Contour option on Rotel RC-1070 preamp

Unpacked and hooked up my RC-1070 & RB-1070 amp. When I first engaged the contour selector (used instead of bass/treble controlls) I firts got a 'pop'
noise frome ach of the selections; L1, L2, H1, LH. Is this normal for the first time usage. Plus I can not hear a very noticable audible difference in the selections. Anyone with experience with this preamp please set my mind at ease. Thanks in advance.

Also, for the 12V trigger connection does/should a wire come with the amp or preamp or does it need to be purchased seperately?
I use to have this preamp. I recall trying the contour only once or twice, noticed some, but not a great amount of difference. I always left it in flat position when playing though. Someone else may be a more credible source on your question about the contour though. As for the trigger, mine didn't come with cable.
With the pre-amp *on and the power-amp *off cycle through that contour selection couple dozen times and turn on the power-amp and see if it's changed anything.
From the following on your 12v triggers....

[To use the 12 volt triggers on the RA 1070 requires a 3.5mm Mono to Mono cable, which is not included with the unit but can be purchased from any local electronics supply store, such as Radio Shack. The 12V trigger current output of the RA 1070 is 15mA. Some other manufacturerÂ’s components do require more current than this to use their triggers, however. In such cases, using a Xantech AC-1 12V Trigger to switched AC outlet may be useful.]
Thanks Bdgregory & Clbeanz for your responses. The 'pop' is no lnger evident - and the contour control does give just a slight bit of audible difference. I went ahead I purchased a trigger cable and all works fine. I am very happy with my equipment so far.