'running in' new h fi equipment
 

"Robert" wrote in message
om
My new Cambridge Audio amp and tuner both carry instructions that the
unit should be run continuously (playing music) for 36 hours "to get
it performing at its best".

Does anyone know what such 'running in' is supoposed to do?

Address buyer's remorse.

'running in' new h fi equipment
 

In message , Arny Krueger
writes
"Robert" wrote in message
. com
My new Cambridge Audio amp and tuner both carry instructions that the
unit should be run continuously (playing music) for 36 hours "to get
it performing at its best".

Does anyone know what such 'running in' is supoposed to do?

Address buyer's remorse.



The only things in my experience that change their sound in the first
few days of operation are loudspeakers. (And then not by much).
--
Chris Morriss

'running in' new h fi equipment
 

My new Cambridge Audio amp and tuner both carry instructions that the
unit should be run continuously (playing music) for 36 hours "to get
it performing at its best".

Does anyone know what such 'running in' is supoposed to do?

Is it running in, or just warming up?

My last two sets of speakers definitely "ran in" - in different ways;
the Rogers LS4as started off bright and thin, and filled out, whereas my
Monitor Audio Silver 8is started off dull and perked up.

Electronic components also improved over (a much shorter) time, but they
also do the same thing if they're unplugged for a few days. So much so
that I've given up unplugging my amplifiers when I go on holiday, and I
used to leave my old CD-player switched on all the time (the new one had
a standby mode).

Quite why things should take longer to warm up than they do to get
physically warm, I'm not sure. No doubt someone will reply in a minute
to say that good equipment doesn't do that, and it's just a figment of
my imagination!

Can't really comment on your imagination. :-)

However my experience is as follows:

That on some occasions the properties of electrolytic capacitors will vary
depending upon the use history and the quality of the caps. However my
experience is that leaving an amp unused for a few days or weeks has no
audible effect in general due to this.

Similar comment to the above about some connections. If the connections
are
not decently ohmic they may be affected by use, or by the unit being left
unused - particularly somewhere cold/damp.

Apart from the above, some components take a while to warm up. This may
affect the bias conditions in gain devices a little. You may also find
that
a mains transformer takes a while to warm up, and this can affect the
amount of mechanical 'buzz' it produces.

In general, though, I'd expect a unit to warm up and not really be
noticably different quite soon after being switched on, and not mind being
left off for many days. There are exceptions, but I'd tend to see them as
signs of questionable design, flaws, or poor storage/conditions of use.

FWIW at one time I used to do things like shove the amp I was working on
into the fridge overnight so I could check out the effect of a 'cold
start'
the next day. This can show up problems. However my experience was that
decently designed amplifiers should not be bothered. A tuner *might*
suffer
some tuning misalignment if the tuning elements are temperature sensitive.
A speaker may well be affected as the suspension stiffness, etc, may be
affected by temperature. The field produced by a permanent magnet is also
affected by temperature - but this should be a small effect for such
modest
temperature changes.

However, generalisations apart, I've no idea why Cambridge Audio would
make
such a statement. Ask them, and see if their explanation makes any sense!
:-)

It is quite possible to perceive changes as time passes for all sorts of
reasons. Our hearing changes during the day, and as we wake up, eat/drink,
are distracted/alarmed/bored, etc, etc. Also the air changes its acoustic
properties a little as it changes temperature and humidity, etc. Also the
level of background 'noise' can also affect perception. Listening to
sounds
also tends to cause our hearing to alter/adapt. Hence we may well hear a
difference if we turn on a system and play the same music a few times at
different times during a day, or from one day to another. But this does
not
have to mean that the equipment is changing its performance.

Slainte,

Jim

Some amps' frequency responses can alter during warm up. Whether this is a
reflection of poor design or the designer's intent is another matter.

One of my favourite amps sounds *very* different when first powered up,
compared with when it's hot, to the degree that a demonstration of it when
cold would not impress me whilst, when warm, I love it.

I have no trouble leaving it on, so this isn't a problem for me. While I may
be curious as to *why* this is the case, I don't really care that it is so -
I prefer it and that's all that's important.

'running in' new h fi equipment
 

In article , Chris Morriss wrote:
The only things in my experience that change their sound in the first
few days of operation are loudspeakers. (And then not by much).

My experience too. The ProAc Response D15s I bought a year ago sounded
very different to the demo pair for about the first hour of operation
but settled in to the familiar sound after the first day or so. Some of
that may have been my ears/expectations but not the first 60 minutes.

The dealer had previously tried to sell me the thesis of needing up to 6
months "running in." I think he was trying to "manage" no-fault returns.

BTW, I looked at the ProAc driver manufacturer's web site and they
recommended two hours of running in for brand new units before testing
their parameters.

--
John Phillips

'running in' new h fi equipment
 

In article , JustMe
wrote:


Some amps' frequency responses can alter during warm up. Whether this is
a reflection of poor design or the designer's intent is another matter.

I'd be interested to know which models do this, and by how much, and at
what frequencies, this change occurs. Not something I have encountered so
far as I can recall.

One of my favourite amps sounds *very* different when first powered up,
compared with when it's hot, to the degree that a demonstration of it
when cold would not impress me whilst, when warm, I love it.

Again, I'd be interested to hear the details.

I have no trouble leaving it on, so this isn't a problem for me. While I
may be curious as to *why* this is the case, I don't really care that it
is so - I prefer it and that's all that's important.

Well, it does seem like a 'problem' to me as it implies that the
performance will drift about with room temperature, variations in the music
power changing the temperatures of devices, etc.

KH in a recent issue of Hi Fi News did do some measurements that showed
that the distortion levels in some amps vary as they warm up. However
others don't do this. My recollection is that this has been a 'known'
possibility for decades. (I certainly worked on it when developing over 20
years ago!) Hence such things should in general be removable by correct
design in my experience. If the set sounds 'better' when 'warmed up' then
I'd prefer the design to give the 'better' performance almost from the
instant of switch-on. Not to have to leave the set on for a long time
first. Partly as this would be a minor irritation. Partly as, to me, it
seems like a sign that the designers have not investigated and tackled the
problem.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

'running in' new h fi equipment
 

Kalman Rubinson wrote in message . ..
On Mon, 25 Oct 2004 21:56:38 +0100, Ian Bell
wrote:

The thing is that it most likely was not the amp that changed throughout the
day but your perception.

Of course but so many people just will not understand.


Of course, I bet that is why they instruct you to run in the new
equipment by playing music on it for 36 hours. it's not really to run
in the equipment; it's to runn in the buyer. I imgaine that they
have reduced the number of returns they get from people who find that
they 'don't like the sound'.

I remember once testing loudspeakers on a system where you could
switch instantly between them. I found that if you listened to one
pair for too long then the others all started to sound inferior when
you tried them even if they were in fact much better speakers.

Robert

'running in' new h fi equipment
 

"JustMe" wrote in message
...
My new Cambridge Audio amp and tuner both carry instructions that the
unit should be run continuously (playing music) for 36 hours "to get
it performing at its best".

Does anyone know what such 'running in' is supoposed to do?

Is it running in, or just warming up?

My last two sets of speakers definitely "ran in" - in different ways;
the Rogers LS4as started off bright and thin, and filled out, whereas
my
Monitor Audio Silver 8is started off dull and perked up.

Electronic components also improved over (a much shorter) time, but
they
also do the same thing if they're unplugged for a few days. So much so
that I've given up unplugging my amplifiers when I go on holiday, and I
used to leave my old CD-player switched on all the time (the new one
had
a standby mode).

Quite why things should take longer to warm up than they do to get
physically warm, I'm not sure. No doubt someone will reply in a minute
to say that good equipment doesn't do that, and it's just a figment of
my imagination!

Can't really comment on your imagination. :-)

However my experience is as follows:

That on some occasions the properties of electrolytic capacitors will
vary
depending upon the use history and the quality of the caps. However my
experience is that leaving an amp unused for a few days or weeks has no
audible effect in general due to this.

Similar comment to the above about some connections. If the connections
are
not decently ohmic they may be affected by use, or by the unit being left
unused - particularly somewhere cold/damp.

Apart from the above, some components take a while to warm up. This may
affect the bias conditions in gain devices a little. You may also find
that
a mains transformer takes a while to warm up, and this can affect the
amount of mechanical 'buzz' it produces.

In general, though, I'd expect a unit to warm up and not really be
noticably different quite soon after being switched on, and not mind
being
left off for many days. There are exceptions, but I'd tend to see them as
signs of questionable design, flaws, or poor storage/conditions of use.

FWIW at one time I used to do things like shove the amp I was working on
into the fridge overnight so I could check out the effect of a 'cold
start'
the next day. This can show up problems. However my experience was that
decently designed amplifiers should not be bothered. A tuner *might*
suffer
some tuning misalignment if the tuning elements are temperature
sensitive.
A speaker may well be affected as the suspension stiffness, etc, may be
affected by temperature. The field produced by a permanent magnet is also
affected by temperature - but this should be a small effect for such
modest
temperature changes.

However, generalisations apart, I've no idea why Cambridge Audio would
make
such a statement. Ask them, and see if their explanation makes any sense!
:-)

It is quite possible to perceive changes as time passes for all sorts of
reasons. Our hearing changes during the day, and as we wake up,
eat/drink,
are distracted/alarmed/bored, etc, etc. Also the air changes its acoustic
properties a little as it changes temperature and humidity, etc. Also the
level of background 'noise' can also affect perception. Listening to
sounds
also tends to cause our hearing to alter/adapt. Hence we may well hear a
difference if we turn on a system and play the same music a few times at
different times during a day, or from one day to another. But this does
not
have to mean that the equipment is changing its performance.

Slainte,

Jim

Some amps' frequency responses can alter during warm up. Whether this is a
reflection of poor design or the designer's intent is another matter.

One of my favourite amps sounds *very* different when first powered up,
compared with when it's hot, to the degree that a demonstration of it when
cold would not impress me whilst, when warm, I love it.

I have no trouble leaving it on, so this isn't a problem for me. While I
may
be curious as to *why* this is the case, I don't really care that it is
so -
I prefer it and that's all that's important.


Be interesting to see if Jim comments on your lack of snipping or whether
he'll just comment on mine here....???

'running in' new h fi equipment
 

"John Phillips" wrote in message

In article , Chris Morriss
wrote:
The only things in my experience that change their sound in the first
few days of operation are loudspeakers. (And then not by much).

My experience too. The ProAc Response D15s I bought a year ago
sounded very different to the demo pair for about the first hour of
operation but settled in to the familiar sound after the first day or
so. Some of that may have been my ears/expectations but not the
first 60 minutes.

It's so boring watching true believers pile onto each other with more
ignorance and error.

'running in' new h fi equipment
 

It's so boring watching true believers pile onto each other with more ignorance
and error. (AK)

For your information, I would agree with others that I hear very little if any
difference with so called 'burn in'. "People who use valves" are no more
predictable than "people who use cars"

=== Andy Evans ===
Visit our Website:- http://www.artsandmedia.com
Audio, music and health pages and interesting links.

'running in' new h fi equipment
 

"Andy Evans" wrote in message

It's so boring watching true believers pile onto each other with more
ignorance and error. (AK)

For your information, I would agree with others that I hear very
little if any difference with so called 'burn in'.

That's very nice.

"People who use valves" are no more predictable than "people who use
cars"

That's a very gratuitous introduction of the valves/vinyl controversy.