Where to connect sleeve of 1/4" Stereo jack?

[aeros88]

I've built a speaker selector box that connects to an amp connected to a turntable with a built in preamp so that I can switch between my bookshelf speakers and a 1/4" TRS jack for a pair of headphones to plug in.

I currently have the Tip and Ring connected to the switch (L+/R+) and the Sleeve connected to the L-/R- of the input. Without that Sleeve to Input negative connection, there is severe static and very low volume. With the connection the volume is good but there is still a fair amount of hiss. The speakers have none. Am I not supposed to connect ground to negative speaker terminal?

 

[Alabalcho]

Where is your selector box connected:
- between the amplifier and speakers / headphones,?
- between preamp and amplifier?

 

[aeros88]

Sorry, I mixed up my previous post. The turntable has a preamp which connects to an amp via RCA cables. The amp outputs via the four speaker wires to my selector box which switches between speakers and headphones (1/4" stereo plug).

The selector box sits between the amplifier and speakers/headphones.