Burning in

[Dave the bass]

Originally Posted by Audiognome

But cables? No, that doesn't make sense. In that case, I think it is the listener that is "burning in" !

Ah...yeah...but... what about the coil (of wire) in a loudspeaker? My little Fostex 167's have changed their sound drastically since first power-up (and I had a reference).

...or is that more of a mechanical burn-in?

DTB

[Richard]

Baggus,

Quite right, well known of valves. They start off bright and burn in to a stable state that they maintain for most of their life before going off. I suppose they are electro mechanical or electro chemical in that impurities are burned off and gas molecules are gettered during burn in. Brimar used to advertise that new valves every year would bring back the life to your radio. It did, for a few weeks!

Nigel and Lee,

No disagreement at all, I think we all recognise,
1) heat drift in components and circuits and
2) age drift where a component ages out of tolerance. The most common (apart from outright failures) being high value (Megs) carbon resistors which are commonly found at 2 or 3 times their nominal value but otherwise working fine.

Neither apply here. I tend to agree with Neal and others that the major factor may be the valves and possibly the capacitors. I hear valves and caps change after almost every new installation.

Other components I know sound different to each other (such as carbon v metal resistors, pio v plastic caps) but that is not the same as changing. They may change too of course, along with wire and joints etc but I can only say I've really noticed valves and caps.

Rich

[John T]

Originally Posted by Baggy Trousers

Messrs Leak, Lowther, Rogers et al never bothered to mention it. If they had conjured the dreadful expression, they would have said "Plug and play - straight out of the box". But, frankly, I just cannot see the urbane Peter Walker saying something as banal as that . . .

Oh yes he did!! At a lecture, I remember him saying something along the lines of, " In order to reach its maximum performance potential, all new equipment should be allowed some time for the individual components to "settle down""

What's more, in those days, the performance of amps was measured almost entirely by their THD figures - the actual quality of the sound was mainly an afterthought!

[Richard]

Originally Posted by Dave the bass

Ah...yeah...but... what about the coil (of wire) in a loudspeaker? My little Fostex 167's have changed their sound drastically since first power-up (and I had a reference).

...or is that more of a mechanical burn-in?

DTB

Dave,

Yes a mechanical break in of the surround and cone probably. Well known with speakers, new ones sound awful for many months, stiff/dead/lifeless, and some folk will say years.

I personally think speakers may be also be a big factor in the change of sound that some notice with "warm up". The speakers are a real mechanical weak link in the chain and subject to variation in performance due to temperature in partic. Electronics should really stabilise fairly quickly after switch on but mine for instance seems to need longer, maybe an LP side before coming to life.

Rich

[Dave the bass]

Originally Posted by Richard

Dave,

Yes a mechanical break in of the surround and cone probably. Well known with speakers, new ones sound awful for many months, stiff/dead/lifeless, and some folk will say years.

I personally think speakers may be also be a big factor in the change of sound that some notice with "warm up". The speakers are a real mechanical weak link in the chain and subject to variation in performance due to temperature in partic. Electronics should really stabilise fairly quickly after switch on but mine for instance seems to need longer, maybe an LP side before coming to life.

Rich

Ha! I nearly answered my own question, now thats talent innit

DTB

[Deco-Doctor]

What I find curious about this 'burning in' process is that in most cases folk seem to report that the sound always gets better after burning in, there seems to be few cases where the opposite is true. I wonder why this is.

[alnewall]

Well i'd like to be the exception to the rule.
I just spent two weeks swapping a number of different input caps on the DAC. One of the small mks caps sounded lightweight at first then somewhat better(not much) then after a few hours it seemed to go rather bright and coarse sounding at which point i chucked it.
Most of them didn't change noticeably at all. But i put this down to the tiny signals not having much impact on the caps.
Could be wrong.
The Vishay MKP1837 that i finally settled on did get better after a couple of hours.

Maybe people prefer to recount their successes than their failures.

[Stratmangler]

Originally Posted by Dave the bass

My little Fostex 167's have changed their sound drastically since first power-up (and I had a reference).

DTB

Does this mean that they sound worse now ?

I would have thought they had changed dramatically for the better - and yes it is down to the various drive unit parts all bedding in properly.

Sorry for being a pedant (or should that be peasant).

Chris

[Baggy Trousers]

Originally Posted by John T

Oh yes he did!! At a lecture, I remember him saying something along the lines of, " In order to reach its maximum performance potential, all new equipment should be allowed some time for the individual components to "settle down""

What's more, in those days, the performance of amps was measured almost entirely by their THD figures - the actual quality of the sound was mainly an afterthought!

An afterthought more successful than many of today's forethoughts, I would venture!

Thank you, John - it's nice to think that I'm not the only one of sufficient "maturity" to have met him, although he died only a few years ago so perhaps I'm still up here on my own . . .

My reference to "banal" was in respect of the "plug and play" nonsense rather than his technical expertise which was formidable, particularly when in association with D T N Williamson. When I wrote this, I was remembering an occasion years ago in Cambridge when I accompanied him on a hotel piano in a Handel sonata - he was an accomplished flautist and a delightful man.

I am happy to stand corrected - I suppose "settling down" might well be the same thing as "burning in" but in those halcyon days, there was no specific mention of the latter, as far as I can remember. Unwittingly, you have put the silly thought in my mind that next week's lecture will be "Harold Leak on Tube Rolling".

I really must go and do something useful . . .

[Dave the bass]

Originally Posted by Stratmangler

Does this mean that they sound worse now ?

I would have thought they had changed dramatically for the better - and yes it is down to the various drive unit parts all bedding in properly.

Sorry for being a pedant (or should that be peasant).

Chris

Yes Chris, they changed for the better. I writted on the DTB Vs MLTL thread that when first powered up they sounded gutless but over time they've matured into a lovely thing. (Like me some might say, tha Mum )

DTB