# I need some help here so I dont blow up this amp. install this RCA jacks



## JAX (Jun 2, 2006)

I got the old ones out. I decided screw trying to find a replacement..I am going to do the rca upgrade myself. came out easy enough.

Now I have 4 holes in the pcb. I dont know if 2 of them are just to stabilize the jack or if it is related to the connection. pics will show what I mean. there is a "+" and a "-" 

the old rca had 4 legs but like I said 2 of them might just be to hold the rca in place. 

please lend a hand as I want to get this done and re-assembled. but I want it right. cant afford to jack up a perfectly good amp with a minor issue


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## Austin (Mar 12, 2009)

It's a bit hard to tell but is that location just a single rca plug?


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## JAX (Jun 2, 2006)

more pics of the backside


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## JAX (Jun 2, 2006)

Austin said:


> It's a bit hard to tell but is that location just a single rca plug?



yes, its for the rear inputs. the jack worked but the internal insulators were busted out and the rca jackets were loose. going to install tiffany style nut mounted rca inputs there..havnt decided on the other . if I can do this one then maybe the other 4


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## BoostedNihilist (Mar 3, 2008)

continuity beeper should tell you everything you need to know.


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## JAX (Jun 2, 2006)

BoostedNihilist said:


> continuity beeper should tell you everything you need to know.



ok,what is that? meter?


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## BoostedNihilist (Mar 3, 2008)

yeah lots of times the meter will have a little speaker on there somewhere.. when you touch the leads together they beep. Once you get them to beep you can see which legs are connected to which parts of the RCA and if they are isolated.


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## wheelieking71 (Dec 20, 2006)

ya, meter. i think the + marks on the top of the board are referrng to the capacitor polarity. not the RCA? you should be able to use a meter wth a continuity check and determine whick hole in the PCB is what. probe the shield of one of the RCA jacks, and start probing the legs on the back till you find its mate. then whatever hole in the board corresponded to that leg, is that channels negative. then repeat 4 times till you know what everything is.


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## Therum (Apr 18, 2009)

Or just use a meter set to check resistance (Ohms) and with the above statement finding its mate is just finding which combination says 0 ohms. Or you can probe the solder pads on the board and find which 2 are tied together. That will be your ground.


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## BoostedNihilist (Mar 3, 2008)

so, get it figured out?


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## JAX (Jun 2, 2006)

not yet. I havnt tested it yet. been busy. I have to wait for my son to go to bed or else he will end up breaking something when I am not looking. cant have him snapping off a resistor or something while I am not looking. maybe later if I can


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## BoostedNihilist (Mar 3, 2008)

true that. Good luck


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## JAX (Jun 2, 2006)

soon as I fix it then I am selling it. I dont think I want cords hanging out one end. although it would be a solution.

wonder how come no amp I have ever seen is like that? like old decks used to have rca cords...how come no amp has ever had rca cords? then you would never have that broken rca issue again..


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## BoostedNihilist (Mar 3, 2008)

think headphone plug. every design has a weak point. I personally thing recessed jacks are the way to go.


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## JAX (Jun 2, 2006)

I think I got this in my head figured out...but to be sure...

outer jacket of rca jack is negative ground. yes. figure out which to legs are grounds then I will know which 2 are positive. should be easy..as long as the jacks are too jacked to read correctly ..

1 of my meters does have the beep beep he he


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## BoostedNihilist (Mar 3, 2008)

yeah, jam a probe inside the rca jack and then test the legs, the ones that beep are positive


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## JAX (Jun 2, 2006)

BoostedNihilist said:


> yeah, jam a probe inside the rca jack and then test the legs, the ones that beep are positive



I am not sure the condition now of the insides but the outside casing should be fine so if I test for the negatives then its pretty easy from there to figure which is left and right positive 

thanks for the tip on the beeper..never actually knew it had it till I tested it. 

I got it figured out. just need to get chance alone to sort it out and mark it then attach my wires to the board and rca jacks. 

from here it is easy thanks to the help.

I may replace all 6 now that I figured it out but I need to see if they will fit with the nuts being that they are somewhat close. but I can take the outer plate and do a test before removing any other jacks off the board


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## BoostedNihilist (Mar 3, 2008)

right on, good luck with the repair... post up when you've got it fixed eh


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## wheelieking71 (Dec 20, 2006)

cool mod, post pics! hows thats ugly-duckling adcom JAX? pretty sweet sleeper amp huh!


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## JAX (Jun 2, 2006)

OK, got it all labeled on paper after testing all the legs. was a piece of cake for a novice with a meter like me thanks to the beeper..ha ha...

all I need to do now is get out the solder. I wanted to do it now but son is not going to bed without me ..freakin heck

Adcom is humming away. I need to clear my flash drive and put some new music on it so I can jam some more. sounds fantastic. I am McLovin it

have no regrets on pulling the Jbl for the adcom. I just wish I had the funds for that 5450 but then again..there is a 4404 somewhere calling my name


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## BoostedNihilist (Mar 3, 2008)

A trick for the future.. if you want to desolder something.. tin a TINY bit of wire, put the wire on the solder pad and reheat your tin job, cheap mans solder wick right there.


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## JAX (Jun 2, 2006)

done. outside looks much nicer...inside..you will never see if I can help it..now to test it out


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## Ziggy (Nov 29, 2007)

holding breath... crossing fingers!


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## JAX (Jun 2, 2006)

WELL......it works ! ..

I will take some pics before I pack it up. I wanted to do all 6 but just had time to do the bad pair. 

I am selling it now and will give new owner 2 more pair in case they want to get out the solder iron


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## Therum (Apr 18, 2009)

Jax selling an amp. Who would have guessed. LOL Good Job BTW


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## JAX (Jun 2, 2006)

Therum said:


> Jax selling an amp. Who would have guessed. LOL Good Job BTW


well that was the intent soon as I got offer to buy a adcom and took it...which is an excellent amp btw


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## freemind (Sep 11, 2008)

Too late.


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