Construction pet peeves

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Deke609

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on: December 14, 2019, 04:51:44 AM
Solder cups! They make it so difficult to achieve a solid mechanical connection!  Why not a simple solder lug? Or a turret?

I've now taken to treating the solder cups on rca input connectors as quasi-turrets: remove 3/4" of insulation from wire; stick end of bared wire in cup, and then tightly wrap and crimp remaining bared wire around the solder cup post; then solder. This is still tricky because the cutout for the cup often forms a slope on the post that will tend to push the wire wrap up and loose.

Grrr. I do not like these things.




Offline grufti

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Reply #1 on: December 14, 2019, 06:24:49 AM
I've found various ways to make this task easier. Solder paste is one of them. Pre-tin the wire. Apply some solder paste to the solder cup from the syringe that it came in. Stick the wire into the solder paste. Apply heat. Hold tight until set. Done. Alternative strategy: pre-tin the wire. pre-tin the solder cup. Apply a tiny amount of ChipQuik [or other] electronic soldering flux to the solder in the solder cup from the syringe that it came in. Hold the wire on top of the solder in the cup. Apply heat. Hold until set. Done.



Deke609

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Reply #2 on: December 14, 2019, 07:05:27 AM
Those sound like all good ways of dealing with the problem. I used to bend a 90 in the bare wire and rig things so that there was tension pulling the hook against the inside of the cup to get something resembling a mechanical connection, and then solder. 

But why is this even necessary? Why have a solder cup at all??!!! A lug or post would be so much better. Baffles me.

cheers, Derek



Offline Jamier

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Reply #3 on: December 14, 2019, 08:05:32 AM
Derek,
     I usually cut a small notch in the slope of the cup. Then I get some 20 ga. Copper doorbell wire, strip off the insulation, and wrap that around the cup/post where the notch is. This will hold the wire in place while you solder. Then cut off the excess.

Jamie

James Robbins


Offline Paul Birkeland

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Reply #4 on: December 14, 2019, 12:53:00 PM
Solder the cup first, let the solder cool, then heat it back up and stick your wire in.  That's how I do it with the limited number of hands that I have.

Vintage RCA jacks are constructed with a tab and a hole.  The problem is that they are not as physically robust.  There are also some knock off CMC jacks on eBay that have lugs you could wrap a wire around.

Paul "PB" Birkeland

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Deke609

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Reply #5 on: December 14, 2019, 02:25:56 PM
Thanks all. I like Jamie's idea of cutting a notch.  Maybe it doesn't make a difference, but I don't like the idea of my signal wire relying on just tin/lead (with or without a tiny bit of copper and/or silver, depending on thei solder one uses) to make a connection. I'd prefer a tight mechanical connection.  But, again, maybe it doesn't matter.

But my real gripe is that these connectors are manufactured with a solder cup in the first place. What purpose do they serve, that wouldn't be just as well served by a turret or big lug?




Offline Thermioniclife

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Reply #6 on: December 14, 2019, 03:21:16 PM
As PB suggested Tin the tip of your iron and place it on the outside of the solder cup and fill the cup up with solder. then tin the wire that has to be connected. at this point it is very easy to make the connection, just place a tinned iron on the side of the solder cup and when it melts place the tinned end of the wire in the cup perhaps leaving the iron on the outside of the cup foe a couple of secs to melt the tin on the wire and you are done. No muss no fuss. two hands needed only.

Lee R.


Offline 2wo

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Reply #7 on: December 14, 2019, 05:18:03 PM
The ones I use, I just drill a small hole in the cup and treat it like a terminal point.

I have a little hand drill that as perfect for this sort of thing...John

John Scanlon


Deke609

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Reply #8 on: December 15, 2019, 03:14:55 AM
Another fine idea. I'm going to try this one. I think I can Dremel a max of two small holes in the cups - just enough diameter to get a signal wire and/or resistor lead through, as the situation requires.




Offline Jamier

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Reply #9 on: December 15, 2019, 04:33:29 AM
Derek, I have used RCAs that have terminations that aren’t cups. I have some WBTs with perforated connections like a terminal strip. They were rediculously expensive and did nothing to improve the SQ of the amp. As I gain more experience, I have become better at knowing which parts justify larger investments, and which ones that don’t.

Jamie
« Last Edit: December 15, 2019, 04:35:39 AM by Jamier »

James Robbins


Offline Deluk

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Reply #10 on: December 16, 2019, 12:41:04 AM
Forget the drilling and Dremeling, just spend an hour practicing how to do it. As PB says it's about the simplest joint you will do on these kits. Soldering iron, and tweezers if you want to keep your fingers out of the way.



Deke609

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Reply #11 on: December 16, 2019, 03:37:01 AM
Forget the drilling and Dremeling, just spend an hour practicing how to do it. ...

Yeah, I hear you, but my issue isn't that I can't make the connection or find it difficult - I doubt anyone who has posted on this thread has a problem just making the connection. My issue, and I suspect others', is the the difficulty of getting a solid mechanical connection such that the wire and cup are pressed/wrapped tightly together - whether for reasons of joint strength and/or possibly improved signal transfer.

I have some WBTs with perforated connections like a terminal strip. They were rediculously expensive and did nothing to improve the SQ of the amp.

Yeah, I've seen those.  But like you say the prices are insane. As for SQ: I can't imagine them making much if any difference (although I suspect a really poorly made connector could hurt the SQ by not making a good connection).

Tangent: I am a big fan of the WBT locking style of RCA connectors, but b/c of WBT prices now only buy knock-offs (which are never as good mechanically).  About 25 years ago when I got my first "good sounding" system (Arcam Alpha CD/DAC and Arcam Alpha integrated amp, and small Linn speakers), I auditioned three different interconnect cables - one of which was a WBT cable that I ended up buying . The audio store set up the listening room with the components in my system and we swapped the interconnects repeatedly over the course of an hour. The differences were easy to hear - and so I became a believer in cables early on. Although, in retrospect, I think the WBT cable might have been a bit bright sounding - which (for me) creates the immediate impression of increased detail. But, man, would those WBTs ever lock on to the RCA jacks. Talk about a tight connection. There was just something really satisfying about that.  That stereo purchase left me completely broke for a summer - I think i spent my entire grad student summer teaching stipend on it, and was left eating rice and beans until September. Priorities, right?  ;D  I guess in some ways I haven;t changed much in the intervening 25 years!

cheers, Derek
« Last Edit: December 16, 2019, 03:40:33 AM by Deke609 »



Offline Tom-s

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Reply #12 on: December 16, 2019, 08:30:31 AM
My trick is like PB's. Maybe i can add this.
My most used tools when soldering (next to the iron and cutters) are my needle holder or needle drivers.
These come in various sizes and give the advantage to hold an object without applying any force, which helps with more precise handling. This comes in very handy when sticking a wire into a hot/molten solder joint.
In my experience it's a large step up from needle pliers or a tweezer.



Offline Doc B.

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Reply #13 on: December 16, 2019, 09:24:02 AM
We call them forceps in the states. They are indeed handy.

Dan "Doc B." Schmalle
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Bottlehead Corp.