B&K amp popping with receiver pre outs


At my weekend place, I have a Yamaha rx-a3000 receiver which is acting as preamp for some vintage b&k amps. The really early generation b&k's (black with gold lettering) work fine and sound great. But, if I run the next generation, with the red lettering And musical staff on the logo, they all pop when I mute or change sources on the preamp. 2 techs found nothing wrong with the 2nd gen Amps. Any thoughts? I measured no dc offset in the pre outs. All the amps sound good though. Thanks.
tomask6

Showing 3 responses by tomask6

PS the setup is used for home theater setup hence the multiple amps but the popping is heard on all sources.
Skriefal what preamp are you running? The b&k's don't pop with other preamps, but the yamaha is super convenient so i'd like to stick with it.