Expensive cables/connector and solder

Well part of the equation is length. the solder joint is small. Tiny in relation to the whole length.
True it affects the signal, but not nearly as much as the total length of wire.
And there ARE special solders, Like Silver solder, Wondersolder, and Cardas.. Which have special formulations to make a better sounding solder joint

My solder of preference is currently WBT 0800 Silver solder - it's 4% silver content.

I know of others, but Ive used this extensively and on solid silver cables and it has yet to let me down.

Minimal impact (if any) on the sound.

Connectors (RCA, XLR, DIN, BANANAS rtc...) are a whole different ball game - ya gotta get good ones

I'm currently using Eichman Silver Bullet RCA's and Neutric silver plated DIN connectors on solid silver wires - amazing details and huge image space.

:-)

Thank you for your responses! I still think that the solder acts as a "bottleneck" as current flows throught the cable, i.e. the copper cables have a conductivity of a 100 and the solder of the order of 40 depending on its composition. In other words the solder has a much greater resistence to the current flow than the copper. Am I mistaken?? Therefore I think that by having a expensive/exotic cable is a waste of money since ultimately the solder resistance is the one that determines the "quality" of the current transfer to the device being feed. Any more comments?

You are not incorrect, but Elizabeth is correct - the amount is extremely small compared to the cable length and depends more on the connector than the solder

Take a look at this link
http://www.avoutlet.com/images/product/additional/f/iacs_of_metals_n_solder.pdf

It covers metals and solders

The correct practice is to establish a solid mechanical connection before applying solder. In this way the wire is in direct contact with the connector's metal and the solder is used to ensure the connection remains intact. Signal isn't affected if this is done properly.