I have a P.H. Hobbies steam sound board V2-6 that was added to a tender, not original to tender. It has decent sound like hissing, bell clanging, whistle, and chuff chuff. The problem I have is when it first starts out there is a annoying, lets call it squelching sound. It will go away after the tender gets rolling about 5-10 seconds, and then the sound is ok. It does this every time the tender starts to roll. There is a volume control but turning it down does not get rid of it, only if the volume is turned all the way down. Thanks for any info.