How does an amp contribute to soundstage?

Archived from groups: rec.audio.tech (More info?)

On Fri, 09 Sep 2005 11:53:10 -0700, hoarse with no name <no@2spam.com> wrote:



>In amp reviews the quality of the soundstage produced by the amp is
>often mentioned. I know from listening comparisons that the imaging of
>some setups is better than others, but I have always credited the
>speakers with this and filed it under the More Art Than Science
>category. Can an amp improve the soundstage/imaging provided by speakers
>and if so, how so?

Yes; if the amp doesn't have equal response between the channels then the
image is going to be scattered left/right depending on frequency. Ie: if the
left channel is +2db at 1khz and the right channel -1db at 1khz, but equal at
2khz and the other way around at 4khz, the imaging is going to go to hell. It
doesn't really matter for imaging if both channels aren't terribly flat,
as long as they are fairly close to each other. Ditto for speakers.

Archived from groups: rec.audio.tech (More info?)

"Arny Krueger" <arnyk@hotpop.com> wrote:

> "AZ Nomad" <aznomad@PmunOgeBOX.com> wrote in message
> news:slrndi48pt.cah.aznomad@ip70-176-155-130.ph.ph.cox.net
>> On Fri, 09 Sep 2005 11:53:10 -0700, hoarse with no name
>> <no@2spam.com> wrote:
>>
>>
>>
>
> Many such differences can be attributed to traditional
> analog potentiometer-type volume controls in receivers,
> preamps, and integrated amplifiers. Many surround receivers
> have scrapped analog volume controls for digital
> level-setting via DSP, which generally offers precise
> channel balance.
>
>
>

I don't wish to start a long argument about this or change the intent of
the thread but I can't help but say that I disagree with that! The reason
DSP chips are being used in place of discreet potentiometers is cost and
the ability to use remote controls. Mainstream electronics manufacturers
NEVER do anything because it offers better sound. In fact I would say that
their designs generally result in poorer sound when they deviate from past
practices. There is absolutely nothing wrong with a good quality
potentiometer in the signal stream.

my 2¢

Archived from groups: rec.audio.tech (More info?)

"wß" <wb@nomail.com> wrote in message
news:04AUe.10419$vJ4.2411@tornado.ohiordc.rr.com
> "Arny Krueger" <arnyk@hotpop.com> wrote:
>
>> "AZ Nomad" <aznomad@PmunOgeBOX.com> wrote in message
>> news:slrndi48pt.cah.aznomad@ip70-176-155-130.ph.ph.cox.net
>>> On Fri, 09 Sep 2005 11:53:10 -0700, hoarse with no name
>>> <no@2spam.com> wrote:
>>>
>>>
>>>
>>
>> Many such differences can be attributed to traditional
>> analog potentiometer-type volume controls in receivers,
>> preamps, and integrated amplifiers. Many surround
>> receivers have scrapped analog volume controls for
>> digital level-setting via DSP, which generally offers
>> precise channel balance.

> I don't wish to start a long argument about this or
> change the intent of the thread but I can't help but say
> that I disagree with that! The reason DSP chips are being
> used in place of discreet potentiometers is cost and the
> ability to use remote controls.

Actually, it comes down to cost and cost.

It's never been impossible to find pots that would track and
assemble them so they were in-synch. It all just costs
money.

OTOH a shaft encoder and a few more lines of code in a DSP
program that is already there, is hard to beat in terms of
technical performance or cost.

>Mainstream electronics
> manufacturers NEVER do anything because it offers better
> sound.

Seems cynical, but sound is not the only reason, or even the
most driving reason in every case.

> In fact I would say that their designs generally
> result in poorer sound when they deviate from past
> practices. There is absolutely nothing wrong with a good
> quality potentiometer in the signal stream.

Except for paying for it and keeping it working well over a
long period of time.

The dual pots in my APT and Conrad Johnson preamps have
stood the test of time, but they weren't cheap.

Archived from groups: rec.audio.tech (More info?)

AZ Nomad wrote:

[soundstage]

> Yes; if the amp doesn't have equal response between the channels
> then the image is going to be scattered left/right depending on
> frequency.

I considered front to back (yes, in stereo!) and up and down, and width
of back stage compared to width of front stage and interval between
direct sound and onset of reverb and distance between performer/sound
source and reflecting surface in my follow up.

> Ie: if the left channel is +2db at 1khz and the right channel
> -1db at 1khz, but equal at 2khz and the other way around at 4khz,
> the imaging is going to go to hell.

No, well for panpotted multimono perhaps, but not for stereo. There will
of course be a difference in stereo spread when comparing, but it is
almost not at all what imaginng and sound stage is about.

> It doesn't really matter for imaging if both channels aren't
> terribly flat, as long as they are fairly close to each other.
> Ditto for speakers.

The sense of hearing comes with a wonderful autocorrelator, and it is
used to the transducers having a wildly varying frequency response for
all kinds of reasons, such as amount of earwax, amount of head hair and
degree of functionality of eustachian tube. What it has a problem with
is handling an additional layer of early reflections that obscures and
smears what is in the recording, so obviously room acoustics is of major
importance.


Kind regards

Peter Larsen

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