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Post by ssstonelover on Dec 30, 2023 16:53:57 GMT -5
Star-point grounding is/was a big buzz word starting with the first time I clicked onto the original Guitarnutz site, and I still make my own version of it using terminal rings. I use it on various builds when lots of grounds are involved and I don't want to risk cooking the volume pot. In my version, one of the terminal rings is seated through the volume pot shaft to complete the ground to the pickup/cavity (Faraday) shield, the other is above the pot and angled to it (so the assembly can slip in or off the shaft). I really like having the 'attach point' above the pot for easy access. I find this is a real advantage compared to the low-mount 'store bought' versions available through this company for example solder washer link which give you limited access, a real PITA, in a crowded cavity. Any Lowes (or other good hardware store) has terminal rings in a variety of sizes, and bare copper wire. Might as well make yourself 2-3 at a time, as set up takes more time (as in collecting materials) versus making some in a batch -- and as you might really like having some handy for the next project as well. The illustration shows the major points (and incidentally recycles a previous drawing I made/posted here in 2021) LOL, but with an edit, per the sharp eyes of bluesman13  |
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Post by mikecg on Dec 30, 2023 17:56:32 GMT -5
Neat - and good for 200 Amps - at least!
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Post by sumgai on Dec 30, 2023 20:16:43 GMT -5
Bethany,
Not a bad idea, but I do have to point out one thing: If this washer/ring is the only point of contact between the signal grounds and the Faraday cage, then all is well. For the rest of you reading this...
The whole point of the washer or ring is to isolate the signal grounds from the noise shielding (what is properly called a Faraday cage) for as long as possible. Of course, in order to get out of the guitar at the output jack, there will be a connection between the two. Best practice dictates that so long as there is only one point of contact, then we've done the best job possible.
What are the downfalls of multiple connections between the two segments? Not a lot, but then again, every so often a guitarist will find him/herself in a very noisy environment. That's when we come to appreciate the finer details of Best Practices like this. But yeah, probably most of the time, it won't make any noticeable difference in what comes out of your speaker(s) - good tone, or buzz/hum/squealing/radio stations/etc.
Or as ChrisK might've said: "Why do it wrong the first time when you could just as easily do it correctly when everything's all opened up. Or do you really enjoy doing it a second time, upon finding out the hard way that your laziness just cost you another trip to the workbench?"
HTH
sumgai
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Post by reTrEaD on Dec 31, 2023 13:59:51 GMT -5
My only disappointment is that I'm not able to apply three likes to this post.
I use a high temperature heating element with an extra large chisel point tip when soldering to the back of pots and I've never cooked a pot. But I reckon I'll still use something like this for new work. Simple, cheap, effective, and convenient. Can't ask for more than that.
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Post by stevewf on Jan 1, 2024 0:48:50 GMT -5
I like it. What's not to like?
Only I've always had this question:
How do I get multiple solder joints onto that ring? In the example, there are nine wires joined to that ring. I feel like when I try to join the 3rd or 4th one (let alone the 9th), one or more of the previous solder joints will melt and the wire(s) will fall off of the ring.
Can we have photographs of how people have accomplished this?
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Post by stevewf on Jan 1, 2024 0:52:35 GMT -5
What are the downfalls of multiple connections between the two segments? And on this one, I've had a long-standing question as well: What's the difference between multiple segment connections versus a continuous Faraday cage (like copper foil lining or conductive paint, or mesh, etc)? Aren't there infinite multiple connections in such a cage? |
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Post by reTrEaD on Jan 1, 2024 2:03:41 GMT -5
Only I've always had this question:How do I get multiple solder joints onto that ring? In the example, there are nine wires joined to that ring. I feel like when I try to join the 3rd or 4th one (let alone the 9th), one or more of the previous solder joints will melt and the wire(s) will fall off of the ring. Can we have photographs of how people have accomplished this? Perhaps someone else will provide a pic. Let me try to explain with words. To attach a wire to the ring, bend the wire upward at a 90 degree angle, leaving a length approximately equal to the distance between the OD and ID of the ring. Lay the wire against the underside of the ring, then bend back the portion of the wire pointed up, so that it makes contact with the top of the ring. Then squeeze it with your long-nose pliers. Then solder the connection. By making a strong mechanical connection between the wire and the ring, it will remain in place even if the solder becomes molten when you are making other joints to the ring. |
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bluesman13
Meter Reader 1st Class
Posts: 92 
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Post by bluesman13 on Jan 1, 2024 14:45:52 GMT -5
I thought I remembered from the original star-point ground instructions, that it wasn't necessary to ground each pot to each other as shown on the diagram? There was some discussion about created a ground loop?
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Post by sumgai on Jan 1, 2024 15:31:24 GMT -5
I thought I remembered from the original star-point ground instructions, that it wasn't necessary to ground each pot to each other as shown on the diagram? There was some discussion about created a ground loop? Ground loops are not a 'thing' in ultra-low power circuits like we find in our guitars. The amount of resistance needed to introduce potential trouble spots is in the 10's or even 100's of Ohms, and we don't see that here. As much to the point, John Atchley's original GuitarNuts site espoused using just one connection between shield and signal for purposes of isolation between the user and the amp. But some contributors did note that this also reduces the chance of stray noise sources getting into the signal chain. As to segments, I wasn't speaking to multiple pieces of shielding, I just assumed that we are calling the shielding one segment that needs to be grounded at some point. The other segment is the signal return (or ground, if you must), that's where I get the two segments that need to be joined. In point of fact, ssstonelover's method is excellent. My only 'warning' is that it should be done on only one pot, not on more than one pot (or switch, what have you). It's not easy to spot, but in some cases, it's possible that a break exists between connections somewhere back up the line, and that might cause some kind of noticeable noise at the output. I can't guarantee that it 'will' cause noise, just that most of us have seen it happen at some point in our careers. It might not have happened to us personally, but if you've seen a guitarist on stage having a fit because of a small amount of noise out of her/his amp... that's a sign that something wasn't done with Best Practices in mind. reTrEaD correctly describes how to secure a wire to a contact point. Solder is meant to make a good mechanical connection an even stronger mechanical connection. At the power levels seen in the guitar, it should be possible to not use solder at all, trusting to strong mechanical connections to not come apart. But alas, that trust would be misplaced, for we've all seen, and perhaps personally experienced, wires coming loose faster than a speeding bullet. My method is to wrap all of the wires around the ring/connecting point first, and then solder everything all at the same time. There've been times when that wasn't possible, but about 98% of the time, it beats worrying about some previous connection coming loose, and having to re-do the thing. HTH sumgai |
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Post by ssstonelover on Jan 1, 2024 15:33:09 GMT -5
Only I've always had this question:How do I get multiple solder joints onto that ring? In the example, there are nine wires joined to that ring. I feel like when I try to join the 3rd or 4th one (let alone the 9th), one or more of the previous solder joints will melt and the wire(s) will fall off of the ring. Can we have photographs of how people have accomplished this? I've done some of these. The attached photos are with my old soldering equipment (I've got lazier about documenting all the soldering nowadays, sorry!). The current setup includes T12 tips, Kseger solder rig with accurate temperature settings and correction, and thus can do a cleaner job. A deft touch is required whether you solder to a ring -- or to the back of a pot -- and some pre-tinning of the wire and the ring is going to help too, as are reTrEaD's and Sumgai's suggestions Ring Solder Considerations: -- I like that the ring gives a lot of possible solder positions 360 degrees around the circle -- I like that it heats and cools quickly (compared to a pot back) Both these factors give some help in avoiding the melting of previous connections (when using a quick deft touch, good iron, pre-tinning) -The image at 12:00 shows one layout for re-accessing wires (should it ever be necessary) and avoiding melting of already made connections, by bunching 'like' wires together in different groups. -The image at 7:30 shows a more stretched out way to attach the wires, BUT the ideal way is more spread out evenly over the circumference in terms of avoiding melting other connections. -The image at 4:30 shows all connections bunched, and is the poorest one for later access and/or avoiding accidental melting of connections that don't need rework. I'm sure I've exceeded 6 connections on some of my builds, but this should give some examples of how to work with this idea, and what to watch for.  |
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Post by stevewf on Jan 2, 2024 2:55:33 GMT -5
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Post by ssstonelover on Jan 2, 2024 4:45:12 GMT -5
Steve, you've got a handle on it, and yes, that is the right link to a product I tried but liked far less than my home-brew solution. Someone elsewhere made a comment about using aluminum terminal rings with copper wire, to the effect that one should worry (over time) about galvanic reaction and consequent loss of conductivity, particularly if the rings are merely crimped to the wire. Personally I crimp and solder, and use solder flux as well, so I think I'm good, but then again humidity and environment is much controlled on a guitar than say on a terminal strip shared between a car and trailer hitch subject to road spray, dew point, salt corrosion, etc.) Having said that, the ideal setup would be (in theory anyway) to use copper for the wire and the terminal rings, and for the pickguard shield and cavity shield as well (not that I personally have experienced any issue with AL pickguard shields even over 10 years or more, and their interaction to copper foil in the control cavity or elsewhere). Maybe someone with strong 'bimetallic corrosion' knowledge can weigh in on this. I am always open for more education. Anyway, if you were to go for copper terminal rings, they do exist and look tempting. Copper terminal ringAnother thing to note is most terminal rings are designed for thick (like 8G) wires (at least those what would work with a pot shaft). I like to use something thinner (example 14G) for the bare copper wire between the 2 rings (not that there is anything wrong with fat solid wire). In that case, using my handy Dremel and a rotary cut-off wheel, I re-slit the attach point so it can be squeezed/crimped/soldered to a smaller diameter to snug up the solid strand copper wire. |
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Post by reTrEaD on Jan 2, 2024 13:07:30 GMT -5
Someone elsewhere made a comment about using aluminum terminal rings with copper wire, to the effect that one should worry (over time) about galvanic reaction and consequent loss of conductivity, particularly if the rings are merely crimped to the wire. Personally I crimp and solder, and use solder flux as well, so I think I'm good, but then again humidity and environment is much controlled on a guitar than say on a terminal strip shared between a car and trailer hitch subject to road spray, dew point, salt corrosion, etc.) The ring terminals some people assume are aluminum, may be a different alloy. If they actually are aluminum, they are probably plated with something else. The solder alloys typically used for electrical work won't bond easily with aluminum. Aluminum forms an oxide when exposed to air and that process is accelerated when aluminum is heated. Special flux and a solder with a generous amount of zinc is typically used. If you can solder to the ring with common solder, I wouldn't be concerned about galvanic action. JMO. |
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Post by stevewf on Jan 2, 2024 13:58:22 GMT -5
Solder is meant to make a good mechanical connection an even stronger mechanical connection. HTH It does indeed help, and it'll be considered in every solder joint I make from now on! Just this: if I foresee a need to remove the wires from the lugs later, sometimes the particular situation makes it difficult to use a solder remover (suction or capillary), which makes the removal job... unpleasant. Then it's tempting to use only the solder as the mechanical connection. Like one a five-way blade, I've laid a bare copper wire across three sequential lugs, just lying on top of them, and the solder holds it in place. Removing that wire later is easy. Contrasting that to curling the wires around/though each of the lugs (or even just the lugs at the end of the wire), the undoing seems more difficult; by the time I grip the wire with my needle-nosed pliers to do the unbending, the solder has cooled. I don't wanna derail the thread because the original post seems like a good idea. But if anyone has any tips for my soldering, I'd love to hear, even in another thread. |
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Post by ssstonelover on Jan 2, 2024 15:06:58 GMT -5
The ring terminals some people assume are aluminum, may be a different alloy. If they actually are aluminum, they are probably plated with something else. The solder alloys typically used for electrical work won't bond easily with aluminum. Aluminum forms an oxide when exposed to air and that process is accelerated when aluminum is heated. Special flux and a solder with a generous amount of zinc is typically used. If you can solder to the ring with common solder, I wouldn't be concerned about galvanic action. JMO. Upon reflection and more investigation terminal rings seem mostly to be made of copper (or brass) and tinned (accounting for the common silverish color). The warning about 'aluminum' (that I found elsewhere) seems to be alarmist and very unwarranted and thus a misplaced worry, based on my actual experience and actual online data. Additionally terminals (by and large) are meant to be compatible with soldering, and in practice I've never had an issue with solder sticking when standard electrical solder flux is used. If there was ever a concern, scratching a ring surface with a sharp object, would show brass or copper below the tinned layer, and is an easy test to perform. The secondary consequence of this material review is that galvanic action will not exist then either. Sorry, for any concern I forwarded earlier, i should have investigated it at that point instead of passing what amounts to rumor or assumption (however good-intentioned that source was). Oh well, we know how the internet is (good and bad), and yet another reminder for the reason for supporting this forum, which a source of reason, empirical knowledge, help, and experience. |
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Post by reTrEaD on Jan 4, 2024 10:55:44 GMT -5
Sorry, for any concern I forwarded earlier, i should have investigated it at that point instead of passing what amounts to rumor or assumption (however good-intentioned that source was). Oh well, we know how the internet is (good and bad), and yet another reminder for the reason for supporting this forum, which a source of reason, empirical knowledge, help, and experience. No worries. Conversation is good. |
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Post by sumgai on Jan 4, 2024 12:17:43 GMT -5
Sorry, for any concern I forwarded earlier, i should have investigated it at that point instead of passing what amounts to rumor or assumption (however good-intentioned that source was). Oh well, we know how the internet is (good and bad), and yet another reminder for the reason for supporting this forum, which a source of reason, empirical knowledge, help, and experience. No worries. Conversation is good. And informative conversation is even better.  |
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Post by ssstonelover on Jan 5, 2024 18:57:52 GMT -5
I thought I remembered from the original star-point ground instructions, that it wasn't necessary to ground each pot to each other as shown on the diagram? There was some discussion about created a ground loop? You are absolutely correct, the example drawing (tone pots) is a bit sloppy in that regard. In a perfect world the caps would ground on the 'star point'. The annoying part is the drawings are done on my other (old) computer, so sorry for the delay. I'll replace it now. |
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