Best RCA female output connector.....a CD player ?

I've used them in my system compared to Vampire, Cardas, radio shack brand, and Tiff.
I'm only referring to female chasis mount because I'm not a big fan of their male plugs.
If you look at the specs, the WBT uses more pure copper than most of the female RCA plugs(99.98%copper center and 68% copper for the ground return.) Their gold plating is also better than most(5 layer). The construction is also stronger than the most(bigger and thicker with good teflon insulation ring.)
Aside from all these fancy descriptions about the specs and physical description, it does give better definition in high and low frequency extension and very clean sound overall.
As I said, I only evaluated in my 4 amps and 4 preamps.
I have not tried other fancy plugs mentioned above by some other folks.
For their topline 201, IMHO, it's as close as to solder directly to the system. It's $38 a pair.

I think the purity does make a difference. I compared the male plugs I found the similar results too.

Definitely agree with Sean. The Op-Amp replacement will make a bigger difference than replacing female RCA mount. If I were you, I wouldn't bother with replacing female RCA mount.
I've replaced my CD player Op-amp and it's really day and night difference. However, it does change the tonal quality too. It will not sound the same as your previous op-amp. It's either you like it or you don't. I've put sockets in place so that I can switch to different op-amps without de-solder and soldering again.
You can search diyaudio on CD player clock mods and op-amps mod.

The idea of connectors in general always makes me think that there has to be a better way to interface cables with their respective components. With the thousands of dollars some consumers are spending on IC's, speaker wires, etc... And the R&D cable manufacturers do with metallurgy, dialectrics, winding geometries and such, it surprises me that there hasn't been more innovation in the seemingly critical joining of wire and component.

You certainly don't see many people using two .5 m pairs of Valhalla joined in the middle with an adaptor to make up a 1 m length, but the RCA's, male and female, at the component ends don't seem to cause much concern.

That said, I am a big fan of the Eichmann Bullet Plugs and pray that they will make a female RCA that is just as innovative and minimalistic as the male. If they build it I will buy.

I have been toying with hardwiring my IC to my CD player just to see if it really does make any difference.

Pilar: For Eichmann to make a female RCA, they would have to make the males and females in such a manner that they would be "keyed" to fit in only one way. Otherwise, it would be hard to make a ground connection due to the limited points of contact on the connectors.

Personally, i think that the Eichmann's are a lot of "hooey" from a technical perspective. While i've not used them personally, they do appear to be relatively brittle and not nearly as robust in construction as i'd like to see. Sean

Sean, I'm surprised that you would summarily dismiss a product you have never used. The Bullet Plugs are the real deal, I've replaced more "robust" (and expensive) plugs and in each case noticed an improvement. For me the robust quality of the bigger RCA's is the problem, do I want 1 oz. of metal terminating my cable or 1/10 oz.?

As for being fragile, I've soldered and resoldered them many times with no ill effects. Heat shrink on the cable ends then another piece over the cable and barrel provides strain relief.

P.S. -I'm just another "internet trained" hobbyist with no formal background in this stuff so take my opinion for what it's worth.