JL Audio Slash V1 1000/1 Parts Source? Found my noise problem...

So been enjoying my first DSP controlled active 3 way front setup and it's been life changing. Don't think I could ever go back to non-DSP, and certainly not to non-damping treated doors. That made a hoooog difference. But, I am still not enjoying anything below 60hz because I have not been able to run my sub. Anytime I would hook the left input RCA into the 1000/1 I'd get horrible noise and screeching. Right channel appears to be fine. I had checked my grounds and tried other RCA cable sets, no change. Now, I never thought anything of it but did notice it was significantly stiffer plugging in an RCA into the left channel. Well, took the time today to find out why. Survey says...

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That doesn't look right. I knew this amp had been opened up before as all the fasteners are different than OE JL (I'm ordering some proper hardware if I can find some) so this prompted me to open 'er up.

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Yeah, that's not good. If that's not a smoking gun... I'm not sure what is. Guess when you insert an RCA it dead shorts and causes the noise/interference. So I proceeded to cut out the cancer. Originally I tried to do it without disassembling the amp. Yeah, burned one of the pots attempting that... so off the end caps, fins, and cover came. Then removed the daughter board. Much easier.

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Anyone know a source for these tiffany RCAs? Or do I have to retrofit something? Would I utilize that contact cage that was removed for the ground if I were to do that? I'm not sure what the person was doing who was in there before me, but there was booger soldering on the left input so guessing it was a botched "repair." Serial number on the backplate doesn't match the interior sticker either. :hmm: Thanks for the input all, as always. Couple of gratuitous gut shots below because why not.

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I don't have a part number to give you BUT...
...first off - what is that film over it all? If conductive - yeah, that could be the problem.
Anyway-

The twist isn't really an issue. That happens when people spin the RCA rather than twist it back and forth as they pull it out. Electrically it really causes no issue.

I say that because one option to avoid replacing it is to fix it. You might not even need to de-solder it. Use a small needle-nose, straighten it out, make sure there isn't any residue (or anything) bridging from that center contact to the ground, and you could be back at 100%!

That said, if you really want to replace it - anyone from Parts Express to Mouser to Digikey or maybe even Amazon for a couple more bucks you could probably find a near-identical replacement for it. Include "through hole" in your search.

That fix will only be harder because you will need to remove the board entirely, you'll need to use desoldering wick to soak out the solder until it comes out, and then solder the new one in. You'll want to use a proper solder station, and more importantly, proper soldering technique to flow the solder. If you aren't confident in this, I'd try to straighten out and clean that existing RCA.

Even if you are a confident soldering technician, I'd start there anyway. I always start with the "lightest footprints" approach first.

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Oh I see you already got it out.

Those parts suppliers will ALL have dimensions, so you can measure the pin spacing, the RCA protrusion from those points, the hole diameter, etc.

Might take some time, but you'll probably find a replacement (including shipping) for all of $10.

But you still might save that one. Clean it up and don't just solder it back - physically check it, physically plug a cable into it and unplug it and observe, and of course measure continuity from pin to ground to make sure it's truly fixed (should be open - no continuity of course). There's no real tech here, and you know that one you have fits for sure.

Might be a little tricky to find, but I like Geolemon's advice.

Thanks geolemon. The only thing that concerns me about reinstalling the jack is that the plastic isolator has been damaged. This allows the inner contact to move around and short. I had thoughts of heading the jack and melting the plastic back into shape... but not sure if that's worth it with the cost of a replacement jack. I'm starting to find options with the "through hole" search term suggestion. Unfortunatley a lot of the replacement options are gold plated... which my OCD will not tolerate. :)

Actually, looking over those pictures again in search of the "film" you referenced (not sure), I noticed the solder goober hanging down by the twisted (+) pin as it comes through the "ground cage." I bet that is what is shorting. I'm going to try and remove that solder blob, reinstall, and see how it goes. Your post above indicates the inside terminal is normally able to rotate (don't think I ever rotated RCAs, but will definitely not do it going forward).

Thanks again, will update with how it goes. Oh, side question, for the thermal paste... is that special for amplifiers or can I use CPU heatsink thermal paste?

Just to clarify-
I'm not saying it's designed to rotate, or even should - but if someone twisted the RCA rather than rotating it back and forth, it could become twisted, like we see. That's not necessarily a problem, technically. Meaning, as long as there's no short to ground, and as long as it's not twisted so much that it's ripped the metal, it should be electrically fine.

That plastic insert is a concern, because that is supposed to be there, that's usually tight enough on the center pin to prevent rotation, but it's not like there's any real bold, no pins, no holes, nothing to really prevent rotation. However, it is certainly an insulator, and you want that to be there. If it's damaged then sure, I'd be leaning more towards the "replace" side of things. In that case, you still could get creative, maybe find plastic washers or rubber O-rings that are the right ID and OD to fit in there, or custom drill some out to fit, but that's more of a pain. But looking at the pic from the outside, it almost appears as though it got pushed out of the RCA connector - again, it's not really attached other than pressure so you likely can slide it back in with a medium amount of force.
But also, on a positive note, it looks like that jack separated, the ground came disconnected from the barrel, and they tried to solder them together but didn't know what they were doing, made a cold solder joint - which really is not much of a solder joint at all. So it looks like there's a big opportunity to fix that ground soldering job and really reattach it properly, with good continuity AND structural integrity at that joint - like always, you have to flow the solder into the heat - then it'll be a good joint. Seems fixable.

That film I was referring to - I was looking originally on my phone and I guess it wasn't clear in miniature. I see now that it's some sort of solder blob above the RCA that should be removed for sure just to be safe, and also I was looking below the RCA beneath and behind the pins and saw a line of something that looked like it was all connected but I see now it's not - but that extra solder(?) behind the pins also should be cleaned up to be safe - in both cases, if for no other reason than they might break loose and make contact and short across the pins. Seems like that cold solder joint, and that's bad news - and if you have a bad joint/cold joint on that ground - sure, that could make noise.

It does look like someone did something in here, based on that - neither the solder at the top or behind those pins seems clean enough for a JL factory job - or even a cheap chinese job. Someone did something there, for sure. I'm still leaning towards "you can still likely clean that RCA connector up to be reinstalled" - but what if the original person inside this amp made a mess of it because they were troubleshooting what appeared to THEM also to be an RCA jack issue? What if it's actually an issue in the preamp stage of the amp, and not really the connector at all? Possibly the person who was in here mangled the RCA connector while "trying stuff", or maybe the original owner did twist too much and did cause a short, and maybe that damaged something in the preamp stage just downstream of the connector? If so, you could solder in a brand new connector and not have a good response.

In the short term, one thing you could do to make sure that isn't an issue, is to temporarily solder that shield portion of the jack in place (to fill the three spots - that's "ground"), then take a piece of speaker wire and solder the negative to that ground, the positive wire into the center hole (where the pin solders), then solder on a cheap $0.99 RCA plug. Make sure it works. Make sure the amp board itself isn't damaged, by temporarily plugging into that RCA and confirming it's worth finding a real replacement jack. The only downside to this would be you'd need to remove it again before fixing it for real - but then you know it's WORTH fixing, plus then if you do install your repaired jack and the noise comes back, then you know it's the jack.

It's fixed! Which is good, because the wife made it abundantly clear I would not be buying another amp to replace it in the near future.

Thanks Geolemon for the advice. I liked the idea of testing the preamp before repairing the RCA terminal but at the end of the day I figured it would need to go in for professional repair if that were the case anyway... so I skipped ahead. I could not find a suitable RCA terminal to replace this one so had to repair. Below I'll give more detail than anyone will probably care about... but I have some time on my hands so here we go.

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First steps above were to extract the terminal + signal center barrel. The heat gun and some needle nose made quick work of that. Then I had to use drill bits to extract the plastic that usually holds the center barrel in place inside the terminal. The way these are made, as it seems to me, is that the + signal center barrel is melted into the plastic that keeps it centered inside the RCA jack. The center barrels have "teeth" or "grabbers" that get formed into the plastic which holds it in place. That assembly is then inserted into the jack and the front of the jack is rolled inwards to clamp the plastic in place. There is a step to the RCA jack (you can see it in the second picture) that provides a stop to the assembly when inserted and clamped. The clamping prevents the plastic inside from twisting/rolling in the jack when an RCA is inserted or removed. The problem jack on this amp had broken free of that clamping and was allowing the inner assembly to rotate. That then shorted the center + on the blob of solder that the original "repairman" had placed to hold the ground barrel in place on the cage that gets soldered to the board. He had done a rather sloppy job of that, but it should have been functional had the inner signal barrel not been allowed to turn/rotate.

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The next step was to find a suitable replacement for the center plastic that holds the center + barrel in place. Not wanting to make a mold and pour my own, because time and effort involved were way too high an investment to make, I grabbed my Harbor Freight kit of O-rings. Found a suitably sized O-ring and determined 4 of the #4 rings in the kit were almost perfect approximations for the inner/outer diameter and the depth required. Almost too good to be true really.

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Next I needed to lock the assembly in place inside the outer barrel of the jack, as it was supposed to be originally. I mixed up some potting epoxy and let it sit for 10 minutes so it wouldn't run so easily when inserted into the barrel. I removed the o-ring/inner contact assembly and coated the inner barrel before the step with the epoxy. Then, inserted the assembly into the barrel and put some additional epoxy in the back to support the center pin and prevent any possibly future shorting/touching of the outer jacket of the RCA.

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Next, went and installed the cured RCA jack onto the board after curing for 24 hours. I know the solder job looks a bit dodgy but those pads are so large I could not get solder to stay in place. It kept running down through the circuit board. So I got it as good as I could up top and made sure the solder job underneath was better in terms of full coverage. Which I was able to do, and it all tested out great with an RCA plugged into the jack when using a multimeter. You can see I also had to "mount" the RCA jack to the ground cage by using solder as the original guy did. That's because these jacks are originally held to the cage by use of some folded metal over the cage. My jack had none of that and so required a solder mount. Hopefully it's a little cleaner job than the first guy left...

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Lastly, I reassembled the amp. Put some new heat sink paste on. Ordered some new white silicon paste instead of using my computer paste as the silicon stuff seems to last basically forever. And I don't see computer thermal paste making a big temperature difference anyway. Reinstalled the amplifier and crossed my fingers. No more interference screeching and noise. Success! Victory is mine! Externally, except for losing a tiny piece of the rolled end on the jack, you can't even tell there was a repair. The O-ring does an amazing job of approximating the black inner plastic visually. :proud:

That looks great from the outside, and simply "repaired" on the inside.

A cold solider joint is always bad news, and you can see the difference between your repair and the prior one - your solder looks like solder does after it flows. Yeah, you have some excess solder, but it's just a little blob and it's not hurting a thing. It's a mile away from the center pin conductor, and it looks like evidence that enough heat was used to flow the solder, rather than just melt it hoping to stick stuff together like the first poorly done repair.

Great work getting creative on replacing that center pin insulator. It really does look great, and sounds like it works just as well as the original one did before it got messed up!

That's some work to be proud of!

I would be pointing out how much money you saved to your wife every day for the next month at least. Every time the mention of money appears on TV, finance section of the news, friends mention an expense... "Hey honey, I literally saved us almost a thousand dollars this month! You got the dishes tonight, right?" [emoji38]

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Thanks again. I used a 60w iron so was pretty sure I could get enough heat into it the parts. I've learned my lesson with 25w irons in the past. Not sure what the guy before me was doing, but you're right, looks like cold solder joints now that I compare.

I'll be sure to mention it to the wife... right after I grab my pillow and blanket from the room. :nuts: Though, I am definitely pretty pleased with the way it turned out. Those o-rings do an amazing job or replicating the outer rounded look of the original plastic insulator. And after I've finished patting myself on the back I can get back to finishing the sub enclosure now that I have a functioning monoblock for the sub. :woohoo: