What kind of cable or interconnect to i need to attach an equalizer with TRS connectors to to RCA PRE-outs and Multiple cahnnel inputs on my Onkyo TX-DS898?
Radioshack has some passable gold RCA to 1/4" adapters, couple bucks each, and use one of your existing RCA ICs. Otherwise, you can buy a cable at places like Marktek.com or other broadcast equipmennt places that adapts. Or you can make one.
TRS is a balanced connection, so essentially you end up connecting the same lead (ground ) from the RCA to both R and S (ring and sleeve). Center pin of RCA connects to T (tip) of the 1/4" connector.