Break in for new DAC

Thanks much

Amp doesn’t need to be on. The only few items that really benefit from break in are power supply caps that take about 200hrs and tubes that take about 100hrs. 
I would not be too obsessed about it unless it sounds terrible out of the box which is unlikely. Just listen and let it take its own course. 

Yes, that is the dilemma. I find that tubes tend to break in pretty quickly... say 10 to 20 hours. It is the solid state that takes time. So, I find that solid state tend to start off worse and really needs it to sound good. But that often tubed equipment sound really pretty good after 10 or 20 hours then improves (although often taking a lot more than 200 hours to achiieve it’s best sound). So, for a tubed DAC I would run it ten or twenty hours and then just enjoy it. I’m pretty confident you will really like the sound and then it will simply appreciate it more as time goes on. 

The stuff I have felt I just needed not to listen to it until it was broken in has been all solid state. 

Almost all break-in is between your ears.

OK and with expectation of a pile on and I stress IMHO, 200-300 hours is absolute nonesense, dripping with the secret sauce known as expectation bias!

DAC’s generally need no real break in period past voltage and component stability at most a couple of hours out of the box, then and in your situation, a few minutes for the tubes to warm up in daily use.

Your Ray tubes have already gone through long periods of quality testing and matching, so at worst long enough for them to stabalize from cold is all that’s needed.

I run a EAR Yoshino 912 all tube pre and a fully restored and upgraded stereo tube power amp, with a Lumin X1 streamer. Lumin say leave the power-supply on and the unit in standby (I think aound 5-8 watts) it is then literally seconds before it performs optimally (now that is honesty) Even new out of the box they are confident that a few minutes stabalization is all that’s required.

I allow the Pre Amp about 15 minutes as per the late great Tim de Pavaracini’s advice, since the preamplifier was soak tested before going to the customer and thier tubes had been hand picked for matching and performance characteristics.

The Power Amp with all that heavy Iron and huge filter cap reservoirs, is a slightly different beast of course. I have noticed that its sound does improve from cold switch on and over time since the open heart surgey it has seemed to improve. I was psycologically expecting that as there are electronics and physics that are known parameters, at work.

So I have adopted a soft on regime which is 15 minutes in heater only mode, then switch in HT circuit using the standby allow 10-15 minutes and all is optimal and kind on the amplifier.

I understand some time for a speakers to improve as they are electromechanical components and newly constructed drivers although tested, will benefit from a few hours of running in and some manufactures do this for cones surrounds and spiders to get used to their marriage but beyond 20 hours or so of varied program input, I’d say the changes would be negligible.

If manufacturers really believe this craziness, then how are they evaluating the sound of their products in a quality control environment? Maybe they should be "running" or "burning" in the gear before shipping to the retailer or customer.

Why should the customer have to "run in" or condition their product for them, its an extra cost to be added to the purchase price. How will they ever know that it sounds the way the manufacturer intended?

200-300 hours before it peforms as it should is nearly 43 days of constant use 8 hours a day!

Maybe this is manufacturers exploiting HiFi Folklore in making sure the customer gets psyco-accoustically conditioned to the sound of a product than that product changing over time.