Good compatible carts for RS Labs A-1 tonearm?

It is an interesting observation that mm carts "tend" to be threadless and mc carts the opposite.... wonder why that is..

I never had a problem mounting threaded carts on my RS-1A. I used a Te Kaitora and a Shelter 901. As long as you can put the screw up from the bottom of the cart, it will work. This rules out wooden Grados and Kontrapunkt/Jubilee, for example, with mounting holes that don't go all the way through the cart body.

You can use threaded carts with the A1 arm, but the level of 'tightness' of cart body to head shell will be determined by how tightly you can hold the cart to the shell while turning the screw through the two threaded holes. i.e., as soon as the screw head 'bottoms out', that's as tight as you can go.

The alternative is to drill out the threaded cart holes which has the effect of turning the headshell threads into nuts.

Thank you for your responses. I really wanted to try a Grado, but that won't work. I'm going to use some of your suggestions and try a Clearaudio Aurum and a Denon 160 and see what happens.

Regards,

Michael