Asking for scientific basis is reason not a wall. I would love to find a scientific basis for warm up. But I've yet to find a theory that supports it, and my own experience doesn't support it. I don't understand why you're taking this personally. Another aspect of those whole line of argument that confuses me is the idea that warm up would create warmer/fuller/smoother sound (or some other audiophile golden standard). If you take jitter as an example (which is caused by interference, not temp changes anyway), and if it's a question of timing being off between source and output, I don't understand why decreasing it would increase warmth or help the DAC reach other golden audiophile standards rather than simply eliminating noise and thereby creating a more accurate output. Same with any other change in performance.
I get it. When I got my Audio-GD R2R DAC, it said 400 hours of break-in. I agree with you that it seems to be conventional wisdom about leaving gear on, break-in, etc. I don't particularly ascribe to it, but I don't think it's unfair to ask the deeper question of why.
I will admit I let my um, passion get in the way of more reasoned discussion... Perhaps it was just "feeling frisky" over how bowled over I was by my own new gear? I don't know. I do apologize for coming in so hot and not trying a more reasonable approach first, though I really did try that at first. I think in analogies, it's the best I've got, ordinarily. I, too, would love an empirical study on such topics but I also just enjoy the slight mystery of it. There is some gear I've sworn I've heard improvements on - even if its just my brain acclimating to something, that still counts IMO - and others that I just have not. And I really did hear a change in Yggdrasil "Analog 2" when I had it back in 2018. Right out of the box, it's really not fun to hear. I don't know why. But after a week of constant music? It was fine. And I think it just needs to be "on," not even playing, to "warm up." Either way - cheers, and thank you for joining me in trying to deescalate a little
It’s not an “audiophile community” idea. The clocks literally need some time to reach operating temperature and stabilise.
My understanding is that they are designed to operate to spec within a temp range right out of the box (e.g., room temp).
Btw, what exactly is stabilizing? Crystal oscillators have a fixed frequency. Nothing changes there. So I am actually not sure I understand what you mean by that.
Here's an example of measured performance of a DAC chip -- not an R2R DAC -- that performs worse when warmed up and seems to have an optimal temperature at which is performs best, and possibly a case where the circuit designer using the chip should have maybe heat sinked it or otherwise cooled it so that it operates at optimal spec, base on temp. Will the differences in performance produce audible differences? Open to question. But that there are differences in performance based on temperature seems to be the case -- SMSL M500 Teardown & ESS ES9038Pro DAC Thermal Analysis
Why don’t you read up on it. Why do you think most dac manufacturers suggest that you leave it powered on at all times? Maybe you can set them all straight and explain to them that they have been fooled by an “audiophile community” myth.
I did read up on it. I've even built electronics myself. You've made a lot of assertions without backing up any of them.
The DAC has been powered on for about 16 hours now and sounds much better. When I get new gear the first thing I listen to with the new gear is something by Pink Floyd. It's been that way for 20 years. For the Bifrost 2 I chose the 2014 24/96 version of "The Division Bell". Cause I like it and I wanted to listen to high-res with the new DAC. I listened to the album all the way through. The DAC had only been on for an hour before playing the first tunes. Initial listening impression was that the bass was missing low end transparency and heft. The bass frequencies were there but didn't have the bloom and transparency they should. Something in the bass was definitely missing. Midrange was also more forward than I expected. Drum hit transients sounded like they were overshooting and too forward in the soundstage and imaging. Next up was the 24/88.2 version of "Random Access Memories" along with a quick compare against the CD version. Because high-res allows me to better hear how the DAC is behaving and changing as it warms up. "Random Access Memories" is one of the high-res albums that I use to evaluate how well gear does high-res. I know how that album sounds in high-res and how it sounds in CD and what the differences are. The differences are largely in the transparency of the bass. The bass has a sort of pillowy sound. The more transparent the gear is the more of that pillowy sound I hear. That pillowy sound was mostly missing. The DAC wasn't doing the bass transparency like I knew it should. The high-res and the CD sounded way too much alike. The DAC was playing high-res and making it sound like a CD. Bass drops in "Within" faded away way too soon. It is now the next day and the DAC has been on for about 16 hours. I'm listening to the high-res version of "Random Access Memories" again. And the BASS is back. The pillowy sound is here. The bass drops in "Within" are doing their thing. The bass in "Loose Yourself to Dance" hits hard and low like it should. The bass is doing all the things right that it was doing wrong last night. What a difference 12 hours of warmup makes. And I expect the DAC to get better as it warms up and burns in even more. I've only tried the single-ended outputs of the Bifrost 2 so far. Connected to my Liquid Fire amp and using LCD-2 Classic headphones. I'll get around to trying the balanced outputs eventually. But for now I'm enjoying my Liquid Fire amp and will continue to use it for the next week or so to keep things constant as I learn how this new DAC sounds.
Do you think that example implies that a similar phenomenon is occurring in all other dacs? Or all other dacs with that chip?
By the way, this effectively argues against warm up (which is to be expected, given that cooler temps are more conducive).
I understand. The crystal oscillator is just a reference. There is nothing there to stabilize. It's a crystal.
here's one of many explanations that you can find online explaining how TCXO's require warm up: TCXO vs OCXO - everything RF maybe take a break from building electronics (and knowing everything) and educate yourself
This is a link right next to the article you sent that clearly says warm up time is 15 seconds to 5 minutes. What is Warm-up time of an OCXO? - everything RF And I am still struggling to understand why increased clock accuracy would create a warmer and fuller sound, etc.
