# Meet the twins...



## vwdave (Jun 12, 2013)

Yea I know I got you to look with high expectations, but this is almost as good, right?









The PC2350 is an amp I've had for a while. I sold it to a friend, but he never took it as he's still planing his install. Recently I bought the PC21400 for a good price. I thought I'd give him this one instead and keep the 2350 for my collection. 

So I am replacing all power supply caps and rail caps on both. Once that's done they are getting sent for power testing to see if there's a difference in power between the 2.



















You can see which one is getting new caps right now...


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## vwdave (Jun 12, 2013)

More pics...

2350 is the one with the beefed up power supply. Part of the mods done for the Gates.


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## alm001 (Feb 13, 2010)

Yesssssss. I love the insides of those PPI amps.


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## vwdave (Jun 12, 2013)

I agree. They look great.

So on the pc2350 it was a good thing I changed the caps...

























And the twins hanging out with some cousins...


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## HKr1orion (Mar 6, 2014)

Dam, sure are packing some transistors! I like the rails instead of wires


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## vwdave (Jun 12, 2013)

HKr1orion said:


> Dam, sure are packing some transistors! I like the rails instead of wires


These are not dinky amps..1400Wrms at 4 ohms bridged on a class a/b.

They are 2 feet long...from the surfboard amp era. These amps were competitive with the Orion HCCA and Lanzar OPTIdrive amps back in the late 90s.


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## soccerguru607 (Nov 4, 2009)

2350 buss bar upgrade similar to my LP2.2hv

I sold a 21400.2 recently to CA, just wondering


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## 82cj8 (Jan 21, 2011)

Looks long !I remember those and I always wanted a pg zx .Back in late 90's it was the which is better ppi vs. PG .Is it hard to change out those parts?Looks tedious.


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## quietfly (Mar 23, 2011)

DROOL.....


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## vwdave (Jun 12, 2013)

soccerguru607 said:


> 2350 buss bar upgrade similar to my LP2.2hv
> 
> I sold a 21400.2 recently to CA, just wondering


I think that was me. Did you sell it on eBay? Your screen name looks familiar.



82cj8 said:


> Looks long !I remember those and I always wanted a pg zx .Back in late 90's it was the which is better ppi vs. PG .Is it hard to change out those parts?Looks tedious.


Yea I always was between ppi and pg back in the day, so now I saw why not both? The zx was always a favorite of mine, of course behind the zpa.

More tedious than anything. I'm fixing a zx474ti that looked like it caught fire. That one is more difficult to fix. Cap replacement is way easier than FET replacement or transistor replacement. I do have to say though that the ppi boards are easier to work with.


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## soccerguru607 (Nov 4, 2009)

Whoever bought that 21400.2 from me is an honest buyer who left feedback fast.


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## vwdave (Jun 12, 2013)

I just looked, it was me. I'm fastcarbuilder25. I also recognize your screen name from the Buyer/seller feedback section (I don't want to go back to that discussion though).

Good price on a great amp. I saw the crust on the cap but I didn't care as I knew I was changing the caps anyway. Very honest auction...not too common these days.


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## soccerguru607 (Nov 4, 2009)

Well, tyvm, you are an outstanding buyer yourself and left feedback so fast. I appreciates that. In the future if you have anything you like please contact me first, I can give you lower prices via direct paypal to save me eBay fees. Plus I will pay 3% paypal fees for buyer protection. Tyvm for your business.


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## soccerguru607 (Nov 4, 2009)

Oh, also I have seen Alma Gates kicker zr1000 which also have similar copper buss bars for PS. Maybe 2350 also build by him for competition?


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## ATOMICTECH62 (Jan 24, 2009)

Looks like the mosfets are damaged due to the burnt resistors(R53,R55,57).The HIP4080's will need replaced also.


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## soccerguru607 (Nov 4, 2009)

@atomictect62: I think they are HIP4081?

I would replace all 22ohm gate resisters and all new PS transistors also.
I would probably go with irf3205 x24. I would also check PS drivers mpsa06/56 pairing
Even if they are good I would replace them
Not cheap to repair PS on these amps.


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## ATOMICTECH62 (Jan 24, 2009)

The resistor next to the blue cap looks heat damaged also.
I would just do a complete rebuild of the PS.


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## vwdave (Jun 12, 2013)

soccerguru607 said:


> Oh, also I have seen Alma Gates kicker zr1000 which also have similar copper buss bars for PS. Maybe 2350 also build by him for competition?


It is my understanding that this was one of her amps. Her first system, the one that broke the world record, had 48 of these amps in her bronco. Someone wrote "26" on the front with a sharpie, leads me to believe that this amp was number 26. The manufacturing date seems to line up, and Brent (PPI-art-series-collector) has spoken to his people at PPI and they confirmed it. I never heard that the kicker amps had this same modification.



ATOMICTECH62 said:


> Looks like the mosfets are damaged due to the burnt resistors(R53,R55,57).The HIP4080's will need replaced also.


Oh crap. I didn't see that before. I actually did see it but I didn't pay attention, I thought they weren't resistors but diodes. Now that I look at my pics I see that they are resistors.



soccerguru607 said:


> @atomictect62: I think they are HIP4081?
> 
> I would replace all 22ohm gate resisters and all new PS transistors also.
> I would probably go with irf3205 x24. I would also check PS drivers mpsa06/56 pairing
> ...


Yea cheap insurance though.



ATOMICTECH62 said:


> The resistor next to the blue cap looks heat damaged also.
> I would just do a complete rebuild of the PS.


Ohhhh I didn't see that before...good eye in my blurry picture.

Was it normal on gees to be installed with a socket? The 21400 doesn't have sockets, but whenever I replace a chip on a board I use them, so I wonder if they've been replaced before...maybe another alma gates modification...

The amp powers up fine, but if I'm going to have it power tested i need to make sure it's in tip top shape. 

Once I've had it tested I'm taking it apart again, having the heat sink repainted and then making a display for it with the board out. It's not going to be used.


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## soccerguru607 (Nov 4, 2009)

Yes, there are two of them. I believe 2350, 21400 and pcx2400 are the only ppi amps use these HIP chips for PS.

Maybe just residue from fried PS transistors?


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## vwdave (Jun 12, 2013)

I dunno but I'm going to rebuild the entire power supply. I was already think it after seeing how the caps looked. This amp has for sure seen lots of use (or at least made lots of loud noise).

I'm no stranger to repairing amps...here's another one that I've been working on...









I've replaced all transistors, the burned resistors, and all of those tiny ceramic caps. I'm about to test it out...


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## shawnk (Jan 11, 2010)

vwdave said:


> I've replaced all transistors, the burned resistors, and all of those tiny ceramic caps. I'm about to test it out...



Good work cleaning all of that up. But you'll want to replace "all" of those emitter resistors for that channel. They really need to be absolutley identical to promote proper current sharing. You may have crossover distortion (although likely inaudible) without matching emitter resistors. Worst case scenario, you could cause a thermal runaway effect.


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## vwdave (Jun 12, 2013)

That makes sense Shawn. I was afraid that was the case.

Btw it drives me up the wall that I couldn't line up those resistors the way the factory did. The burned board was distorted though and this was the closes I could get. It looks like I'll have another go at it. I bought those should be 2w resistors but I got 1w resistors because that's what I found that was the right size. Well I found 2w resistors that are the same size so I'm replacing all of them.

My digikey order just keeps growing. 

What I didn't mention before is that I have rail caps coming for both the 2350 and the 21400. The ones on the 21400 are bulging really bad and the ones on the 2350 are starting to.


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## vwdave (Jun 12, 2013)

Update...I replaced the rail caps on the 21400 as they were bulging...

I got the same value as factory but abviously a different brand. I couldn't find the same brand, but the two amps had different brands to begin with. Once I'm done they will both match as I'm doing the 2350 as well.














































All of the replaced caps...









And with that, I'm done with the 21400 (of course I need to set the DC offset). It's now waiting on its brother to be finished and then they go for power testing.


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## soccerguru607 (Nov 4, 2009)

Very nice clean job!


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## vwdave (Jun 12, 2013)

Thanks. It helps when the amp is clean.

Now, on to the less clean amp...and hence a less clean job.

First, the rail caps...




































Now, on to the repair of he power supply...

After FET removal, before clean up


















After clean up...


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## RandyJ75 (Dec 4, 2006)

Very interesting thread Dave; any updates?


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## vwdave (Jun 12, 2013)

Yup...now there are 3.









The latest one I bought as a parts amp. When it arrived a few things were not as expected. First, it was missing the bottom cover. Second, the damage was superficial (at least to the board) and was totally repairable. I have now replaced all blown parts, cleaned up the charred board, and I am now making the pieces to convert it to a plexi bottom amp.

Once all is said and done the 2350 will be repainted to new condition and I am selling the 2350 and the latest 21400.2.

Here's some progress from start to current on the latest 21400.2.
Before...

















During...

























Current...


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## soccerguru607 (Nov 4, 2009)

Very nicely done!!!


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## 2010hummerguy (Oct 7, 2009)

Wowowow I love these big PPI mushroom amps, my PC6600 was one of my favorites 10 years ago. Those new caps look GREAT! This is my kind of porn  Planning to clamp them after the refurb?


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## vwdave (Jun 12, 2013)

soccerguru607 said:


> Very nicely done!!!


Thanks.



Architect7 said:


> Wowowow I love these big PPI mushroom amps, my PC6600 was one of my favorites 10 years ago. Those new caps look GREAT! This is my kind of porn  Planning to clamp them after the refurb?


Thanks. Clamp them? I'm building rails that will properly push the transistors against the heatsink. Then I can properly test the amp.


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## 2010hummerguy (Oct 7, 2009)

Yeah, by clamp I meant bench test. Can't wait to see what the 21400 does.


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## vwdave (Jun 12, 2013)

Ah gotcha. We shall see.


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## thatdrh (Nov 28, 2009)

*PC21400.2*

Anyone happen to know what the voltage should be on rails of a 21400.2? I just got the power supply fets, gate drivers and resistors changed... its now functons... but during testing it cooked a CAP. So I replaced the Caps... Those just popped as well.. during this, it was still producing sound... any thoughts?


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## thatdrh (Nov 28, 2009)

Can you give me a reading of the voltage on the rails is, please? I have one here, thats running around 95 volts...It also happens to be popping my caps. I may have a hot running power supply after changing my fets, gate resistors and new gate drives. Its driving me nuts.

Thanks.


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## thatdrh (Nov 28, 2009)

I was just reading my question... Looks like english left the building..


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