Tube pre-amp pop

I would say that when you switch modes on the 16 always mute it or you will get a pop that is normal, I installed a new 16 in my dads system a couple weeks ago and it needs to be muted prior to mode switch and power off, I believe mute is auto on power on.

It's the dealer you should ask for exchange, not the ARC.

Does the pop sound quieter when the preamp is warmed up?

This is the deal. source on first, then SP16 on second ( it takes a minute or two and goes to mute by itself), then I power on the amp ( little buzz at amp then red relay lights then blue lights ). I then use the mute off ( boop noise) , volume up( pop noise ). Put back to mute ( some times "boop", sometimes quiet ). Unmute ( Boop). Not the regular "pop" or "tack" of switching device as in Krell 400xi. It not loud but not a regular pop either. Audphile1, I don't know if this hobby worth anything at all. I am stressed out and burned a pack of cigarette last night 'till 3:am . Chadnliz, Hello again ! I understand that too but I hate to unmute the SP16 since it Boops louder than out functions. At the dealer, his SP16 was dead quite from the speakers. NOw I am much more worry since I don't know if the SP16 or the amp. Thanks again.

No, Audiophile , It is the same loudness.

I would recommend bringing your preamp to the dealer and check it there in their system.