Audio Research DS Series Amplifier owners. Turn on "twang" from transformer?

Just got a brand new DS450 and I'm burning it in now. I notice when it relays on, there is a fairly audible twangy electrical sound that comes from it that subsides after a couple of seconds. None of my other amps have had this type of sound after the relay clicks on.  Has anyone else noticed this? I can only notice it if there is nothing playing and the room is silent, if there is music flowing from the preamp before the amp relays on. I can't notice it.  Is this common?


It's common in many amps to some degree of magnitude. Make sure that woofer and other drivers movement is very minimal to invisible. Other than that, if substantial contact tech support.

I have planar speakers, so it's not possible to check drivers.  After two seconds or so, it's practically silent. I'd doesn't appear to be sending sound to the speakers and sounds contained to the transformer. Probably normal.  Just interested if anyone can confirm if there unit does this.  
Almost any toroidal transformer does this on startup, very normal and nothing to worry about.

Good Listening


Thanks for your replies. ARC  confirmed its from the inrush of current and its normal. 
I have a ARC DS450 and it does the same noise and so with my rotel amp and yamaha avr.