Every amp in one
 

JustMe wrote:

Many of you chaps believe that the Peter Walker(?) "straight-wire" ideal is
that which any "hifi" designer should aspire to construct.

Do you think that this is attainable?

To all intents and purposes it has been attained in all good SS amps
(And a handful of exceptional valve amps)

Every amp in one
 

JustMe wrote:

If the latter then how can you quantify what is a "proper" adjustment of an
eq, beyond whatever the listener prefers?

Its just a tool. you can use it compensate for deficiencies in your
system. eg. speakers with poor frequency repsonse or a nasty room accoustic.

Every amp in one
 

"JustMe" wrote in message



"Arny Krueger" wrote in message



Wise audiophiles wishing to get off the new amplifier merry-go-round
would cut to the chase and just get some parametric eqs for their
own system. Then (and here is the hard part) they would learn to
adjust them properly by ear.

This probably comes down to semantics: do you view an audiophile as
someone who specifically seeks "straight-wire" sound, or is an
audiophile anyone who is critical of, seeks out and appreciates what
they perceive to be superior sound?

It's obviouisly highly naive to believe that you're going to pick equipment
that has ideal response in your listening room without some kind of further
adjustment.

If the former then wouldn't they be better off purchasing the
"straight-wire" source, amp and speakers, and not playing with eqs to
compensate for the inferiority of "curly-wire" products?

Show me a room and speaker with "straight-wire" response and I'll try to
answer your question more directly.

If the latter then how can you quantify what is a "proper" adjustment
of an eq, beyond whatever the listener prefers?

Well that's just it - in the end everybody needs to impose their preferences
on system performance. The idiot's approach is to go to the high fi store
and spend money on what sounds good there. The wise man's approach is to get
the best, most suitable equipment one can, and then be prepared to make such
intelligent adjustements as are required in the listening room.

Every amp in one
 

"Ian Molton" wrote in message
...
JustMe wrote:

Many of you chaps believe that the Peter Walker(?) "straight-wire" ideal
is
that which any "hifi" designer should aspire to construct.

Do you think that this is attainable?

To all intents and purposes it has been attained in all good SS amps
(And a handful of exceptional valve amps)

Please can you suggest some examples? (Hopefully I will know at least one!)

Every amp in one
 

Ian Molton wrote:



I dont see how it can be since to do so the box would need to have
knowledge of (at least) your room acoustics and speaker properties, and
(preferably) the room characteristics the 'target' speaker is used in.

(on top of that you'd need a profile for the other speaker, of course.)

The assumption for that box, is that its driving either a clean PA, or a
desk, so it only needs to take into account the sound produced by
different speakers with different mikeing methods.

Remember we are not talking HiFi speakers here, the difference in sound
(for example) between a open backed AC30 and a closed Marshal 4*12 is
know and it does a good job of duplications. I don't own one, but have
played with one for some time. Its a useful box.

--
Nick

Every amp in one
 

In article , JustMe
wrote:


What you *could* do, though is something like the following.

Play music through the Alchemist into a pair of speakers. While doing
so, connect leads to the speaker terminals and record the signals
there onto CD-R using a reasonably quality recorder. Note the signal
level with a meter.
[snip details]

I would be happy to try something like this blind. I'd be really curious
to see if such "filters" were possible and whether I would be able to
tell differences, or recognise my favourites as superior to those which
I'd previously rejected.

The snag is that even if the above allowed you to 'record' or 'reproduce'
the specific effect of a given amp, you may still need it as the 'filter'
unless we could establish what it was doing to be able to 'mimic' it in
some other way. That said, what your reactions were to such a test would be
interesting.

Presumably the playback equipment would have to be that which is
considered as "straight-line" - the CD player and amp?

Depends what you are trying to detect or establish. For example, it may be
easier to determine if you think the sounds are 'similar', but harder to
establish what it involved or what may affect the degree of 'similarity'
(if any).

But is there a danger of a cumulative effect? If I use the same speakers
in replaying the signal as it's been recorded from the system, would the
effects of the speaker's balance not be duplicated?

Not their conversion efficiency, etc. Just the effect of their input
impedance upon the signal at the speaker terminals. In effect, this is the
'break point' in the comparisons as I described them.

Would this be cumulative? Presumably, any small deviance from
"straight-line" in the CD or amp's replay would undermine such an
experiment.

It may do. However it may also turn out to be small enough not to have a
significant effect on the results.


In principle, you can perform the kinds of tests I am describing in
various ways. e.g. Do a 'speaker terminals' recording using amp 'A',
and then another using amp 'B'. Then compare the two recorded CD's
using first 'A' and then 'B' to see if you can distinguish them
in each case, and hear the effects of 'AA' 'AB' 'BA' and 'BB' if
you see what I mean.

Also, could record one channel (left or right) using 'A'. Use the
power amp input for one recorded channel, and the loudspeaker
terminal signal for the other recorded channel. Repeat this
for amp 'B'. Then replay each of the recorded 'mono' discs via
'A' and then 'B' and listen for any departures for 'mono'.

None of these tests in themselves are 'perfect' in terms of
excluding all other effects, etc. However by doing a series
of such tests you might be able to form some conclusions about
what is happening that is consistent with the comparisions they
represent.



Many of you chaps believe that the Peter Walker(?) "straight-wire" ideal
is that which any "hifi" designer should aspire to construct.

The designer should design what people want. This way he gets to eat. :-)

The snag is, no-one can fully define that, and people argue about what they
want. ;- Hence you just have to make a best guess...

I personally tend to prefer amps with a fairly flat response and low
distortion. (Both terms relative to what can be expected compared with
other places in the chain. e.g speakers and room acoustics.)

Do you think that this is attainable?

I would say 'yes' with the qualifiers that:

1) Close enough to the 'Walker' definition so that any changes produced by
the chain in which the amp is a part tend to be mainly due to things like
the speakers, room acoustics, decisions made by those who made the
recording, etc. i.e. sufficiently close that departures from the 'Walker'
definition are small w.r.t. these other sources of departure from an ideal.

2) Still may not be what everyone wants. :-)


FWIW I feel that a lot of equipment comparisions (and arguments) tend
to become hung up on worries about things not being 'identical. However
in practice I think what matters is a set of slightly different levels
of comparison. e.g. Are the units 'indistingushable' in the conditions
of use? (i.e. may well differ, but in ways that are small enough to
go un-noticed). Or are any differences between two units so small that
they really don't matter much when other items in the 'chain' produce
much more noticable effects?

Also, some 'effects' may be useful in some contexts, but not others.
The obvious example is that if your speakers/room cause a change in
response at some frequencies, you might prefer an amp in the system
that counteracted this. However if so, my personal preference would
be to know this was happening so it was a conscious decision to
do this, not an 'accident' in the sense that you just find a given
system preferrable but have no idea why. Knowing the reasons gives
you the ability to make other changes which you might prefer at a
later date, and not be 'tied' to a given unit without knowing
why this is the case...

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

Every amp in one
 

On Fri, 19 Nov 2004 15:16:22 -0000, "JustMe" wrote:

"Ian Molton" wrote in message
...
JustMe wrote:

Many of you chaps believe that the Peter Walker(?) "straight-wire" ideal
is
that which any "hifi" designer should aspire to construct.

Do you think that this is attainable?

To all intents and purposes it has been attained in all good SS amps
(And a handful of exceptional valve amps)

Please can you suggest some examples? (Hopefully I will know at least one!)

Audiolab 8000S, and the 8000P power amp. Common enough, and
essentually 'blameless', as Doug Self would say.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Every amp in one
 

"Stewart Pinkerton" wrote in message
...
On Fri, 19 Nov 2004 15:16:22 -0000, "JustMe" wrote:

"Ian Molton" wrote in message
...
JustMe wrote:

Many of you chaps believe that the Peter Walker(?) "straight-wire"
ideal
is
that which any "hifi" designer should aspire to construct.

Do you think that this is attainable?

To all intents and purposes it has been attained in all good SS amps
(And a handful of exceptional valve amps)

Please can you suggest some examples? (Hopefully I will know at least
one!)

Audiolab 8000S, and the 8000P power amp. Common enough, and
essentually 'blameless', as Doug Self would say.

Well I know these amps very well and used to own an 8000S, so I'd find that
to be a useful reference.

So, who's going to build me an Alchemist Kraken APD6aII filter for use with
an 8000S then?

I presume such a filter could be built to be inserted via the 8000S's
pre-power loop, enabling a very simple switch between "8000S straight-line
integrated" and "8000S Pre/Power/Alchemist mode" :o)

I'm happy to provide the amp for measurement and, from what I've read,
Stewart will be glad to provide an environment for a double-blind test ;o)

BTW I'm not making any claims to right/wrong on any issue here, but I find
this a very interesting concept and, to me at least, the results of such a
test would have a profound impact on the way I would look at different amps
and the choices made by those who design and build hifi products. It would
also make an interesting article for a decent hifi mag and a good website
too.

Of course, some of you may think that this is nothing new and an unrealistic
quest, but I'm not aware of a hifi product "simulator" and would be glad to
buy one at a reasonable price, if it worked accurately.

Every amp in one
 

JustMe wrote:

To all intents and purposes it has been attained in all good SS amps
(And a handful of exceptional valve amps)

Please can you suggest some examples? (Hopefully I will know at least one!)

The Quad405 isnt bad. There are better.

in the valve camp other people have mentioned examples of transparent amps.

Every amp in one
 

JustMe wrote:

So, who's going to build me an Alchemist Kraken APD6aII filter for use with
an 8000S then?

Theres a bit of a gap betwixt theory and practice here... whilst linear
amps arent theoretical, the 'amp emulator' is and would need
considerable research to get right.