I do not have any of these dacs and was just wondering what they did as far as heat swing from a cold start to running hot . also how long it takes to get to a full blossom sound , longevity of parts ? heat kills electronics but class A sound the best. I do not want to leave it on 24/7 so I was just looking for maybe an option in these r2r dacs as there is no details I see in the audio gd and the denafrips sites as I thought maybe the owners would chime in. thanks for the replies