How do I connect a separate CD transport

Yes if the CD player has an output that is compatible with the input on the DAC/CD player you want to interface with.

You could if you could find a tech that could add a digital INPUT to your unit. It might cost more than it's worth, but I'm pretty sure it could be done.

I can't recall anyone ever mentioning that they had a digital input added to a CD player that didn't come with one from the factory. I'm not saying it's impossible, but I would think that some people would have spoken about having done it if it were practicable. Now that I think of it, Musical Fidelity put out a bunch of expensive CD players with bad, irreplaceable transports and they had to be thrown away when they failed, as I recall.

Why not just replace the transport in the CD3? If I am not mistaken it uses a Philips CDM Pro2, the same transport that a lot of CD juke boxes used. Replacements are still available on the internet. It is an excellent sounding transport. My Ref CD7 uses a version of the CDM Pro2.

Sum4jn-
do not chance it, either fix the ARC or sell it. ARC can repair/replace the transport-no problem. How long have you owned the CD3 Mk II? When did you purchase the ARC spinner?
Keep me posted & Happy Listening!

I asked the folks at Resolution Audio if they could add a digital input to my CD-50. They told me it could be done but they weren't enthusiastic about it. My impression was they were busy and just not interested in devoting the time it would take.

As for changing out the transport, if you can find one it a piece of cake.

i second fixing it by ARC

Curious the result of this. Have a cd3mkII, and wonder about servicing costs/how long arc will be able to repair it.