To repeat what Nsgarch said - Cardas will make them for you.
I think there were some for sale here last year, but they were very short.
I think there were some for sale here last year, but they were very short.
Balanced Y Adapters--Where to Find
The manual to the Levinson 380S pre specifically discusses the use of Balanced Y Adapters for passive biamplification. I have no clue who makes these or where to buy them. Can someone offer direction?