# Repairing a ppi pc2350



## vwdave (Jun 12, 2013)

So I bought the 2350 on eBay with intentions of repairing it. I see that it was modified. Some resistors were changed and some wires run the the end cap hooked to a switch. Any idea of why this was done? 

I would like to put it back to stock. Does anyone have a 2350 that could look at the board and tell me what the resistors should be?

I can supply pics if needed.

It looks like they changed R60, R205 and R13?(it's under the bus bar between Q16 and Q17)

Oh, it's serial number 0003 and someone wrote on it with a sharpie "26" next to the serial number. Could this have been used in the Gates' bronco?

Thanks


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## vwdave (Jun 12, 2013)

no takers?

someone out there HAS to have one of these amps. can you please take a quick look and help a fellow car audio freak out? I want to get this repaired already.


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## Ampman (Sep 7, 2011)

Must be referring to one of these  ill check it sometime tomorrow if I get a minute and let you know.


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## Ampman (Sep 7, 2011)

I got a reading outta the circuit for resistor 13 of 117.3K which I believe my meter is off quite a bit should be more like 118K judging by the colors. Resistors 205 & 60 are 820 ohm. Hope this helps


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## vwdave (Jun 12, 2013)

Thank you so much!!!

How do you like the amp? I love the pc series. I used the 250 and 275 for a while so I couldn't pass up on this one.


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## SaturnSL1 (Jun 27, 2011)

Power Class is the bees knees baby. I'm about to swap my Alpine V12 out for my PC450 that was originally in there. Can't beat how clean the amp sounds.


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## vwdave (Jun 12, 2013)

I agree...i really like the PC class.

I ordered the resistors...i hope they arrive by monday as I have the day off and I would love to get it repaired.
so here are some pictures of how the amp sits now:


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## vwdave (Jun 12, 2013)

I cant wait to get those horribly soldered resistors out and the board cleaned up. It looks like whomever modified the board didnt even remove it to replace the resistors.


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## vwdave (Jun 12, 2013)

Ampman said:


>


are those two stripes red or brown. I assume that since you said you measured 117k that you are right about it beeing 118k.

the 820 resistors will be 2% tolerance rather than 5% so its improved, and the 118k is 1%. I couldnt see that stripe on that one, but im sure its not better than 1%.


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## Ampman (Sep 7, 2011)

I like the PC series amps. I've got 2 of them, I found out if you dont have really good subs hooked up to these things, they have a tendency to take them apart  and I'm ain't referring to the box their in, the sub it's self lol mine blew the speaker surrounds out. Never have burned a voice coil though cause I never got that far hehe. I was using 12's though lol their tuff amps. You'll love it


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## Ampman (Sep 7, 2011)

I've got 2 PC 2350's sorry didn't specify. One PC 2150 one PC 250 one PC 450. Really cool amps


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## Ampman (Sep 7, 2011)

To answer your question about R 13 from what I can see its 2 browns.


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## vwdave (Jun 12, 2013)

and a 2350? lol

Im actually not using it in my install. Havnt decided what to do with it, it depends on if I can find out if it was used in "the beast". It might just be a part of car audio history, in which I will just "collect" it.

Im running another old school amp in my system, McIntosh MC-440. Im keeping this install simple. Not sure why considering I have a PG ZPA0.5 and this PC2350. Maybe I will put it into my wifes Prius V .

So would this amp run a pair of 12w7s?


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## Ampman (Sep 7, 2011)

You running it mono or stereo ? A buddy has a PC 2350 he's using it on 4 RE Audio 12's. the first 5 he had the thing drove them so hard it broke the tensile wire in half just rite before it connects to the voice coil and on one of those subs it damaged that speakers motor structure so might want to be a bit careful how much you turn it up, I blew the surrounds apart on 3 sets of subs with mine I told my buddy that amp would he didn't believe me, he dose now hehe


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## SaturnSL1 (Jun 27, 2011)

Damn, didn't realize the specs on that amp. Shes a big *****. Reminds me of my USA400.

I'd totally utilize that in an install dude. If it can run full pass I'd even use it on some mids and highs. I know my USA sounds beautiful on decent speakers, I'm sure that 2350 would sound even better!

Can you say "headroom"?


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## Ampman (Sep 7, 2011)

I hooked mine various ways, which ever way you choose you'll need speakers that will handle 
what that thing puts out. Not saying its the most powerful full range amp out there I just know what mine done to decent subs an components lol it's one mean amp.


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## vwdave (Jun 12, 2013)

Im sure I will find a use for it. My daily driver is staying as a basic system but Im thinking in the future I can use my PG ZPA0.5 for components and this 2350 to run a 13w7 maybe?

Im currently using a McIntosh MC440 and I want to keep that as the sole amp in my daily driver. 400 is enough to run a good SQ sub.


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## vwdave (Jun 12, 2013)

Gee do I like surprises! lol...

Here is what I found on the underside of the amp. Not sure what this means, but i know its not normal on this amp...




Now, do I try to put it back to OEM status, or was this done to increase power for "the beast"? I am seeing more and more evidence that this was used for the SPL monster owned by Alma Gates. This does not look like it was done by an amateur. whomever did it had the ability to cut the copper, and knew what they were doing. The soldering could have been done neater, but the concept looks to be solid. The yellow jumper cable seems to make the amp in mono mode permanently, i could be wrong.


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## SaturnSL1 (Jun 27, 2011)

What the **** is going on with that thing? lol


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## alm001 (Feb 13, 2010)

Didn't the beast use all PC1400s?


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## SaturnSL1 (Jun 27, 2011)

alm001 said:


> Didn't the beast use all PC1400s?


No it used 2350s


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## alm001 (Feb 13, 2010)

SaturnSL1 said:


> No it used 2350s


You are correct, sorry.

From Alma herself;
"The only PPI amps used in the Bronco were the old art series in 1996 PPI replaced them in 1997 with the 2350s."

But they were wired for mono.

(I had one of the subs, and one of the DEQ-230's from the beast)


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## vwdave (Jun 12, 2013)

alm001 said:


> Didn't the beast use all PC1400s?


Ive found conflicting reports. I always thought they were 2350s, but I found a thread on here from years ago that claimed 1400s. The 1400 looks too small to be in the pictures of "the beast". I think that was an empty rumor.

PC 1400 (about 20 inches, look on the left, it started at 1"):









PPI Beast:

























So look at where the amps are in relation to the height of the amp racks, car lines and such. You have in the amp rack height 2 10" subs, the amps come to the same height as the subs, but go about 4" down below the body line. The 1400 would be too small to fit this dimension.

...the amp must be at least 24" long. The 2350 is 24" long.


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## vwdave (Jun 12, 2013)

alm001 said:


> You are correct, sorry.
> 
> From Alma herself;
> "The only PPI amps used in the Bronco were the old art series in 1996 PPI replaced them in 1997 with the 2350s."
> ...


wired for mono...is that the yellow jumper that I found inside?

The more I think about it, those bus bars probably make the amp 1 ohm stable. If i read correctly, people say that the amp isnt 1 ohm stable. They say it cant handle the power. those bus bars and 12 gauge wire would fix that.


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## SaturnSL1 (Jun 27, 2011)

http://img.photobucket.com/albums/v736/SPL2k/gates1.jpg

You are probably right about the little yellow jumper. There really wouldn't be any other reason to do that to the RCAs.

That's one sweet piece of history you got man


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## Ampman (Sep 7, 2011)

Yeah that's what yellow wire is all about. Guess so they could use just one RCA instead of two. Whoever modified the trace for the fets did know what they were doing for sure. Was there anything connecting to the ground side of the fets made up like that of sorts ?


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## vwdave (Jun 12, 2013)

You see all that was there.


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## Ampman (Sep 7, 2011)

Had to look at mine didn't remember they used rails for the ground.


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## vwdave (Jun 12, 2013)

SaturnSL1 said:


> http://img.photobucket.com/albums/v736/SPL2k/gates1.jpg
> 
> You are probably right about the little yellow jumper. There really wouldn't be any other reason to do that to the RCAs.
> 
> That's one sweet piece of history you got man


Is that all your stuff? If so, do you mind just opening the bottom up real fast and seeing if you have those modified resistors as well? or even easier, look on the endplate for that added switch. I am now starting to wonder if they added that switch or if that was done later.

BTW heres what I am talking about...


I assumed that the switch was added later because it was added at the same time as the resistors. It appears that the resistors were done by someone who didnt remove the board considering how they were put in. The switch had a pair of wires going from the switch to one of the modified resistors. The switch seemed to toggle between two different resistances, possibly effecting the current of the amplifier? I am just so confused so I hope to get to the bottom of this.


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## SaturnSL1 (Jun 27, 2011)

Nope thats not my stuff, sorry man.


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## vwdave (Jun 12, 2013)

So I got the resistors replaced with the OEM value resistors. im going to test it for power up soon to see what it does. Anyone advise me to change the power supply caps? They dont appear to be leaking and I dont think these tend to have an issue like the PG ones.

damn PPI used so much flux it still burning on there how many years later...?



sorry these arent too focused my iphone isnt the best and I dont have the right lens for me dSLR to get a closeup to focus...


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## TrickyRicky (Apr 5, 2009)

That resistor doesn't look like the right value (correct color stripes) according to the one above it. Get a 15x hand held magnifying glass/loop and you'll get crystal clear close ups.


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## vwdave (Jun 12, 2013)

Let me take a look when I get home. It might just be bad lighting. I dunno sometimes I can get my dSLR to focus and sometimes not. I really hope digikey didn't screw up and send the wrong resistors. The final stripe will be different as I got 1% tolerance versus 5%.


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## vwdave (Jun 12, 2013)

Looks like digikey screwed up! Good catch I was half asleep. I'm having trouble reading the stripes but my trust dmm reads 300 ohms and 14k, not even close.


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## vwdave (Jun 12, 2013)

So Digikey is sending me new resistors. Funny thing is, I saw two of the resistors that were smaller than expected and i kind of scratched my head...and still I didnt verify the values.

No harm, no foul.

So I decided that while waiting for the new resistors I decided to try and polish up the heat sink a little bit. Theres not much I can do about all of the scratching as repainting it would loose the original silk screening. It is in rough shape, but i hope that I at least made it look a little shinier. I used Insta Finish Micro Cut and Premium Polish. I did it all by hand with a soft cloth, so Im sure it would be better with a buffer, but its not worth it for me to go out and buy one for just this project.

Before:



After:





Even if it doesnt look better, at least its cleaner and smells good (cherry).


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## TrickyRicky (Apr 5, 2009)

That last sentence reminds me of a old school Sony amplifier someone sent me for repair.....it smelled like someone had placed a "small" scented tree inside.


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## Ampman (Sep 7, 2011)

Have you considered using kapton tape for the transistor insulators. Here's a pic of before and after doing my PPI 2150AM


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## vwdave (Jun 12, 2013)

that tape looks promissing. do you still use thermal paste with it or was that left over from before?


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## TrickyRicky (Apr 5, 2009)

I use very little thermal compound when using Kapton....but just between the tranistor and Kapton, not between the Katpon and the sink.


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## vwdave (Jun 12, 2013)

that might be the way to go. it still has the same thermal properties? I just want to make sure that if someone uses this amp that they dont blow it up.


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## Ampman (Sep 7, 2011)

Still gotta use the paste, advantage of the tape is its thiner than the mica that's in it, it will help transfer the heat faster.


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## Ampman (Sep 7, 2011)

How is the PPI coming along ?


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## vwdave (Jun 12, 2013)

I haven't had time to work on it. The correct resistors arrived but they are just sitting in the bags. I am a little confused on the 820 ohm resistors. They are smaller than the others but are supposedly the same power rating. Also, I can't say for sure because they are so small but the color codes look to be incorrect. Funny thing is, my multimeter says they are correct.

I will swap them out this week sometime and I hope to test it with power by the end of the week.


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## Ampman (Sep 7, 2011)

I know that, not having time. I get a lot of my amps in non working order to save on cost, I put um in the group to do when there's time. Most wont get done for a while due to not having the extra time to mess them. So take a break drink some tea and enjoy life, it'll be there when there is time. I know it will be a great amp.


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## buccnation07 (10 mo ago)

vwdave said:


> no takers?
> 
> someone out there HAS to have one of these amps. can you please take a quick look and help a fellow car audio freak out? I want to get this repaired already.


Yes i have one i can tell you that it isnt stuffed like that gotta be one of alma gates amps


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## buccnation07 (10 mo ago)

vwdave said:


> and a 2350? lol
> 
> Im actually not using it in my install. Havnt decided what to do with it, it depends on if I can find out if it was used in "the beast". It might just be a part of car audio history, in which I will just "collect" it.
> 
> ...


That amp will push whatever and u have a one of a kind 2350 or 1 of 4 mine has pushed and would blow **** and was so clean u wouldnt even know it was blowing them


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