Circuit elements may be destroyed under the high temperature stress.
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1)Consider the hundreds and in some cases possibly even thousands of solder joints within many electronic components. Why worry about a few more external ones?
2)In a properly soldered joint there will be extensive direct contact between the conductors being mated, so the resistance of the surrounding solder shouldn't matter.
3)The resistance of a properly soldered joint is likely to be negligible compared to the resistance of the wire being soldered, due to the great disparity in length.
4)In many applications, especially line-level analog interconnects, fraction of an ohm resistances will be totally unimportant anyway. Assuming, that is, that the line-level components being connected are not susceptible to ground loop issues as a result of poor design (in which case the resistance of the ground conductor might be of some significance).
I understand that ARC uses "silver solder" in its products. That said, I am dubious the solder is 100% silver or any silver alloy even close to pure silver. Not even sure what the melt point of pure silver is ... but I surmise it's a lot hotter than the typical lead/tin alloy used in regular solder.
Is the notion of so called "silver solder" real or hype??
Silver solder isn't pure silver - it's a mixture of metals with silver in it. The other metals mixed with it for what is called a eutectic mixture - this lowers the temperature of the mix to a point where it all melts.
And the reason silver is touted as better is that it has the lowest resistance among the elements. Whether the hype is true, I don't know.
One reason not to 'weld' parts together is that that would make it harder to remove the parts in case a repair is needed. Plus, like Czarivey pointed out, high temps would destroy everything.
09-25-15: TbgI don't doubt your word if you have experienced that, but it needn't be so. Consider the hundreds of thousands and in many cases millions of solder joints in the avionics systems of military aircraft, which are accomplished mostly by automated soldering processes. Those seem to do ok, despite being exposed to extremes of vibration, temperature, and other environmental factors.
Working with silver solder is nearly impossible. As previous posters mentioned, you connect conducting surfaces and than apply solder that wraps connection TIGHT. With silver rich solder you either have to apply excessive temperatures or your solder won't be able to wrap the connection. Silver solder is only used for marketing. You can also use screw-in wire guards, but those you will have to inspect for corrosion and clean once in a while.
What else can be sacrificed for the good sound? Maybe welding bubbles you can possible face during assembly? Short answer is stick to old school-good school.
Even better yet...forget welding which is so old school to start with, form the entire circuit end to end and with no wires and with no connections to solder. I bet someone somewhere is doing this already to some extent but they have way more money to spend than anyone here. Bigger better integrated circuits per se. Oh wait, point to point wiring sounds better than that already. Oh well, back to the drawing board....
if you are not happy with solder then you could always try conductive epoxy! Drying time might be the only issue :)
For me, silver solder is fine and it seals against oxidization, just ensure that the pieces being soldered have a good connection and try not to use too much solder. Also, using a good flux paste ensures good eutectic flow :)
Almarg, I doubt seriously if the solder you and I have access to is anything like that used in the military.
I spent 20 years as an electronic tech in the USAF and there was nothing special about the solder we used. Yes I was soldering components on boards as well as connectors used in aircraft. Now maybe NASA uses something special, but I doubt it.
A good solder joint is going to last. It just has to be done properly. That's what quality control is for.
Al's first response is excellent, he obviously knows what he's talking about.
It's best for the materials being soldered to already have a good mechanical connection before soldering. The solder just holds it in place.
However, solderless set-screw connections do tend to sound best but the difference vs using good lead-free silver solder like WBT or Johnson is slight. The best RCA plugs imo, WBT 0102, are the best despite requiring soldered connections.
The best connection is probably wire wrap. With wire wrapping. Some audio gear made in the 1960's and 1970's used this approach, but for cost reasons, it is no longer used. The connection is physically very strong and completely gas tight (no oxidation at the physical point of connection). See the following:
The link Larry provided is a good summary of wire wrap technology. With respect to its (non-)applicability to audio, though, in addition to the cost factor I would highlight the following paragraph:
Wire-wrap works well with digital circuits with few discrete components, but is less convenient for analog systems with many discrete resistors, capacitors or other components (such elements can be soldered to a header and plugged into a wire wrap socket). The sockets are an additional cost compared to directly inserting integrated circuits into a printed circuit board, and add size and mass to a system. Multiple strands of wire may introduce cross-talk between circuits, of little consequence for digital circuits but a limitation for analog systems. The interconnected wires can radiate electromagnetic interference and have less predictable impedance than a printed circuit board. Wire-wrap construction cannot provide the ground planes and power distribution planes possible with multilayer printed circuit boards, increasing the possibility of noise.For those reasons it is pretty much inconceivable to me that something like a high resolution DAC, a high gain phono stage, or any number of other examples that could be cited, could be implemented successfully with wirewrap construction. And then there are the high power devices in power amplifiers, that require special mounting, heat-sinking, and heavy gauge connections ....
Surface-mount technology has made the technique much less useful than in previous decades.Regards,