breaking in a dac


well, i've finally done it. i bought a boulder 1012, after to listening to my dealer's demo off-and-on for several months. so, my questions (yes, i’ve searched--found nothing on point): (1) does a standalone dac benefit from break-in? (2) if, as i suspect, the answer to #1 is "yes," how best does one do this without scaring the dogs or the neighbors (i.e., do i need to power up my amp and speakers to normal listening levels)? (3) if i need a resistive load, can i jury-rig a device (all inputs and outputs are xlr)? TIA -cfb

BTW, for those sometimes mystified by internet-speak abbreviations, here's a great website primer:

http://www.computeruser.com/resources/dictionary/chat.html
cornfedboy
sean: i spoke to bruce vanallen at boulder amps about your and bob's interesting question. he gave me an explanation, tho i'm not sure i have a sufficient grasp of the technical argot to communicate it. but here goes my attempt: the analog section of the 1012 is always on, as is that portion of the digital motherboard used to powerup and control the display. thus, the digital and analog motherboadrs are always in a "warmed-up" mode. the boards are optically and mechanically isolated to assure there is no deleterious "cross-talk." the dsp, which is in its own shielded portion of the chassis, is powered on only when a digital input is selected. the dsp requires virtually no warmup, according to bruce. i hope this all makes sense. it did when bruce communicated it to me.

-kelly

ps- bruce sent me an email this am, saying my 1012 was on his desk and offering to deliver it today. now that's service! my dealer's sales manager (who lives in boulder) picked it up. i'll hafta wait 'til tomorrow am to get my hands on it. avalanche hockey on the menu tonite. -cfb
Yeah Kelly, PLEASE do keep us posted on that. I'm with Bob on his thoughts as we've both seen / measured drift in digital gear as it goes from cold to fully stable. This is besides the fact that most of us think analogue sounds best after a day or two also. I'd be curious as to how they get around this or what their thoughts are. Then again, if you don't like what they have to say, you could always send it over here. Bob and i are close enough that we could take turns sharing it : ) Sean
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bob: i figure i'll leave the pre/dac on 24/7, switched to the digital mode. even if i listen to a couple or three hours of lp's, the dac shouldn't be "stone cold." moreover, the line stage, which is likely more critically acclimated by warmup, will not have been cooled down atoll. just a guess, but i'll talk to bruce vanallen to get his views. let you know if my presumptions are wrong. i do, of course, appreciate your comments, as always. -cfb
That's a slick design but still makes me wonder...
Say you've been playing the phono awhile tonight, & now you want to switch to the CD. The whole digital section is stone cold; how is that going to sound optimum until after about 24 hours or so when the semiconductors attain thermal stabilization?
I'm sure they have this all figured out, but I know my SS isn't at its best until a day or so after power on. I don't know how they get around this problem - apparently it's not an issue.
bob: one of many really neat things the 1012 does is to power OFF the digital section power supply and transformer when the analog section power supply and transformer is powered ON (the line stage, obviously, is always on). so, yeah, you're right about my needing to separately break in the digital and phono stage sections of this piece. FWIW, there's an excellent review of the 1012 in the 12/01 issue of s'phile (don't agree with mr. scull's views on the dcs gear but, hey, it's all subjective, eh).

dan: thanx. now if i can just figure out how to arrange a "permanent loan" of a couple of a-50v's, i'll be closer to nirvana.

-cfb
I realized that I messed up a bit on my last post. I just checked the Boulder website (still drooling :-) here) & confirmed my suspicions that the 1012 is a DAC / pre combo, so my statement that "the preamp doesn't have to be powered on" is obviously wrong in this case (would apply correctly to a standalone DAC with separate pre).
So now Kelly, you'll also need to breakin the analog stage, the line stage, & the aes inputs. I believe that the phono board will terminate it's input regardless of input selector switch position, so that could likely be run simultaneously while the digital input is also cooking. Regarding your analog tuner & aes inputs, I wonder if those input stages terminate only when those switch positions are selected? Call Boulder to find out & if it does terminate then you can also breakin those simultaneously; if not, then obviously they will have to be done separately at a later time.
I hope this all makes sense; frankly I'm not accustomed to dealing with hardware at this performance level, but it's still nice to share a bit in your fun. Please do let us know how it all sounds; I'm sure that it'll be a real treat!
thanks for all the responses, guys. i'm supposed to get delivery of my new toy on monday, next (we'll see). i'm having it fitted with an st glass input, so i can take advantage of the matching optimized output on my accuphase dp 90, which i'll still be using for now. i'll also use some accrotec or trara six nines coax into the boulder's special adapter for it's aes/ebu inputs, so i can toggle between the inputs remotely. yes, this is my christmas gift to myself. -kelly
Congrats! I, too, used Bob's method for wont of skills to apply Sean's (used by technicians, allegedly to speed up the process). Do enjoy and be patient! I understand the Boulder's rahter complicated power & audio circuitry takes time to break in.
"regulator interconnect" should've read "regular interconnect". Sorry if you followed my directions and you blew something up : )

I forgot to mention congrat's to you Kelly. Hope you enjoy your new "gadget" and it does everything that you think it should. Now if it could only pay your bills, do your lawn, etc.. : ) Sean
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Hey Kelly just run the CD on repeat play, have your preamp selector set to load the DAC's output (just select THAT input) then listen (or not, your choice) it doesn't matter at all where you set the volume control which is downline from the input termination. Amp does not to be on, not even the preamp because it will still terminate the input. Run it for a few days & play one of those breakin CD's like the XLO etc.
& congratulations on your new toy - an early Christmas gift from you to you!
Geez you got it already! Why jury-rig anything? stay home and listen all day long, after a few days, perhaps you will notice a little improvement-if not then stay a few more days!
All components will "settle in" somewhat. The more signal that they pass, the faster that would occur. Since a DAC isn't passing much signal at all, you can speed up the process by simply rigging up a dummy load using the appropriate value resistors and a cheap XLR connector. Feed it a signal when your not using and simply swap the regulator interconnect into place for normal use. Like anything else though, my advice is to play it as often as possible : ) Sean