[bjmccoy]

Originally Posted by 2fastdriving

I was sitting here, listening to my new ref5 and ref75, trying to get this break in process moving faster, when I had a thought. It was sounding pretty shrill and thin to me, which I just chalked up to breaking in. But I thought I should check the tube bias, since that is so easy to do. Well guess what...all four kt120's were way low on the bias voltage! I dialed them in, and most of the shrillness is gone, and bass has improved! At least it sure seems that way to me. Anyone have a similar experience with tube bias that was wrong from the factory? Is it just my houses power that might be a volt off or something?

I too had some shrillness to start with; most of it was gone after 50 hours. But came back around 120 hours for 20 to 30 hours. I checked the bias the first week are so, but I did not have to adjust it. I forgot about it until Tom showed up to install my Linn turntable and complete to setup of the speakers. He noted that the amp bias needed to be adjusted (it was at the low end of ok range). That adjustment was made around 300 hours. I checked the bias once a week and have seen little change. As with most things; give it a little time…it's worth the wait….Enjoy

Blaine