It's been a long time since I had a G70 here (and I'm glad they're gone
) but what I remember is the factory settings for each tube were very, very high. Sony set-up the machine to pump out as much light as possible but the tubes do not last very long. If your turning contrast all the way down it's probably because the tubes are set too high. IF you do a search for "Sony G70 Gain" on the forum you'll find some interesting discussion.
Here's a good thread with some numbers from people who had their machine calibrated. Obviously it's different for every machine but it will give you some rough numbers to compare
A forum community dedicated to home theater owners and enthusiasts. Come join the discussion about home audio/video, TVs, projectors, screens, receivers, speakers, projects, DIY’s, product reviews, accessories, classifieds, and more!