Mains filters
 

You asked me to post details of the unit which I had seen.
To meet your request I did this, without an opinion or an
interest eith for or against.

Don't suppose you have;)


Since then I have been able to find out the sales figs for
the Scandi countries. I am told the highest sales within the EU
are to the UK. There is a "huge" mark-up. So someone is making
a pile of cash. From your bitterness, I deduce it is not you:-))


Me bitter?, nah!, wish I was as bent as some people who sell/ supply
these things but I can't bull**** like they do and prey on the gullible.

Do you think that the above statement "filtering the mains to make your
TV picture sharper" to would stand scrutiny with sensible double blind
testing, or even the trades descriptions act?..

--
Tony Sayer

Mains filters
 

In article , Arny Krueger
writes
"tony sayer" wrote in message

In article
, Arny
Krueger writes
"tony sayer" wrote in message

Rane, a U.S. pro audio gear manufacturer with a very
solid reputation for conservative technology claims
that some of their gear (like mic preamps) showed a SNR
advantage when the power transformer was moved out of
the box and into a big plastic wart on the power cord.

http://www.rane.com/rap.html

Reasons to use external pwoer supples:

"Better Audio Performance. Removes the hum source, i.e.
the AC line transformer and all primary circuits
resulting in quieter noise performance, without the
usual (and annoying) 50/60 Hz and 150/180 Hz hum
components."

More bollockx.

**** poor design then, if their having those problems.

Mic preamps for audio production are a more stringent
environment than say, RIAA phono preamps. RIAA MM phono
preamps have 40 dB gain at 20Hz, but their noise
bandwidth is only 50 Hz. Mic preamps typically have up
to 60 dB of gain, and a minimum of 20 KHz noise
bandwidth, usually far more.

Arny surely your not saying that they can't design a mic
amp without a built in AC PSU now are you?...


It's not a matter of not being able to design an acceptable preamp with an
internal transformer, its a matter of the ultimate performance of similar
preamps that differ only in the location of the power transformer.




Sounds to me like their passing off the nuisance value of a wall wart
supply as some sort of benefit!.....
--
Tony Sayer

Mains filters
 

"Glenn Richards" wrote in message
...
Iain Churches wrote:

By "cleaning up" I was referring specifically to applying digital
noise reduction. The re-EQ was mentioned simply for completeness,
as the recordings were a bit bass-shy and lacking in sparkle. So a
touch of smiley EQ solves that, followed by noise reduction.
Professionals call this "cosmetic enhancement" :-)) For one's own
use, make any changes that take your fancy. For a commercial release,
I regard the smiley brigade with deep distrust. When the big day
comes and we all standing in line in the big mastering room in the
sky, they will have much to answer for:-)

Depends on how the original sounded, really.


Yes indeed. There is a great deal of butchery that goes on in the name
of "mastering" This is hardly ever the case with classical mastering
or re-issues.

I've been doing some experimentation with comparing non-remastered CDs to
remastered ones, actually after buying the latest ABBA box set (Complete
Studio Recordings) and being shocked at the amount of compression that was
in use.

I always found the original Polydor/Polar CDs rather bass-shy and lacking
sparkle compared to the remasters, but the remasters lacked punch and
dynamics (although the tonal balance was better). So I dug out my original
Polar CDs, ripped them to WAVs and started playing about. Applied a bit of
smiley EQ, and the tonal balance was then the same as the remasters (lost
the excessive midband that the remastering had taken out). On "The
Visitors" (recorded digitally) this was all that was needed, earlier
releases sourced from analogue needed some NR applying as well.

I'm fairly convinced that the Polar CDs were produced from the same 2ch
analogue master as the vinyl versions, the reason being that my vinyl copy
of Super Trouper has exactly the same drop-outs and pre-echo print through
as the Polar CD, in exactly the same places. Indeed, the only real
difference (apart from the slight scratch on the first track and a bit of
surface noise) is that the applause at the end of the final live track
runs through the lead-out groove, until the arm lifts (if you've got a
semi-auto turntable). On the CD it fades out.

I was at RCA at that time. We had the licence for Abba distribution.
There was little if any local mastering. In the case of vinyl, we received
a Mother matrix from Sweden from which stampers were grown.
There were many territories to which vinyl pressings were shipped
in bulk, (probably due to a lack of faith in local production and quality
control)

During the period of the vinly CD overlap, CD submasters were also
supplied. I believe these to have been made from the same originals
from which the analogue lacquer was cut. I must dig out
Super Trouper and make some comparisons. Thanks for raising the
point.

It's rather vital that you EQ before NR though, otherwise the re-EQ
boosts bits that the NR has cut, leading to some interesting
pumping effects...
That's correct. One needs to do a dummy run though to see if the pre-EQ
is the best possible after you have heard the NR.

Yup. Nero Wave Editor has a very useful "undo" function, so if the EQ was
too steep, or not steep enough, you can go back, change it, re-NR, and try
again.

Most large digital workstations have many layers of undo.


Back in the days when I worked part time in a recording studio (when I was
about 15!) this was the stuff that engineers dreamed about, while we
sliced up bits of 1/4" tape with a razor blade. And that was only 13 years
ago!

It takes a stout heart to step up to the multitrack machine
(24tracks on 2 inch) with a splicing block and a razor blade
(no undo function there) mark up with a chinagraph pencil
from a score or leadsheet, and then cut,
while everyone is waiting and watching. We had a policy
of always making composites to that the mix was made
from a complete version on multitrack cut together.

But you can still keep your splicing skills polished working in
digital also. One can razor-blade edit the multitracks made
on a Studer D827 24/24 DASH machine. There is a 2 inch
splicing block fitted into the front plate. It's fun:-))

The digital age has made things much simpler, but there was
much more fun when you had to fly by the seat of your pants,
as they say:-)

So in these instances I do the NR first. Any subsequent gentle EQ
slightly raises the noise floor, but with vintage material is of
little consequence. The secret is to do as little as possible In this
instance less is often more :-)

Yup, likewise on these recordings my aim was to do as little as possible.

The irony is, my remastering attempts using £60 worth of software running
on a Windows XP box of what is now a fairly mid-range spec (AMD XP2800+,
2GB DDR RAM, 120GB HD) actually sound considerably better than what some
muppet at Universal Music with half a million quid's worth of kit and a
fetish for abusing the compressor/limiter could come up with...

Yes indeed. The first audio workstation I used was Lexicon Opus. The
user interface ran under DOS with a green screen monitor. It had removable
hard disks, and cost more than a four bedroomed house!

Iain

Mains filters
 

"tony sayer" wrote in message
...

You asked me to post details of the unit which I had seen.
To meet your request I did this, without an opinion or an
interest eith for or against.

Don't suppose you have;)


Since then I have been able to find out the sales figs for
the Scandi countries. I am told the highest sales within the EU
are to the UK. There is a "huge" mark-up. So someone is making
a pile of cash. From your bitterness, I deduce it is not you:-))


Me bitter?, nah!, wish I was as bent as some people who sell/ supply
these things but I can't bull**** like they do and prey on the gullible.

Do you think that the above statement "filtering the mains to make your
TV picture sharper" to would stand scrutiny with sensible double blind
testing, or even the trades descriptions act?..

Good point. In Finland and Sweden we have a "fitness of goods" act
which is much tighter than the trades descriptions act in the UK. Yet
these units are on sale here too.

Look at it this way Tony. If you are planning to market a product you
first need to find out what consumers (think they) need. If they come
beating a path to your door, asking for mega mains cables at E850
then what do you give them? Yes, you've got it....... It would be
churlish to refuse:-).

People seem to think they want mains filters, and the couple of
phone calls that I made this afternoon convinced me that the demand
is certainly there (particularly in the UK!!) so a smart manufacturer
gives the punters what they (think they) want.

Iain

Mains filters
 

Hi,

"Serge Auckland" wrote in message
...

I think there is a point being missed he- Mains filtering won't
"make the audio sound better"

Agreed.

but it will remove impulsive interference like motor switching spikes
if any are present. If you do an A-B comparison before and after
installing any filtering, you *won't* hear any difference unless just
at the time you were doing the tests, the farmer next door switches
off his milking machine, or the spot-welder at the blacksmith down the
lane goes off.

My point was that my audio kit was happily doing it's thing on one ring
main,
while the electrician systematically turned on and off everything on
another
ring - fridges, chest freezers, sodium lights etc. They are on the same
distribution board. I didn't hear a thing, with or without filtering. No
fizzes,
crackles or pops, and no martians talking out of the left speaker. Maybe
I should thank Audiolab for a decent PSU :-)

BTW, next door does have a milking machine, about 500 yards away.
(really!) Power between here and there is overhead, passing about
15 meters from my house. The nearest GSM mast is 400 yards away
in the same direction. I never hear a thing coming out of my speakers
apart from music. The shed has it's own 10mm2 radial, which helps.

It wasn't always this way - I created a home made disco system
at the age of 15 that was home to several thousand earth loops,
bad grounds, mains hums and noise gremlins. I think I've heard
most of the noises that mains a.c. makes at 50Hz!

Closer to home, fridge compressors and central heating pumps can put
splats on the mains, and whilst I would always suggest suppression at
source, that might not be possible if the offending item is in your
neighbour's house, or the next flat.

Fortunately, my shed is in a big garden, surrounded by farms.
The nearest neighbours are black and white and taste good with
pepper sauce :-)

The avoidance of mains-borne clicks or equipment lock-ups is the main
function of domestic mains filtering. All other suggestions of
improvements in the sound are snake-oil, put about by those selling
expensive filtering items.

We agree. It should be done in the PSU, but if the difference in
price between a four way mains block without sensible filtering
and one that has it is a pound, I'd probably take a minute or two
to choose, because there are some really naff PSUs in the world,
just as there are some really naff mains filters in the world.

Regards,

Glenn.

Mains filters
 

Hi,

"Arny Krueger" wrote in message
. ..
"tony sayer" wrote in message


Arny surely your not saying that they can't design a mic
amp without a built in AC PSU now are you?...


It's not a matter of not being able to design an acceptable preamp with an
internal transformer, its a matter of the ultimate performance of similar
preamps that differ only in the location of the power transformer.

Is that what they mean by "thinking outside the box"?

I'll get my coat.

Regards,

Glenn.

Mains filters
 

"Glenn Richards" wrote in message
...
Rich Wilson wrote:

If you're going to upgrade your power cable you really ought to do it
all the way back to the substation, otherwise it's a bit pointless...

Well that was my initial thought... but apparently not.

In a conversation I had with a friend, we determined that power cables are
good at carrying low frequencies, and poor at carrying higher frequencies.
So RFI picked up at the substation won't make it to your house, but
interference sources in your house will cause RFI to reach your kit.

What I want to know is how exactly the RFI gets through all the smoothing
capacitors and so on in the rectifier. I've got a little headphone amp here
with enough capacitance to not notice, say, a 2-second cutout in its power
supply, so I fail to see how any audible frequency could get through.

Mains filters
 

In article , Glenn Richards wrote:
In a conversation I had with a friend, we determined that power
cables are good at carrying low frequencies, and poor at carrying
higher frequencies. So RFI picked up at the substation won't make
it to your house, but interference sources in your house will cause
RFI to reach your kit.
How do you determine the electrical properties of cables by
conversation?

By applying known principles of engineering.

Applying them to what?

The losses at high frequencies are significantly higher in 2.5mm mains
wiring cable than screened co-ax, if you don't believe me try running a
composite video signal down mains cable (rather than 75ohm co-ax) and
see how far you get.

I think you have unwittingly confirmed that it is not "conversation" that
determines the properties of cables (or anything else), but testing.

It's like saying "how can you determine that an Audi Quattro is going to
go around a hairpin bend at 100mph faster than a Ford Fiesta", for example.

It is indeed, and the answer is the same. No amount of conversation will
determine the abilities of motor cars without some sort of practical test.

Unless you can explain otherwise......

Rod.

Mains filters
 

In article , Glenn Richards wrote:
And if it does make a perceptible difference, however tiny, that means
£50 profit each time...
And when it is discovered that it makes no difference whatsoever...?

*If*, not when. I've yet to start experimenting on these things...
[...]
I've yet to do any thorough testing. When I do, I'm
sure I'll post the results here. It'll be entertaining, if nothing else
- if there isn't a difference I'll have half of you nodding in agreement
and the other half calling me "cloth-eared", if there is a difference
I'll have half of you nodding in agreement and the other half saying
"you must have imagined it".

The best way to avoid this uncertainty is to ensure the tests are carried
out with proper scientific rigour in front of impartial witnesses, and that
full details of the test procedure are published so that anyone so inclined
can check for sources of errors that you may have missed, or even repeat the
tests. Only in these circumstances could there be no arguing with the
results. I look forward to seeing your results.

Rod.

Mains filters
 

In article , Glenn Richards wrote:
I've got all my electrical equipment plugged into the normal wiring
that came with the house, no fancy filters anywhere, nothing special
at all, and have never heard any splats from my loudspeakers since I
stopped listening to AM radio. There's no audible hiss from a normal
listening position either, even if I turn the volume control to its
upper endstop. (Normal listening requires about a quarter turn). My
audio and video equipment is not the sort of silly pretentious stuff
that costs a king's ransom, and it's not cheap rubbish either, just
carefully chosen well-designed gear that works.

Go on then, what kit have you got?

The heart of the audio kit is a Cambridge Audio 540A amplifier, a 640C CD
player and a 640T tuner. Loudspeakers are Bowers and Wilkins DM2s bought
some time in the early 1970s and still sounding so good I've never felt
inclined to replace them. I have Sennheiser HD 560 headphones too.
There's also a NAD tape deck, a Hitachi VHS machine, a Matsui freeview
box, two Panasonic HDD/DVD recorders and a Humax HDD recorder. My laptop
computer normally sits on a nearby shelf so I can feed its audio output
into the system and listen to internet radio, though now that the novelty
has worn off I rarely do. Some of this gear isn't used much so it will
probably eventually go the same way as the Garrard 401 turntable and SME
pickup arm I got rid of about 20 years ago.

The sound is beefy enough for the loudest listening I like to do, and
sweet and clear at low volume for late light listening (or viewing) and
there are no spurious hisses hums or splats under any circumstances.

Rod.