burn in - how important?


Over the years following Agon forums I have read many postings about burn in and been fairly sceptical, as many items I have bought over the years have changed SQ very little or at all, after years of use. Recently I replaced my Rogue Stereo 90 with a used EAR 534 power amp. Out of the box it looked brand new, all nice and shiny. I plugged it into my also fairly recently acquired Aesthetix preamp and was horrified by the thin sound, little or no soundstage and was relieved I hadn't yet sold the Rogue. Now I knew why it had been up for sale or did I. Maybe I was too lazy to plug in the Rogue again but I left the EAR in place and after about 30 hours I noticed a difference, more depth, wider soundstage, Now after about 100 hours - WOW huge soundstage, both depth and width. great tight bass, shimmering highs. Now I know why Tim De Paravicini was regarded as a genius and sorry for the seller who probably had not given the unit a chance to burn in properly. I decided to biwire it into my ML Vantage speakers and cut out the second Acurus a250 amp which I was using in biamped format. There was hardly any difference, maybe quieter and more detailed overall. Who would have thought an EL 34 based 55wpm channel Class A amp could drive a pair of electrostatic hybrid speakers rated at 4ohms. OK no longer a sceptic about burn in but a firm believer. What has been your experience?

128x128mazian

@millercarbon - indeed! When I got my Herron phono amp and line-stage amp, Keith said they'd need 150 hours or so to sound their best. As you say, they sounded just fine out of the box, but Keith was not wrong....

As far as I can remember burn in has been very obvious on all new stuff I have purchased, since I got high end gear… 40 years. Over the last few years I have (for various reasons) broke in about five new pieces of Audio Research Reference electronics and the pattern has been identical. Hugh difference (starting from thin, closed in, limited bass) for about 100 hours… then remarkable improvement, then switching back and forth from good to bad and visa versa around 120 hours… then slow improvement through 600 hours (fastest at first). This time, I did notice improvement over 600 - 1,000 hours… small but noticable… I had read about this before but never experienced it (usually because it was covered up by me switching power cords or interconnects or something.

 

This has always been a real pain because I usually go through an upgrade cycle… and want to get through it as fast as possible…. But I never buy everything at once so getting hundreds of hours in is hard. I have an extra Schiit system just to break in stuff.

Does anyone notice similar improvements in video equipment?  Colors getting deeper?  Colors becoming correct?  Improvements with higher priced power cords?  

I'm not an owner of any of the high end gear you folks own.  But I certainly have noticed a difference in my vintage equipment now that it has settled in and if I leave it on for a few hours before listening....huge difference.  And I think my '86 Monster speaker cables have burned in fairly well.  Happy listening!

Not burn-in but warm-up. In reply to an email, Nelson Pass said his First Watt F8 reaches thermal equilibrium after an hour. He also said you can leave it on all the time if the waste of electricity is not a problem for you.