Please help with wiring of my MS2125's

[Lance_S]

Hey Pimp,

Do you happen to have a pic of the faceplate of the 2125 you listed? The reason I ask is that both of my amps when you read the faceplate where the speaker terminals are read Left - + Right - +.

Now, when I pull up the owners manual on this site it reads the same but when I look at the physical owners manual that comes with the amp it reads Left + - Right + -.

Obviously there were some changes along the line. I think it just makes sense to hook them up to match the speaker terminals. Run the pos to the pos and the grounds to the negs. Again, I am talking speaker terminals here, not the power and ground to the amp itself.

[ttocs]

all you need to do is swap the wires at the back of the terminal man. They will not stick out and look funny and will still play fine.

[Lance_S]

Yup, that's what I was planning on doing. I still think tho there is something amiss with the gray one sending voltage through the rca. I am going to yank them both, correct the speaker wire connections to the appropriate pos and negs and then bench test it and see what I get.

[pimpinest123]

2125

[ttocs]

I would check your solder connections. It would not be hard to leave too much on the back and then have it short out.

[Lance_S]

Thanks Pimp.

Ttocs,

Yeah, I know. The thought of taking that thing apart again makes my blood boil but your right, I am running out of obvious answers. Maybe I will pull it apart and take a pic and post it. See what you guys think.

L

[Lance_S]

Pimp,

BTW, Your right channel is out of phase! . What is it with PG and speaker phase. Am I missing something? If you look at the pick that Pimp posted on the first page of the thread (last pic) you will see the speaker positives go to the outside. So if you flip it over it would be L + -, R - +. That's why I asked him to post a pic of his faceplate, which reads L + - and R + -. His Right speaker out is flipped.

I have pulled about 4 different pics of different 2125's from the web. There is none of them that are all the same. I guess they changed it from version to version but it still doesn't make sense that none of the ones I have seen match the faceplate outs.

[ttocs]

I would not be suprised if that when you take it apart you notice the points where it made contact.

[00goobs]

Pimp,

BTW, Your right channel is out of phase! . What is it with PG and speaker phase. Am I missing something? If you look at the pick that Pimp posted on the first page of the thread (last pic) you will see the speaker positives go to the outside. So if you flip it over it would be L + -, R - +. That's why I asked him to post a pic of his faceplate, which reads L + - and R + -. His Right speaker out is flipped.

I have pulled about 4 different pics of different 2125's from the web. There is none of them that are all the same. I guess they changed it from version to version but it still doesn't make sense that none of the ones I have seen match the faceplate outs.

They do that so you can run the amp in stereo and bridged at the same time. They just inverted the signal on one channel. If you bridged the amp using conventional L- & R+ you'll be using only the right channel assuming the internal amp ties the L & R - together....

Hello from my phone!

[Lance_S]

00goobs,

Can you explain that to me? Are you saying if you want to run the amp bridged that it should be wired like that? Sorry, I am not quite following your logic.

Thanks.

L

[Lance_S]

BTW,

I have narrowed the problem down to the gray amp. The 275 and the white 2125 are fine and output as normal. I did find a bad RCA connector but it was on the 275 and wasn't the problem of the meltdown. Now that I have tested the 275 and the white 2125 I am going to pull the gray 2125 and dig into it. I try not to use much solder when I did the caps but I guess there is a chance I went out and hit the board on one of the connections. I will know more when I have it apart.

I did smoke my 9887 so if anyone has one laying around they aren't using I would be interested. Man it sucks to loose a head unit due to an amp problem.

Lance

[Lance_S]

Here are some pics of the gray one before I pull it apart.....again. I don't see anything glaring but I wanted to see what you guys thought. Any obvious problems????

[00goobs]

00goobs,

Can you explain that to me? Are you saying if you want to run the amp bridged that it should be wired like that? Sorry, I am not quite following your logic.

Thanks.

L

Inside of the amp, the speaker output grounds are the same as noted on the board (not at the terminals). The left and right outputs on the board swing from + (0-40volts) and - (0-40volts) depending on amount of output. To be able to use the output in stereo and bridged at the same time, you'll need to use both the speaker outputs (internally on the board) to the bridged speaker and the outputs have to be at a different voltage. So, the PG amps invert the output signal on one side in relation to the other to do this. Without inverting one channel, the outputs would be identical and there will be no voltage difference and the speaker will not move when bridged from one output to the other. The reason the speaker outputs are opposite on one side versus the other outside of the amp at the terminals is that inverting the output on one of the 2 channels will put the speakers out of phase between the left and right which will cancel some of the sounds coming out. To get the speakers back in phase, you would hook either channel opposite to the other. It is probably best with pictures, so I'll try something....



This is my white MS2125 with blue/silver twist speaker wires. My grey was different slightly....

[Lance_S]

ok,

wife has the camera so I had to post from the crackberry. Hope these are good enough for analysis.

Pics of both sets of caps from the back.

There is nothing else I see out of the ordinary, no burn marks, etc.

Some of the solder joints do have alittle dirt in them from the iron, but they aren't burn marks in case your wondering

[Lance_S]

00goobs,

L

Inside of the amp, the speaker output grounds are the same as noted on the board (not at the terminals). The left and right outputs on the board swing from + (0-40volts) and - (0-40volts) depending on amount of output. To be able to use the output in stereo and bridged at the same time, you'll need to use both the speaker outputs (internally on the board) to the bridged speaker and the outputs have to be at a different voltage. So, the PG amps invert the output signal on one side in relation to the other to do this. Without inverting one channel, the outputs would be identical and there will be no voltage difference and the speaker will not move when bridged from one output to the other. The reason the speaker outputs are opposite on one side versus the other outside of the amp at the terminals is that inverting the output on one of the 2 channels will put the speakers out of phase between the left and right which will cancel some of the sounds coming out. To get the speakers back in phase, you would hook either channel opposite to the other. It is probably best with pictures, so I'll try something....

Cool thanks.

My intention is to run one in stereo but I want it in phase so you are saying to hook the pos to pos and neg to negs right? I also want to run one bridged, but not in trimode, just simple bridged. So this is where it get confusing. The manual says to run Left + and right -. Is that actual pos and neg or the way they have it wiring from the factory....which really isn't pos and neg.

Thanks, again...a bit confusing.

lance

[Lance_S]

00goobs,

Cool, got it. Thanks.

Lance

[Lance_S]

OK,

I think I have located the problem. The following 2 pics are the back of the board where the diodes for the gain and the bass boost come through the back of the board. There is a sheet of plastic that seperates the heat sink from the back of the board. It looks like the pronges from the gain and bass boost that come through the board weren't snipped off. They are too long and shorting out through the plastic sheet and onto the heat sink.

That is my guess, someone correct me if I am wrong. The cap leads looked a hair long to me too so I snipped those down just to make sure. I am going to snip the nubs down and put something between the nubs and the heat sink to make sure it won't touch, put it together and test it.

Thanks.

Lance

[tattooemil]

same strange shit with my 2125



looks like my RIGHT has to be swapped???

finally....how do i bridge it correctly? would that be the left(red-internal) wire and the right(black-internal)wire???? or would it be the 2 red wires(internal)??

[tattooemil]

bump.....anyone??? how do i bridge it correctly? would that be the left(red-internal) wire and the right(black-internal)wire???? or would it be the 2 red wires(internal)??

[00goobs]

bump.....anyone??? how do i bridge it correctly? would that be the left(red-internal) wire and the right(black-internal)wire???? or would it be the 2 red wires(internal)??

I say the two red wires...


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