable...

the xs4300 section....maybe, but the sub/xs2300 section is NOT 2ohms stable


did you look under the FET heat sinks?

[jaydubya2003]

Will do, should have pictures up tonight.

[ttocs]

http://www.onlinecarstereo.com/CarAudio ... S6600.aspx

it is 2 ohm stable for the mids and highs but not rated for the sub at 2 ohms mono, 2 ohms stereo.........

[jaydubya2003]

where did you read/hear it was 2ohms bridged stable...

the xs4300 section....maybe, but the sub/xs2300 section is NOT 2ohms stable


did you look under the FET heat sinks?

When I received the amp it had the manual, in there it shows the power rating for the sub channel bridged. Bridged it is 300 watts...no matter 4 ohm or 2 ohm...I remember because I thought "well damn that sucks I won't get any more power...but no biggy I'll just run it at 4 ohms and lessen the load" now that was in the first rig where I had a choice...lol

[jaydubya2003]

http://www.onlinecarstereo.com/CarAudio ... S6600.aspx

it is 2 ohm stable for the mids and highs but not rated for the sub at 2 ohms mono, 2 ohms stereo.........

I was just looking at that same listing for the amp...lol

Either way, no matter if it's stable at 2 ohms or not I will not be running it there if I can fix it because I don't want to have any problems.

So I will get the pictures up so I can get some more advice, and possibly see where to go from here.

[ttocs]

I think you might have looked at it wrong, it is rated at 4 ohm mono at 300 watts so you would not get any more power out at 2 ohm, just alot more heat. Look at the first line in the specs on the link I posted. I had to look at it a few times as well but it is NOT rated 2 ohm mono stable on the sub side.

[eulogious]

It sounds like you fried your output fets. I did the same thing on my tantrum 600.4 which is similar to your amp. The problem with the fets is that you usually can't tell if they are blown by just looking at them, you have to test them. In my repair thread I explain how to test them, but you have to remove them from the board to test them without special equipment. So ya, that where I would start...

[ttocs]

you were blowing fuses with the impedence too low which is normal. is it still doing it now with the correct impedence hooked up to it or have you tried that yet?

[Rold Gold]

You found white sticky stuff on it's bottom...........
You blew it's load..........

The manual reads alittle strang but it says "Minimun Speaker load, Bridged.....2ohm" right on page 3.
http://download.phoenixphorum.com/Manua ... xs6600.pdf

So basically you just got it hot too many times and now it needs a sandwich, something to drink and some Sports Center.........

[ttocs]

2 OHMS STEREO NOT MONO

[Rold Gold]

2 OHMS STEREO NOT MONO

But if you read what it says it's not exactly clear about that.....
It also says "Minimum Speaker load, Stereo.........1ohms" under that....

So I can see where the specifics get alittle grey.

MOVING ON.....................

[Bfowler]

i stand corrected...the manual does have a listing for 2ohm bridged...

i have had xs amps since they came out, and never had good experiences with them at 2ohms bridged.

the is from the old webfaq too:

How much power does an XS series amplifier provide at 2 ohms bridged?

The continuous power at 2 ohms or 1 ohm bridged remains about the same.

When designing the XS series amps, we wanted a design that made its best power at normal loads. By normal, we mean 4 ohms bridged. We know that no matter what we say, or how loud we say it - People will still hook the amp up to lower impedances trying to get more power. So, our number one goal is that the amp continue to operate at lower impedances. The only way to do that is to limit the continuous power output of the amp when it's hooked up to lower impedances. Here's why -

Wattage is equal to voltage times current. Running the amp at 2 ohms bridged means more output current. Current makes heat. We can't allow the amp to make more heat than the heatsink can reasonably dissipate. With the addition of cooling fans, the heatsink can manage a more heat than what's generated from a 4 ohm bridged load so there's some room for a bit more power. Here's how we limit the power increase to what's manageable:

The XS series amps have a circuit that detects the amount of current leaving the speaker terminals. If the current is high enough, AND lasts long enough (longer than 50 milliseconds), the circuit limits the amount of voltage that the power supply can produce. This in turn limits the power output of the amp. So continuous power output remains about the same with the power composed of more current and less voltage.

There is a bright side to all this. Remember I said that the excess current demand had to last longer than 50ms. The dynamic peaks in most music last less than 20ms. Therefore, the circuit never has a chance to affect the power supply voltage for musical peaks. All this means that the amp is allowed to make more power with musical peaks while continuous power remains about the same. You could say that the "headroom" of the amp is increased.

If you have to run the amp 2 ohms bridged, you can. Just understand that you must follow the above suggestions to make sure your amplifier isn't damaged or not operating correctly. I wouldn't recommend running it 1 ohm bridged. The amp will shut down (red LED) if the output current gets too high (looks like a shorted speaker).

so i guess what i'm getting at, is regardless of what the manual says....we have learned again that its not reccomened.


sucks the OP learned the hard way the manual is missleading

hopefully you can fix your amp, and not do that again.

you could also set up a cooling fan in a amprack, and get it capacitor. then it would likely survive your 2ohm option

[ttocs]

a confusing amp for sure.