Best solder & technique

A handheld (“small”) ultrasonic welding tool costs tons and tons of shekels.
I’d rather avoid solder because of its poor IACS being a bottleneck, but I can’t.

What’s the best solder for current delivery on the market today and what’s the best way to implement it to attain as close as possible to a metal-metal interface?
Loop the conductor, then apply minimal solder to keep it in place?

I don’t obsess over solder for my projects. I’ve been buying standard 60/40 solder from partsexpress for years with excellent results. I am big on proper lead forming, however. For all through hole parts I crimp a U in the lead so that when I push it through the hole it snaps in place. I’ve gotten adept at using a needle-nose plier to do the lead crimp trick. That also assures some part of the surface of the lead will make contact with the pad (I’m talking about a PCB, btw). Where necessary I’ll tightly wrap a lead on a lug so that I’m certain of direct metal to metal contact. All of these techniques have the added benefit of requiring minimal solder to secure the connection. When working on audio gear one type of connection I loathe is certain types of RCA connectors that force you to tack the center lead into what amounts to little more than a trough. Typically with thick gold plate and a lot of metal that needs to be heated by the iron to get the solder to flow and stick. Curse words have been uttered trying to solder that type of connection.


Whether or not to obsess over technique of weld/solder is a matter of the materials used… If I buy 7N UP-OCC cryomagnetically treated silver wire, I will obsess over how it’s terminated.

(Not that I’ve bought any yet)

Anyone who’s used let’s say Furutech silver-gold alloy solder, have you noticed audible improvement?
I know people have auditoned different solders.

(A hand-held ultrasonic welder costs 18k$… I wonder why big cable manufacturers don’t just ultrasonic weld their terminations since the machines aren’t a cost object to such companies. I wonder how the perfectionist metallurgists at Siltech make terminations…)