Power Amp: Audio Research D125 Tube Amp
Pre Amp: Audio Research LS-15 Tube Amp
Speaker Cable: Purist
Interconnector: Transparent Music Plus

My Problem: When I power on my amp, there's no sound, just a increasing humming noise. Additionally, when we change the power amp, to a different amp; everything is fine.
Please let me know what's wrong with my set-up [amp] problem.

Thanks!

Sorry, if I'm not allowed to post this here. I need the help! Thanks again.