Connecting a headphone amp to a Monitor Audio A100 amp

[Terry Dactyl]

Hi all,

 

I've just acquired a Musical Fidelity MX headphone amp on approval, and I want to connect it to my Monitor Audio A100 amp.

 

Firstly the system:

 

Music stored on a laptop, controlled by iTunes and streamed via my wireless hub into the Monitor Audio A100 amp via Apple Airplay.

Amp drives a pair of B&W 682 floorstanders.

 

The A100 doesn't have a headphone output. I've connected the M-F MX to the A100 via RCA from the pre-out RCAs on the back of the A100 to the RCAs on the MX.

 

The problem? If I turn the volume down to the speakers, the volume to the MX drops too. I thought RCA pre-outs were independent of the volume control on an amp.

 

Has anyone else tried this setup?

 

Thanks, Terry