Break in period

Most components require some break in. Film capacitors will break-in over 100 to 400 hours. Resistors, tubes and the cabling will also break-in or settle as they are exposed to current.

I wouldn’t worry too much about it, just run the amps and enjoy. You’ll notice a slight improvement as the components settle in – no big deal. I wouldn’t bother leaving gear on 24/7.

Regards
Paul

"IMHO, in reality, one can select high quality electronics equipment that does not drift measurably or audibly in as little as a few hundred hours; equipment that can function accurately from day one and for many years."

Break-in has nothing to do with the quality of components. I have used TFTF V-caps on a few amps and noticed how they change during break-in. Care to name a better foil capacitor than a V-Cap?

when I upgraded mains from ATC 20's to ATC 100's I actually had to make an adjustment to the reduction in harmonic distortion in the extreme LF at higher SPL levels.

ATC 100 have less harmonic distortion at LF at high SP levels than ATC 20? Really

Did you measure distortion levels and how do you know it is harmonic distortions?

+++ No respectable engineer would deliberately design an amp with a significant drift in electrical response characteristics over 100's of hours +++

Really? Are you an engineer perhaps?

I am also somewhat amazed as to why you equate the phenomena of burning-in to something that is deliberately engineered? That is quite absurd. I replaced couplers in many-many amps. I most certainly did not do it to create the burn in phenomena – that is just a function of the cap I used – but I have almost always witnessed the caps settling down/burning in.

Simply because the bottom-of-the-barrel, cheap crap components used to manufacture Sony, Pioneer, Denon, Yamaha etc. does not exhibit this behavior, does not make them superior nor does it make their designer more 'respectable'. I can assure you, the Sony, Denon, Pioneer etc. engineer doesn't give a rats ass if his component is subject to burn in or not.

I opened an Onkyo DVD some time back and had electrolytics for coupling caps that probably retail for less than 1c each. Sure, you won't hear them settle in. They sound crap before settling, and equally crap afterwards.

I replaced the couplers in said Onkyo with $5 (yes, 5 bucks) worth std BG 16v 47uF caps. The owner is now beside himself at the improvement. And yes, he did notice the BGs burning in over the first 100 hours also, but I can assure you it sounds a lot better than the stock unit and then some.

Because your equipment does not exhibit burn in does not mean it doesn’t happen ... my $9.99 transistor radio also did not burn in. (Does that mean it better than my Audionote?)

Regards
Paul

Drubin. I suspect that all gear is subject to burn in. However, I have little experience with inexpensive gear and as such would be silly to argue against someone that has.

Shadorne, are you saying that engineers deliberately engineer their equipment to audibly burn-in? I have heard some far out theories before, but this one sets new standards.

+++ Often the part selection and design criteria are heavily influenced by the desired products useful life span. +++

Mmm yeah. This statement would have been even more interesting if there was any correlation between burn-in and reliability/life-span. There isn’t, but if you are theorizing that there is, then we have yet again set new standards for far out theories.

+++ Nobody wants a "lemon" out there that hundreds of customers complain about; the cost to make a manufacturing recall to get equipment to perform properly as originally specified to customers; the cost to reputation +++

Well it’s nice to see you’ve done Business Management 101, but again this has zero relevance to the phenomenon of burn in.

I guess you may find individuals that will send back V-Caps because they sound slightly better after 400 hours. Personally I elected to keep mine ... each time.

Regards
Paul

Shadorne, your second paragraph comes close. If you like the sound of lets say, Dynamicaps, and decide to use them when you build or modify an amp, they will change ever so slightly the first few hours of use. That is irrespective of your design.

However, this is not necessarily a lengthy process nor is a frustrating one. Dynamicaps do most of their settling within 4 hours or so, and I always get a big kick out of hearing the very subtle improvement as I spin the first 6 to 7 LPs. It’s almost like watching your child getting born, only less costly. Makes all the soldering worthwhile.

Tone arm wire and step-ups take forever to burn in. This is due to the very low voltages going through them. (< 0.005 volt in the case of many MCs). I put them on my cooker and run 2 volts through them for a few hours. Believe me, they’re well burned-in after that.

More than likely the stuff you bought were run for a few hours at the factory for shake down tests. That would all but run-in most components inside your gear.

Regards
Paul