Transformer coupled outputs cannot pass DC. This is fundamental to a transformer of this type. As for the retailer exchanging the amp - be happy you bought a McIntosh. Krell would not do this for me a few years back. I had to send it off and wait for several months. Needless to say, I don't have Krell any more. Arthur
Poping noise starting up Mcintosh MA 6900
When I turn on the amp using the standby button, I get a popping noise that is audible through the speakers. Not loud, but can be heard. The amp is just 1 week old. I had the MA 6500 in the same set-up and liked it so much I upgraded to the 6900. The 6500 made no noise, none. Is this inherent to the design (autoformers) or is there a problem? If anyone has the same experience or has suggestions, please respond, thanks.