In article , Arny
Krueger
wrote:
"MiNe 109" wrote in message

In article ,

Is this discussion on the right track?:

http://recforums.prosoundweb.com/index.php/m/379726/0/

I think this is the one I have criticized some parts, agreed with others.

Especially the illustration to message #377599.

Not really. That relates to RIAA filtering which is supposed to be
symmetrical with filtering that was added during recording. The two
filters are supposed to cancel out.

The example I can see on the above page shows a clipping event during a
time period from about '27.434' to '27.436'. Annoyingly, I can't see any
expletive units! Wish people would realise 'graphs' don't mean much
without units.

Tired at present so the following is just rough thoughts...

However if the numbers are seconds the duration is just under 2 ms. That is
quite a short time for this to show so much effect from a HPF with a
turnover down at c10Hz.

If so, am therefore wondering if this is something like cutter limiting.
But I'd need to think on it for a while to decide if it is velocity or
what. :-)

If the units are ms, then the duration is just under 2 microsec. That seems
rather too short to make the units ms. :-)

So I am currently wondering about what kind of cutter limit this might be,
but haven't yet decided.

Interesting, though. If Arny hasn't explained it by tomorrow when I check
usenet again I'll do some more puzzling about it. :-)

Slainte,

Jim

--
Change 'noise' to 'jcgl' if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

In article ,
"Arny Krueger" wrote:

"MiNe 109" wrote in message

In article
, "Arny
Krueger" wrote:

"MiNe 109" wrote in message

In article
, "Arny
Krueger" wrote:

"MiNe 109" wrote in
message

In article
, "Arny
Krueger" wrote:

IOW, there's nothing inherently wrong with the CD
medium, even though sometimes people abuse it and
create bad-sounding recordings.

Thanks for the comments. My non-technical
understanding was that cutting heads would round off
those square tops.

That would show up in the leading edge, not the
trailing edge.

Yes, indeed. I don't know what's supposed to happen at
the brick-walled peak.

Leading edge.

Is this discussion on the right track?:

http://recforums.prosoundweb.com/index.php/m/379726/0/

I think this is the one I have criticized some parts,
agreed with others.

Yes, it is. I was interested in the illustration.

Especially the illustration to message #377599.

Not really. That relates to RIAA filtering which is
supposed to be symmetrical with filtering that was added
during recording. The two filters are supposed to cancel
out.

And the square wave reappears?

Ideally, yes.

The practical example of this is what happens when you use an inverse-RIAA
network (standard audio test bench component) to drive a RIAA phono preamp.
If the preamp is very accurate, the square waves that you put in, pretty
well come out of the UUT. Some rounding, and a little tilt in the real
world.

Thanks.

Stephen

In article , David Looser
scribeth thus
"tony sayer" wrote in message
...

As someone who spent many years in domestic TV at that time I can tell
you that 625 line intercarrier buzz was a very big problem for the
majority of UK sets, but never seem to have had any problems with 405
line ones apart from the old line whistle..


As someone else who has spent many years working with domestic TV I have to
say that I entirely disagree with you. You won't, of course, get
*intercarrier* buzz from 405 line sets, the intercarrier was at 3.5MHz (not
many of us can hear that high :-), but vision-on-sound was always a major
problem, plenty of articles about it appeared in "Practical Television". Of
course it competed with other sources of hum and buzz in the sound channel,
such as mains hum and frame buzz, but it was always present. By contrast FM
sound was *potentially* far better, if it hadn't been for the bean counters.
The split inter-carrier system that really only started to appear in
domestic TVs after NICAM arrived could provide an entirely buzz free
performance from FM.

Methinks you are viewing 405-line TV sound through rose-tinted spectacles.

David.


Not really we built a decent amp in a TV we had and that was very good
indeed. Course FM had other advantages but it was surprising how good
the sound could be..

But wasn't .. due to penny pinching in set manufacture..

And we rarely had sound on vision rather the other way round perhaps we
just had different makes predominately Phillips...
--
Tony Sayer

In article , David Looser
scribeth thus
"tony sayer" wrote in message
...
In article , Dave Plowman (News)
scribeth thus

Pretty well every receiver was band limited to remove the 10k line
whistle. Not that many TV sets had speakers that went up that far anyway.


No the built in speakers were usually awful apart from one or two
notable exceptions, but using external amps and speakers it was
champion..
--

Words fail me!

The internal audio amps were also usually awful, but connecting external
amps wasn't easy, not only because of the almost universal live-chassis
arangement, but also because the circuitry around the audio detector/impulse
interference limiter/volume control/audio amp operated at high impedance and
was designed to work as a complete system (and at lowest possible cost).
Connecting additional capacitive or resistive loads would upset the
time-constants and/or load down the limiter. And you'd still have that
vision-on-sound problem.

Well we managed to get around those problems quite easily in later times
we had transistor stages which we easier to adopt. Of course the general
quality of the reproduced sound was in the main quite poor with a few
exceptions..



The transmitted bandwidth was only 10k anyway.

Are you sure about that?..

David.



--
Tony Sayer

"tony sayer" wrote in message
...

Not really we built a decent amp in a TV we had

What make/model was it?

and that was very good
indeed.

Compared to what?

Pre-war and immediate post-war TVs generally had some design attention paid
to getting good sound. TV sound was hailed at the time as being "High
Quality", this meaning "High Quality compared to LW/MW/SW radio or 78s
played with a steel needle". In those days a fairly flat response to 10k was
"HiFi". I'm looking at an advert on the back of "Wireless World" for August
10th 1934 for the RGD model 1202 radiogram. It cost 130gns, a fantastic
price for a radiogram in those days, and it proudly states that the response
is "approx flat from 70 to 10,000 cps"

I've got a couple of pre-war TVs and a high quality Ch1 modulator, and
feeding a good source signal into the modulator the sound quality from both
of them is pretty acceptable, not HiFi of course, but not bad at all. But
switch on the vision carrier as well and modulate that with Test-Card C and
there's your vision-on-sound. And that later point applies to every other
405-line TV I've ever tried, whatever it's vintage.

Course FM had other advantages but it was surprising how good
the sound could be..

But wasn't .. due to penny pinching in set manufacture..

Well indeed, and that applies even more strongly to 625-line TVs

And we rarely had sound on vision

You mean vision-on-sound I assume.

rather the other way round perhaps we
just had different makes predominately Phillips...
--
I'm not sure I entirely follow that rather garbled sentence. But I *think*
it means that you had trouble with intercarrier buzz on Philips 625-line
TVs. What models? I had a Philips G11 for some years and modified it to
provide an audio line out (transformer coupled as the G11 used a mains
bridge rectifier) and the performance of that was really excellent. Yes
there was some buzz, but it was sufficiently far below the normal signal
level as to not be audible in normal use even when the signal was fed via my
Quad 44/405 system to a pair of KEF104s. BTW the tuner portion of the
Philips N1700 VCR was amazingly good. After I did a bit of tweaking to my
N1700 the audio performance of it was as good as most domestic audio
reel-to-reel machines at 3.75 ips with no audible intercarrier buzz at all,
and *streets* ahead of the audio performance of either VHS or Betamax.

David.