Dirty Digital [sic.]
 

In article , Eeyore
wrote:


Phil Allison wrote:

and consisting of an array of ceramic resonators.

THAT's why it sounded so awful !

Are you now claiming that the use of "ceramic resonators" caused you to
hear it "trunkating the tails" of reverb?

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
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Dirty Digital [sic.]
 

Jim Lesurf wrote:
In article , Don
Pearce
wrote:
David Looser wrote:
"Don Pearce" wrote in message
...
If this were a first order filter you could probably hear the
resultant half dB approx. at 10kHz. I think I may be able to do that.
Do you? I'm amazed.


Probably not with music, but I've just tried it with noise, and it is no
problem at all.

That does not mean you can hear the "half dB at 10kHz", since you may well
be hearing the loss of the higher frequencies.

Slainte,

Jim


Quite possible. But I suspect that the difference I hear is closer to 10
than 20.

d

Dirty Digital [sic.]
 

"Dave Plowman (News)" wrote:

Eeyore wrote:
WTF no-one chose a sensible sampling frequency and a half sensible bit
depth is forever beyond me.

20 bit and 60 kHz would have done nicely.

It was designed around the semi-pro video recorders of the day.

Not at all. Both Ampex and 3M had reel-to-reel digital recorders with higher
sampling rates.

Graham

Dirty Digital [sic.]
 

David Looser wrote:

"Eeyore" wrote
Arny Krueger wrote:

The noise floor of a well-made recording is on the order of 75-80 dB.

Have you gone completely MAD ?

I can beat you by easily 50dB.

Do you do all your recording in an anechoic chamber then?

What do you think the noise floor of a competently designed studio is ?

Graham

Dirty Digital [sic.]
 

Jim Lesurf wrote:

Arny Krueger

The noise floor of a well-made recording is on the order of 75-80 dB.
Below that is the noise floor, usually from analog (thermal) sources.
This is many times more than is required to properly dither a proper 16
bit conversion.

I'd be interested in seeing data on the noise performance of studio mics
and preamps, etc.

Neumann TLM103. Equivalent noise floor of 7dBA
http://www.neumann.com/?lang=en&id=c...id=tlm103_data
Dynamic range of the microphone amplifier (A-weighted) 131 dB

Graham

Dirty Digital [sic.]
 

Eeyore wrote:

David Looser wrote:

"Eeyore" wrote
Arny Krueger wrote:

The noise floor of a well-made recording is on the order of 75-80 dB.
Have you gone completely MAD ?

I can beat you by easily 50dB.
Do you do all your recording in an anechoic chamber then?

What do you think the noise floor of a competently designed studio is ?

Graham


I think Arny meant S/N ratio rather than noise floor. A decent studio
will be somewhere around the 20dB mark. It is the exceptional studio
that is much below that, and you won't find it in a city.

d

Dirty Digital [sic.]
 

"Dave Plowman (News)" wrote in
message
In article ,
Eeyore wrote:
Yup. Anything that starts off life at a microphone is
unlikely to do very much better. And most recordings
use several microphones...

Really good microphones have equivalent acoustic noise
levels of well below 20 dB.

There's rather more to the average chain than just the
microphone.

Based on my experiences with live recording in several dozen different
venues, the microphones, even those with noise in the 18 to 20 dB range,
are usually quieter than the venue by quite a bit. If it wasn't for the
venues and the performers, recodrings with dynamic range of up to 90 dB
would be pretty common.

Dirty Digital [sic.]
 

"Eeyore" wrote in
message
"Dave Plowman (News)" wrote:

Eeyore wrote:

Someone else (edited out) wrote.

Yup. Anything that starts off life at a microphone is
unlikely to do very much better. And most recordings
use several microphones...

Really good microphones have equivalent acoustic noise
levels of well below 20 dB.

There's rather more to the average chain than just the
microphone.

Please elaborate with especial regard to where you think
my figures are wrong.

That will be herd, because Graham you are correct.

Mic preamps that will not materially add to the noise of a mic with EIN on
the order of 20 dB are pretty common. Digitizing the output of a mic preamp
without adding additional noise does not require costly converters any more.

Dirty Digital [sic.]
 

"Eeyore" wrote in
message
Arny Krueger wrote:

The earliest CD players had converters good enough to
demonstrate dynamic range on the order of 93 dB, which
is pretty close to the theoretical max:

Oh come on !

The earliest CD players were utter ****E. Esp the
CDP-101. Truncated reverb tails is what I remember
especially.

http://www.pcavtech.com/play-rec/Sony_CDP-101/index.htm

shows that a properly-operating CDP 101 does not have serious issues with
dynamic range.

However, the DACs in the CDP 101 had a possible failure mode that might
explain what you heard.

A CDP101 contained 1 rather fast, rather precise 8 bit DAC. It is pretty
well known that the DAC was time-shared between the L and R channels. What
is not so well known is the fact that the DAC did 2 conversions per 16 bit
sample. If memorys serves, the first time period, the high order 8 bits were
converted to analog and gated into an integrator. During the second time
period, the low order 8 bits bits were converted to analog and gated into
the same integrator, but this time the voltage was divided by 256.

The voltage that was read out of the integrator was the sum of the two
conversions, but the second conversion was scaled by 256. The integrator
was then zeroed out. The same two conversions were done with data from the
other channel.

If memory does not serve, I have the order the conversions reversed. ;-)

BTE, this means that the LSB of the 8 bit DAC was really very precise for
being an 8 bit DAC. The division by 256 also needed to be very precise. I'm
under the impression that this slightly odd methodology was frequently used
in the early days of digital audio.

Any errors in setting the division by 256 would cause significant
nonlinearity.

Dirty Digital [sic.]
 

"Dave Plowman (News)" wrote in
message

In article ,
Eeyore wrote:

The earliest CD players were utter ****E. Esp the
CDP-101. Truncated reverb tails is what I remember
especially.

You mean fading out the track early in the CD mastering
to try and stop you hearing the tape hiss?

I have two functional CDP101s at my disposal. If

http://www.pcavtech.com/play-rec/Sony_CDP-101/index.htm

doesn't convince, I might be convinced to do some fade-to-zero tests. The
CDP 101 is not at its best playing CD-Rs, but at least one of the two does
well enough if I do the burning at a low speed.