The effects of mains conditioners
 

In article , Arny Krueger
writes
"harrogate2" wrote in message


Have to disagree with that. The main advantage of a regulated supply
is a lower supply impedance, which gives the most noticeable effect in
the form of considerably better controlled and cleaner bass.

While intuition might lead one to this conclusion, bench tests and blind
listening tests don't.

I'm not saying that we should go out of our way to give the power supply a
high output impedance, but in fact a well-built traditional power supply
composed of passive filtering components simply gets the job done.

For example, a typical 20,000 uF filter capacitor with minimum ESR has an
impedance of about 0.07 ohms at 120 Hz, 0.13 ohms at 60 Hz and 0.40 ohms
at 20 Hz. The output impedance of a standard power supply is no greater than
this.




Might it be to due with simple lack of voltage regulation and some amps
perhaps sag badly when driving near their limits?...
--
Tony Sayer

The effects of mains conditioners
 

In article , harrogate2
wrote:

"Pooh Bear" wrote in message
...

Requiring a regulated power supply for the main power supply rails
in an
audio amp is a sign of defective design in the power amp stage IMHO.

It's perfectly easy and practical to design a power amp that rejects
power
line ripple and performs superbly.


Graham


Have to disagree with that. The main advantage of a regulated supply is
a lower supply impedence, which gives the most noticable effect in the
form of considerably better controlled and cleaner bass.

Only if the amplifier is sensitive in the relevant way to variations in the
rail levels. "Pooh's" point is that it is quite possible to design the amp
not to be sensitive in this way. I'd agree with him as I spent some years
doing this.

FWIW I did start off assuming I'd use regulated rails, but found their
disadvantages outbalanced their advantages, so ended up putting the design
effort into making a better amp, than dividing the effort between amp and
stabilisers.

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

The effects of mains conditioners
 

tony sayer wrote:

In article , Arny Krueger
writes
"harrogate2" wrote in message


Have to disagree with that. The main advantage of a regulated supply
is a lower supply impedance, which gives the most noticeable effect in
the form of considerably better controlled and cleaner bass.

While intuition might lead one to this conclusion, bench tests and blind
listening tests don't.

I'm not saying that we should go out of our way to give the power supply a
high output impedance, but in fact a well-built traditional power supply
composed of passive filtering components simply gets the job done.

For example, a typical 20,000 uF filter capacitor with minimum ESR has an
impedance of about 0.07 ohms at 120 Hz, 0.13 ohms at 60 Hz and 0.40 ohms
at 20 Hz. The output impedance of a standard power supply is no greater than
this.


Might it be to due with simple lack of voltage regulation and some amps
perhaps sag badly when driving near their limits?...

Voltage 'sag' on the power supply need have no influence on the audible
performance of a power amp, in the same way that power line ripple need have no
effect, given competent design.

Sure, it restricts the max volts at the output but so does the voltage loss of a
regulated supply.

You'll actaully get better dynamics, like for like, with an *unregulated* supply
due to the absence of the volt drop in the regulation.


Graham

The effects of mains conditioners
 

In article , Pooh Bear rabbitsfriendsand
writes


tony sayer wrote:

In article , Arny Krueger
writes
"harrogate2" wrote in message


Have to disagree with that. The main advantage of a regulated supply
is a lower supply impedance, which gives the most noticeable effect in
the form of considerably better controlled and cleaner bass.

While intuition might lead one to this conclusion, bench tests and blind
listening tests don't.

I'm not saying that we should go out of our way to give the power supply a
high output impedance, but in fact a well-built traditional power supply
composed of passive filtering components simply gets the job done.

For example, a typical 20,000 uF filter capacitor with minimum ESR has an
impedance of about 0.07 ohms at 120 Hz, 0.13 ohms at 60 Hz and 0.40 ohms
at 20 Hz. The output impedance of a standard power supply is no greater than
this.


Might it be to due with simple lack of voltage regulation and some amps
perhaps sag badly when driving near their limits?...

Voltage 'sag' on the power supply need have no influence on the audible
performance of a power amp, in the same way that power line ripple need have no
effect, given competent design.

Sure, it restricts the max volts at the output but so does the voltage loss of a
regulated supply.

You'll actaully get better dynamics, like for like, with an *unregulated* supply
due to the absence of the volt drop in the regulation.

Eh?, Volt drop?. The point of a reg supply is to maintain the voltage,
the drop should be across the regulator device as such?.....

--
Tony Sayer

The effects of mains conditioners
 

In article , tony sayer



Eh?, Volt drop?. The point of a reg supply is to maintain the voltage,
the drop should be across the regulator device as such?.....

But the o/p voltage *will* still tend to drop under load. It is just that
the regulation/stabilisation will attempt to keep this change small.

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

The effects of mains conditioners
 

In article , Jim Lesurf jcgl@st-
and.demon.co.uk writes
In article , tony sayer



Eh?, Volt drop?. The point of a reg supply is to maintain the voltage,
the drop should be across the regulator device as such?.....

But the o/p voltage *will* still tend to drop under load. It is just that
the regulation/stabilisation will attempt to keep this change small.

Slainte,

Jim


Suppose its all a question of degree then....
--
Tony Sayer

The effects of mains conditioners
 

In article , tony sayer

wrote:
In article , Jim Lesurf jcgl@st-
and.demon.co.uk writes
In article , tony sayer



Eh?, Volt drop?. The point of a reg supply is to maintain the
voltage, the drop should be across the regulator device as such?.....

But the o/p voltage *will* still tend to drop under load. It is just
that the regulation/stabilisation will attempt to keep this change
small.

Slainte,

Jim


Suppose its all a question of degree then....

no, no. That's temperature... :-)

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

The effects of mains conditioners
 

tony sayer wrote:

In article , Pooh Bear rabbitsfriendsand
writes

Voltage 'sag' on the power supply need have no influence on the audible
performance of a power amp, in the same way that power line ripple need have no
effect, given competent design.

Sure, it restricts the max volts at the output but so does the voltage loss of a
regulated supply.

You'll actaully get better dynamics, like for like, with an *unregulated* supply
due to the absence of the volt drop in the regulation.

Eh?, Volt drop?. The point of a reg supply is to maintain the voltage,
the drop should be across the regulator device as such?.....

To provide a regulated supply of say 40 Volts requires an unregulated input to the
regulator of around 50 V most likely. Hence the 'volt drop' is 10 V.

I'd rather have the extra dynamics of connecting the amp direct to the 50 V than
bother with a regulated supply.

As I've said - it's only a poor amp design that is power supply sensitive.


Graham