Please help with wiring of my MS2125's

[Lance_S]

So after many hours of installation and recapping the infamous time came to put the power to it. And.....smoke started pouring out of my deck at the RCA jacks as soon as I put power to the amp distribution block. Mind you, I haven't yet turned the head unit on. No power to the head unit at all and smoke is billowing out the back of the head unit.

I started to look at how the amp was wired and where the pos and neg went from the board to the speaker outs and here is what I found.

On the Gray amp, which uses the red and black internal power wire. The gnd and pwr wires don't go to their respective pos and negs on the speaker hookup. If you read the front of the 2125's the speaker hook up is L - + R - + but if you follow the wiring from the board to the speaker outs it goes L - + R + -. So the polarity is switched on the R channel on the Gray amp. When the gray amp is hooked up to the distribution block and I touch the hot lead to the battery is sparks even when the amp is off.

On the White 2125, which uses the newer style internal wires the gnd and power wires don't go to their respective pos and neg either, but on this one it's different. Again, if you read the hook up on the face plate it reads (like the grey) L - + R - + but if you follow the wiring form the board to the speaker outs it goes L + - R + -. The polarity is swapped on both the Right and the Left speakers.

So I decided to check my MS275 and guess what I found:
On the 275 the face plate speaker output reads L + - R + - but if you look at the pic where the 4 wires (2 red and 2 black) are running together toward the speaker outs they go R + - L- +.

I have no idea what the hell is going on. I do know that I smoked a perfectly good Alpine 9887 in the process of all of this mess. I can't for the life of me figure out why in the hell PG would do something like this. Can some help me and tell me how my amps should be run internally. Obviously something is very wrong with my amps.

BTW, the first pic is the 275, the second is the white 2125 with the newer internal wiring and the third is the grey 2125 with the traditional black and red internal wiring.

Thanks in advance.

[ttocs]

sounds like you sent voltage back up the rca's into the deck. Are you sure you have the power wires and speaker wires in the correct place and do not have them switched? Maybe someone else can post pics of theirs to see if they are in the correct place.

also looking at the caps... I thought it was basically two mono amps put in one chassis so flip one over and you can check the other. IF that is the case, wouldn't two of the caps face the opposite way? Lookin at the stripes on yours it looks like they were put in as though the amp is not flipped. I think the capson the bottom are on backwards..........?

[Lance_S]

Yeah, I even pulled the speaker wires off the amps and checked them again, still the same problem.

I also took before pics of the amp and the caps, all the stripes faced the same way.

Thanks for the help.

[pimpinest123]

ms 2250 then mps 2240 then ms 275 then mps 2500 then ms 2125

[Lance_S]

hmmm,

then both of my amps are wired wrong if the last one is a 2125 and it's working properly. I don't get it. I never changed the wiring in the amp, just the caps. I never undid the connection, I kept it connected to the block when I swapped the caps out. I just don't understand how both of my amps could be wiring wrong from the factory. They were BNIB so i guess it's possible since they haven't ever been fired up before.

Just unbelievable.

Thanks for the pics.

[pimpinest123]

Yes it is a 2125 and works

[ttocs]

oh hell those are backwards huh? Looks like someone took them apart at some time.

[Lance_S]

Yeah, looks like I have some reworing to do. I hope the amps are ok. I never fired them up and there is no damage to the amps that's visual but I am pretty sure my hread unit is shot. We will have to see.

[ttocs]

now be aware that there are different revisions of that amp and they might have switched them. Someone with more experieince in that line like eric would probably know best I am sure he will be here shortly.

[Lance_S]

Ttocs,

I agree but if you look at all of the pics of the amps (not mine) they all lay out ther same way. Pos, neg,neg,pos. Even on the smaller ones. They are all the same. The thing that confuses me is that on the 275 the speaker connection on the faceplate lists pos,neg,pos,neg so I am still confused as to why the pos and negs from the board to the input on the faceplate don't match up????

[todd217]

if im reading this correct you wired the power wire to the red and black wires and not the gold bars in the center.

[Lance_S]

no, I hooked up the power and ground properly. Look at the guts of the two 2125's that I pictured at the top and look at where the red and black wires run from the board to the speaker outlet, now look at the pics of the 2125 that Pimp listed. You see his run pos to the outside, neg to the inside? Mine don't run like that. The pic of the 2500 runs the same way, pos to the outside of the chassis and negs to the inside.

But here is the strange part. When you flip the amp right side up and you are looking at the face plate. It will tell you Left - +, Right - +. So it doesn't make any sense. From the board the positives are running to the outside of the chassis but if you look at where they come through on the face plate you have a Left - and a right +. But from the board it's really two positives.

Now, if your going mono. The manual tells you to run Left Positive and Right Negative. Which from the board would be two negatives!!!! I don't get it.

Sorry if this is confusing. It's confusing to me too. Either way, I will wire them up in the same manner that pimps picture shows and see what happens.

[todd217]

you had me confused with the whole red black thing. so you put the batt+ and batt- the way they were listed on the outside of the ms2125s. looking at the amp with the heatsink up left to right shoud be batt- batt+ remote this is how you did it right?

[ttocs]

but wiring speakers out of phase, or backwards will not hurt anything, didn't think about it just noticed the differences. unless you had it wired mono or something I can't see that smoking the deck,

[todd217]

but wiring speakers out of phase, or backwards will not hurt anything, didn't think about it just noticed the differences. unless you had it wired mono or something I can't see that smoking the deck,

scott i thought he put power to the speaker terminals.

[ttocs]

i know you understood, I was wondering myself. I was just letting him know that speakers out of phase might sound different but would not cause any magik smoke.

[Lance_S]

mmmmm,

sorry guys. I didn't mean the power side of the neg and pos. I meant the speaker outs. So if they are out of phase it wouldn't send smoke to through my RCA's what would. Damn. I was hoping it was going to be as easy as getting the polarity correct on o the speaker outs. Now I am at a loss. Both of my 2125's have grounding problems of some kind. When I hook them up, I get sparks off the battery when I try and connect the positive line. I can easily correct the polarity of the speaker outs but I still don't know if that will help the grounding issue.....if there is one.

Thanks,

L

[ttocs]

all it would do is when the speaker was supposed to move forward, it would move backwards. You would only really notice if one was out of phase and the other was normal. You would wire ever single speaker backwards and then they would all sound the same and cause 0 damage to anything.

still sounds like you sent 12vdc back to the deck in one way or another which means something is desperatly wrong.

[Lance_S]

The only other thing I did was swap caps. I don't know how that could do it..... I ran a hot, a cold, a remote...but it even did it when I ran it without the remote. Just the hot and cold hooked up sent heat back through the rca.

[oldskoolmseriesfan]

maybe this thread should be brought to the attention of nico boom... hes the king of anything ms related

[ttocs]

it doesn't take more then a scrap piece of wire in the wrong place or maybe a solder connection that is too big and grounding out to the chassis? I would take it back apart and go over it with a magnafying glass personally.

[Stryker]

This is obviously not going as planned, I think you need Valeks1 to chime in on this one. He would actually know what to do.
It seems to me that there is a whole lotta guessing going on. I have not ever read/heard about 12v goin backwards into the deck through
the RCA's, seems more like a very complex problem rather than a simple fix here. I hope I'm wrong but....

[ttocs]

normally the RCA's melt with any current on that 12v, I have only seen it once and it was when an amp got a little wet.

[00goobs]

I looked at one of my 2125s and noticed your RCAs on the pic below go under the bus bars and are soldered to the middle of the board above the Phoenix Gold logo. I checked and my MS amps and they go to the side below the stereo/bridged switch... I don't have an MPS2500, so it could be nothing....



If your first opamp has a stray wire or something conductive inside of the amp shorting it to the input wires, it could send +/- 15 volts through a 10k ohm resistor to the head unit. I would guess that your RCA cables may have been pinched with a power wire somewhere before the amps.

[Lance_S]

I ran the power down one side of the car and the rca's down the other side to avoid noise. They never meet. Even the remote hot is run on the left side of the car. I can try switching rca's but I don't think it's that. I will check it.

The power bus rods have a plastic cover over them so even if something should touch them they should be insulated. I am going to pull the amps out of the rack and start looking them over. I am also going to set up a separate head unit to test the amps individually. I think the one that is causing the trouble is the gray one (the one with the red and black internal speaker cable).


edit: I also have another question about phase. I realize that if they are out of phaze it wouldn't cause the system to feed power back through the rca, which i believe is happening. And I believe it's only the gray 2125, the white one didn't do it. But my question is this, won't it affect when you try and run it mono? Doesn't a mono switch make a hot and cold dependent on each other? The gray one IS running mono so wouldn't the polarity matter?

Thanks again.

Keep the ideas coming. I appreciate them. I will get this figured out yet.

lance