Oh and one other surprising realization. Preventive tube changing is a great idea. I’d got about 2000 hours on my set of 6h30s in my Ref 40 but had an increasing sense that there was something a little off in the sound. A bit of tightness perhaps. I was also suffering from odd (once every 3-4 sessions) channel drop outs. ARC say the amp should be good for 4000 hours on a set of tubes
As a new set of cryod tubes from Kevin Deal are not that expansive I decided to go for it - wow wish I’d done this sooner! It’s like a whole new amp. Even at 20 hours in the sound is so much crisper and more open. I’d recommend all owners plan on swapping out every 1000-1500 hours or so, I think you can go longer on the power supply tubes
i half suspect that power up down may be as much an issue as absolute hours. I tend to listen for shorter (1-2 hour) sessions so put the tubes through a lot of on and off cycles. With my Ref 2SE phono I needed to change at 500 hours. Anyway certainly if you listen for shorter times as I do don’t expect to get maximum tube life
As a new set of cryod tubes from Kevin Deal are not that expansive I decided to go for it - wow wish I’d done this sooner! It’s like a whole new amp. Even at 20 hours in the sound is so much crisper and more open. I’d recommend all owners plan on swapping out every 1000-1500 hours or so, I think you can go longer on the power supply tubes
i half suspect that power up down may be as much an issue as absolute hours. I tend to listen for shorter (1-2 hour) sessions so put the tubes through a lot of on and off cycles. With my Ref 2SE phono I needed to change at 500 hours. Anyway certainly if you listen for shorter times as I do don’t expect to get maximum tube life