WBT Banana Connectors

Those z plugs are what I call BFA.  I'm just going by what I've seen them called.

I have a set of those KLEI bananas.
They are very very nice. Much nicer than about anything else.

but...

They have serious issues with coming loose if you have heavy cables.

They are pure copper, which is probably the worst possible choice one could make for a spring. You can tighten them up by inserting another banana inside them.

If you insert them at even the smallest angle, they will compress, and since they are copper, they will not spring back fully. My cables are fairly stiff and the leads are fairly short, which meant that both bananas had to be inserted square at the same time - which was awkward.

The outputs on my Manley Snappers angle up at 45 degrees, and the weight of the cables would compress the bananas and cause them to become loose unless I wire tied the cables to the legs of the amp stands.

The manual for my Snappers was very clear - never disconnect the speakers while the amp is one or you might have to buy a very expensive output transformer.
I replaced them with spades.

They are really awesome bananas, but the issues I had made them not worth the risk.

Thanks @carlsbad and @mbolek . Those look interesting too!

@joshua43214 this is exactly why I've been going down this rabbit hole. I'm worried about the weight and stiffness of the cables too, and also managing what to do on the back of the Marantz with the small spring connections. Was thinking banana but I'm not changing out frequently, maybe I'll give spades another look. Fun to learn, thank you again everyone for all the good leads.

Hi jtg_ts!   Go silver if you can afford it. Some other brand might be cheaper. Test (with a magnet) all the connectors in the speaker path (amp and speaker box connectors and be sure they are not magnetic (contain iron). I just switched out some connectors on an amp with all copper ones and there is a definite difference (improvement). You've got pretty good cables now. Be sure other connectors aren't  preventing you from hearing how good they are. Happy Listening!

This thread is bringing out the technical challenges  of banana connectors.  Traditional bananas are often gold plated steel (yes steel) as springs are needed to make them expand in the "banana" section.

Solid silver and copper (such as ofc) are very soft.  KLEI is one of my favorite connector manufacturers.  they make low mass, high conductivity connectors.  but solid copper won't be strong enough with a heavy cable.  

I like the tellurium copper with heavy silver plating (tellurium alloy copper is not quite as conductive but much stronger than pure copper).

Jerry