RE: [neonixie-l] OT: audio levels

2019-04-17 Thread johnk
Thank you so much for playing the game Tomasz, and bothering to check the 
calculations.

It can also be done with DC a meter or scope that shows True RMS when DC is 
present. [Check by reading a battery on the AC range.]

You can set up a sine wave that is offset by a DC value. You make a voltage 
waveform that is the same shape as the power waveform that we are talking 
about. Then you measure it.

 

There is a useful electronics website.

https://masteringelectronicsdesign.com/how-to-derive-the-rms-value-of-a-sine-wave-with-a-dc-offset/

On that page he shows the mathematics involved. Notice that a very simple 
formula right at the end/bottom covers what we are doing.

It gives an answer very close to yours too.

 

Regarding audio and perceived loudness: if you ever want to increase that 
impact of the sound without “cheating” by using a compressor, then just record 
to magnetic tape. You could even use a deck that has replay monitor heads 
immediately after the record heads so that it is close to real time.

To get up out of the noise they had to set up magnetic to work in a rather 
non-linear region. It automatically compressed. This was one of the things that 
made full digital audio sound different. They didn’t set out to compress “old” 
audio but it happened anyway.

 

That consistent loudness thing really annoys me too. Unfortunately some of the 
normalising programs cause other problems. Some of the problem is caused by 
people using the scope view in their digital software. When you have 20dB 
headroom it looks like you are working so far down that you must be in the 
noise. They also think that you are wasting that space. This is where metering 
methods become so important too. And some training/awareness.

 

Thanks to all the Nixie guys for tolerating this OT discussion too.

Regards,

John K

 

From: neonixie-l@googlegroups.com [mailto:neonixie-l@googlegroups.com] On 
Behalf Of Tomasz Kowalczyk
Sent: Thursday, 18 April 2019 04:04
To: neonixie-l
Subject: Re: [neonixie-l] OT: audio levels

 



W dniu wtorek, 16 kwietnia 2019 15:57:35 UTC+2 użytkownik johnk napisał:

Well, how do I say this Thomas?

It is NOT to be called Watts RMS !

They left the vital word out – it is Watts [RMS derived]. They left out 
“derived”.

 

The RMS volts and RMS amps that you mention when multiplied together produce 
Watts. Just plain Watts.

These Watts are actually the average power of the power waveform that resulted 
from your two sinewaves.

Remember too, that the RMS value of the voltage waveform gives the DC voltage 
that provides the same heating effect. And that is average power.

Gee, I didn’t say that well. I have just spent a while fighting with Win 10 and 
drivers for CH340 on Arduino clone boards – I haven’t recovered !

 

You might think that I am nit picking. However you did say this, “RMS power of 
a sine wave is 0,5 times peak power.”

And the power waveform isn’t really a sinewave in the way we mean it. The 
values of interest here lie in the area under the curve (notice it is twice the 
frequency too?]. In a sine wave [like the Voltage one]  the areas of interest 
are the equal sized ‘lobes’ above and below the zero line. 

I invite you to draw out the two sinewaves [Volts and Current] and the 
resulting power waveform and perform an actual root-mean-square calculation on 
it to prove your statement.  [Graphically is more reliable because it shows the 
workings J  ]

Spoiler: you will NOT get 0.5 x pk as the answer.

 

The VERY rough sketch that I sent Charles shows what I mean about the average 
value [the green bit tipped over into the trough].

(Rough because I was on a new touch screen laptop and NOT in tablet mode. I was 
experimenting; made it tricky to draw with the pen. )

 

I know that you know what you mean when you refer to amplifiers this way, but 
you could add the extra word and be ‘more right’  J

Thanks for nibbling on the hook. But, I really do wish that someone had been 
willing to do the graphical maths thing. Someone must want to prove me wrong, 
surely.

 

John Kaesehagen

Australia

 

 

OK, I see your point. The right way to spell power is just watts (V RMS * I RMS 
= W)
I've ran a little excel excercise - I calculated voltage and current with peak 
value equal to sqrt(2) for 360 points of a sine wave. If I run RMS calculation 
(from definition) on voltage or current, it is equal to 1 (so one times the 
other is 1W), but running it on voltage*current gives a value of about 1,22W 
RMS. 
I admit this is a mistake to use W RMS.

 

When it comes to Loudness War - I am also for dynamic range, but mostly, I am 
for consistent loudness between digital files, so I don't have to change volume 
for each track. Fortunately, loudness war is being actively fought against - as 
far as I know, Spotify attenuates a track if it is too loud, which eliminates 
the whole reason songs were overcompressed. So now those tracks are left with 
their poor dynamic range, but being

Re: [neonixie-l] OT: audio levels

2019-04-17 Thread Tomasz Kowalczyk


W dniu wtorek, 16 kwietnia 2019 15:57:35 UTC+2 użytkownik johnk napisał:
>
> Well, how do I say this Thomas?
>
> It is NOT to be called Watts RMS !
>
> They left the vital word out – it is Watts [RMS derived]. They left out 
> “derived”.
>
>  
>
> The RMS volts and RMS amps that you mention when multiplied together 
> produce Watts. Just plain Watts.
>
> These Watts are actually the average power of the power waveform that 
> resulted from your two sinewaves.
>
> Remember too, that the RMS value of the voltage waveform gives the DC 
> voltage that provides the same heating effect. And that is average power.
>
> Gee, I didn’t say that well. I have just spent a while fighting with Win 
> 10 and drivers for CH340 on Arduino clone boards – I haven’t recovered !
>
>  
>
> You might think that I am nit picking. However you did say this, “RMS 
> power of a sine wave is 0,5 times peak power.”
>
> And the power waveform isn’t really a sinewave in the way we mean it. The 
> values of interest here lie in the area under the curve (notice it is twice 
> the frequency too?]. In a sine wave [like the Voltage one]  the areas of 
> interest are the equal sized ‘lobes’ above and below the zero line. 
>
> I invite you to draw out the two sinewaves [Volts and Current] and the 
> resulting power waveform and perform an actual root-mean-square calculation 
> on it to prove your statement.  [Graphically is more reliable because it 
> shows the workings J  ]
>
> Spoiler: you will NOT get 0.5 x pk as the answer.
>
>  
>
> The VERY rough sketch that I sent Charles shows what I mean about the 
> average value [the green bit tipped over into the trough].
>
> (Rough because I was on a new touch screen laptop and NOT in tablet mode. 
> I was experimenting; made it tricky to draw with the pen. )
>
>  
>
> I know that you know what you mean when you refer to amplifiers this way, 
> but you could add the extra word and be ‘more right’  J
>
> Thanks for nibbling on the hook. But, I really do wish that someone had 
> been willing to do the graphical maths thing. Someone must want to prove me 
> wrong, surely.
>
>  
>
> John Kaesehagen
>
> Australia
>
>  
>
>  
>
OK, I see your point. The right way to spell power is just watts (V RMS * I 
RMS = W)
I've ran a little excel excercise - I calculated voltage and current with 
peak value equal to sqrt(2) for 360 points of a sine wave. If I run RMS 
calculation (from definition) on voltage or current, it is equal to 1 (so 
one times the other is 1W), but running it on voltage*current gives a value 
of about 1,22W RMS. 
I admit this is a mistake to use W RMS.

When it comes to Loudness War - I am also for dynamic range, but mostly, I 
am for consistent loudness between digital files, so I don't have to change 
volume for each track. Fortunately, loudness war is being actively fought 
against - as far as I know, Spotify attenuates a track if it is too loud, 
which eliminates the whole reason songs were overcompressed. So now those 
tracks are left with their poor dynamic range, but being no louder than 
slightly compressed or not compressed at all songs.
I'm currently building a vacuum tube amplifier, which works greatly with 
uncompressed tracks - it compresses them itself via soft clipping! That's 
the reason 15-20W tube amp can sound like 50W solid state, vocals and most 
instruments can stay at the same SPL, but vacuum tube amp will compress the 
short spikes from percussion or other instrument instead of grossly 
distorting them. Solid state needs that power headroom to prevent going 
into clipping, because you can easily hear it and it isn't pleasurable.
Of course, I could also just build a simple Gainclone amp with higher 
output power for more headroom... but high voltage is fun!

Coming back on topic of audio signal level - I think that if I worked in 
proffesional audio, all the different standards would make more sense to 
me. But being a hobbyist who just wants to build an amp, it is straight up 
annoying.

By the way - you can keep calling me Thomas. It is practically the same 
name. Also when I was a kid I used to live in USA for over a year, so I was 
called Thomas a lot in my life :) 

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/029027cb-4ef1-47cd-b915-cdbaf837f5ca%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.


RE: [neonixie-l] OT: audio levels

2019-04-16 Thread johnk
Thomas, the audio levels standards do exist. But I agree with you that there 
isn’t just one.

Each of the areas has its own standard. So, you do have a known standard for 
consumer electronics. You do have  known standards for radio/entertainment, 
studio and professional work [pre DAWs]. And you do have a ‘new’ standard for 
recent era digital equipments. That is why I mentioned Bob Katz’ book when Jens 
asked his question. I had to work with a Dutch mixing desk that attempted to be 
able to be employed in ‘both’ eras radio and recording studio environments. 
They didn’t manage it – they threw away a lot of head room. [Scorpius] The 
metering issues created extra problems because ideally you want the standards 
there to match the sensitivities too – but there is conflict. And it all 
depends whether you back the Loudness Wars. Remember too, generally you aren’t 
trying to make an equipment that is to serve in  more than one of the 
environments.

I say – Long Live Dynamic Range !

John Kaesehagen

Australia

 

From: neonixie-l@googlegroups.com [mailto:neonixie-l@googlegroups.com] On 
Behalf Of Tomasz Kowalczyk
Sent: Tuesday, 16 April 2019 19:54
To: neonixie-l
Subject: Re: [neonixie-l] OT: audio levels

 



W dniu piątek, 29 marca 2019 08:46:37 UTC+1 użytkownik charles napisał:

On 2019-03-28 10:09 p.m., johnk wrote: 
 based on teh RMS output (.707 of the peak)

 

That would be 0,707 (1/sqrt(2)) voltage output on a resistive load. RMS power 
of a sine wave is 0,5 times peak power.
I like to know maximum constant RMS output, because it tells me a lot about the 
amplifier and its capability. The peak power or music power usually lacks a 
definition (I can easily imagine a design that would allow for short pulse of 
higher power, but power supply/amplifier would fry up if it was to deliver this 
peak power for longer time).
It is well known that for most time amplifier delivers a little percentage of 
its maximum power, but having continous Watts RMS into specified load rating is 
a very solid rating with solid definition.

On the topic: it really bothers me that there is no definition of one voltage 
standard. It would make perfect sense to create a standard of a CD output, for 
example - a 2Vpp signal, in which +1V would correspond to maximum digital value 
DAC can give (65535 for standard 16-bit) and -1V would correspond to a value of 
0. It would make designing amplifiers much easier - the sensivity would be 
always same. 
Currently I'm building a vacuum tube amplifier and I'm mad at the fact that I 
need to make the sensivity on 200mVpp level (my phone output), but most of 
other sources will have much higher signal. I think I'll need to go with a 
noisy method of applying extra resistor in series with volume potentiometer for 
the higher inputs... or apply the resistor and a "+20dB" switch that will short 
it. 
At least it is a vacuum tube amplifier, so noise will be an issue anyway.

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/6418d010-db45-4c62-8f64-12bdc99a5520%40googlegroups.com
 
<https://groups.google.com/d/msgid/neonixie-l/6418d010-db45-4c62-8f64-12bdc99a5520%40googlegroups.com?utm_medium=email_source=footer>
 .
For more options, visit https://groups.google.com/d/optout.

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/002701d4f45e%24a66d4870%24f347d950%24%40internode.on.net.
For more options, visit https://groups.google.com/d/optout.


Re: [neonixie-l] OT: audio levels

2019-04-16 Thread Tomasz Kowalczyk


W dniu piątek, 29 marca 2019 08:46:37 UTC+1 użytkownik charles napisał:
>
> On 2019-03-28 10:09 p.m., johnk wrote: 
>
> the FTC in the States started cracking down and said that any power 
> claims had to be based on teh RMS output (.707 of the peak) using a sine 
> wave with Specified distortion. AND that the unit had to be conditioned 
> at almost maximum power (75% if I recall, or Perhaps 90%)for several 
> minutes before taking the measurement.  SOME units sudenly could not 
> show ANY power as the pre-conditioning was enough to cause them to shut 
> down or Melt down. 
>
 
That would be 0,707 (1/sqrt(2)) voltage output on a resistive load. RMS 
power of a sine wave is 0,5 times peak power.
I like to know maximum constant RMS output, because it tells me a lot about 
the amplifier and its capability. The peak power or "music power usually" 
lacks a definition (I can easily imagine a design that would allow for 
short pulse of higher power, but power supply/amplifier would fry up if it 
was to deliver this peak power for longer time).
I like that FTC definition requiring amplifier to work with high output 
power before taking a measurement, which is watts RMS. 

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/7c2c3bfe-e43d-4701-86c9-f9ecb39e735a%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.


Re: [neonixie-l] OT: audio levels

2019-04-16 Thread Tomasz Kowalczyk


W dniu piątek, 29 marca 2019 08:46:37 UTC+1 użytkownik charles napisał:
>
> On 2019-03-28 10:09 p.m., johnk wrote: 
>  based on teh RMS output (.707 of the peak)
>

That would be 0,707 (1/sqrt(2)) voltage output on a resistive load. RMS 
power of a sine wave is 0,5 times peak power.
I like to know maximum constant RMS output, because it tells me a lot about 
the amplifier and its capability. The peak power or music power usually 
lacks a definition (I can easily imagine a design that would allow for 
short pulse of higher power, but power supply/amplifier would fry up if it 
was to deliver this peak power for longer time).
It is well known that for most time amplifier delivers a little percentage 
of its maximum power, but having continous Watts RMS into specified load 
rating is a very solid rating with solid definition.

On the topic: it really bothers me that there is no definition of one 
voltage standard. It would make perfect sense to create a standard of a CD 
output, for example - a 2Vpp signal, in which +1V would correspond to 
maximum digital value DAC can give (65535 for standard 16-bit) and -1V 
would correspond to a value of 0. It would make designing amplifiers much 
easier - the sensivity would be always same. 
Currently I'm building a vacuum tube amplifier and I'm mad at the fact that 
I need to make the sensivity on 200mVpp level (my phone output), but most 
of other sources will have much higher signal. I think I'll need to go with 
a noisy method of applying extra resistor in series with volume 
potentiometer for the higher inputs... or apply the resistor and a "+20dB" 
switch that will short it. 
At least it is a vacuum tube amplifier, so noise will be an issue anyway.

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/6418d010-db45-4c62-8f64-12bdc99a5520%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.


Re: [neonixie-l] OT: audio levels

2019-03-29 Thread Charles MacDonald

On 2019-03-28 10:09 p.m., johnk wrote:


An aside: now that we are talking audio, I would love to get an argument going 
about Watts RMS !
I say this:  the watts specified for an amplifier output are intended to be 
average power and not rms power.



Any takers?


I do recall that the merchants is North America got into a bit of a 
"Horsepower Race" with Power ratings on consumer audio equipment.


rather than accept a low number the marketing engineers, started doing 
things like testing with Pulse inputs to use the electrical capacity of 
the Filter caps.  even further some only tested One channel, (so the 
power supply was idling on the other.) or connecting a big lab supply as 
Music is different than sine waves. You started seeing Peak Music Power 
ratings.


the FTC in the States started cracking down and said that any power 
claims had to be based on teh RMS output (.707 of the peak) using a sine 
wave with Specified distortion. AND that the unit had to be conditioned 
at almost maximum power (75% if I recall, or Perhaps 90%)for several 
minutes before taking the measurement.  SOME units sudenly could not 
show ANY power as the pre-conditioning was enough to cause them to shut 
down or Melt down.


I recall seeing a sears catalogue (here in Canada) which showed a 100W 
stereo, with a small text box titled Truth in Audio stating the the unit 
was good for 2W under the US FTC method.


So we can blame the US for inventing "RMS Power" - although they were 
really trying to do the right thing.


--
Charles MacDonald Stittsville Ontario
cm...@zeusprune.ca  Just Beyond the Fringe
No Microsoft Products were used in sending this e-mail.

--
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/550f8703-35f2-4cdf-efb3-8773b3b358f9%40zeusprune.ca.
For more options, visit https://groups.google.com/d/optout.


RE: [neonixie-l] OT: audio levels

2019-03-28 Thread johnk
Jens, I wasn't sure what you intended. Might have been Russian "thermometer" 
tubes as display even.
I wonder what the various guys who have mentioned making audio meters ended up 
doing?

Even though you want it for a headphone level indicator, it might get used by 
others for different purposes.
The problem with any averaging meter in today's audio environment is the fact 
that digital systems clip when overdriven. 
I mentioned tape recording [analogue] earlier. Tape has a natural compression 
effect [I said limiter last time]. It was the lack of realisation of this that 
caused so much of the argument when digital workstations and digital storage 
arrived. The tape recording produced more punch because they couldn't afford to 
operate down in the linear region. [Signal/noise].

A VU meter needs an audio system with 14 to 18dB headroom. Because the meter is 
slow it does not indicate peaks. Taking voice intelligibility into account 
[some clipping allowed], voice peaks are generally 4 to 14dB above what is 
indicated.
A PPM can be used simply - "don't go into the red". The zero [ie start of red 
section] indicates that clipping is occurring. As I mentioned before 0dBFS 
should be a little down from the red [big topic]. FS means Full scale in the 
digital arena - the biggest number that can be represented by your 16 or 24 
bits (or whatever).

For your headphone use you could make the red zone be the onset of distortion 
caused by the headphones overdriving OR it could represent the max safe 
listening level [assuming you don't have level limited phones already].

Sound card specs used to give good levels info. I just looked at my motherboard 
handbooks from the last 15 years and they have zilch.
I am mentioning all of this because if you go to the trouble of coding 
something then you have the opportunity to build in features.
Another reason for going a bit overboard is this: I believe that when shortcuts 
and liberties are taken with standards it should be with the knowledge of what 
has been done. It should be decision based - not a result of ignorance. 

I am a bit wary of pointing to a wiki article, but you have probably already 
been there
https://en.wikipedia.org/wiki/Line_level



An aside: now that we are talking audio, I would love to get an argument going 
about Watts RMS !
I say this:  the watts specified for an amplifier output are intended to be 
average power and not rms power.
When Watts rms is stated it is NOT intended to be read as that. It is intended 
to mean "Watts [rms derived"]. There is a lot of difference.

Any takers?

I invite sceptics to do the math or draw a sinewave power waveform and inspect 
it carefully. Try 1V rms and 1A rms sine wave resistive.
Having looked at it and tipped the top half into the trough [proving what I 
proposed], go ahead and perform an rms calculation on that power waveform. You 
might be surprised.

If that didn't get your attention, look at it his way. Even the respected name 
companies use the W RMS term. So, how can I be right? 

John K
Australia

-Original Message-
From: neonixie-l@googlegroups.com [mailto:neonixie-l@googlegroups.com] On 
Behalf Of jb-electronics
Sent: Friday, 29 March 2019 03:09
To: neonixie-l@googlegroups.com
Subject: Re: [neonixie-l] OT: audio levels

Hi David, hi John,

Thank you very much for your help! I am not trying to build a professional VU 
meter; rather, what I want is to create a microcontroller-based LM3916 
alternative. These are now obsolete LED bar driver ICs with a logarithmic 
output that are quite handy for building a simple (not professional) VU meter.

Lots of things to read for me!

Best wishes
Jens

On 2019-03-28 8:10 a.m., johnk wrote:
> Hey Jens...
>
> 1). Don't call it VU unless you match the actual ballistics of the 
> ORIGINAL VU meter
>
> 2). Europe tends to use a PPM [quasi-peak] system.  Peak Program Meter.
>
> 3). Consumer and pro levels are very different. They are often misunderstood 
> and hence mounds of garbage appear on the web.
>
> 4). dB is a ratio and a reference must be stated. Thus you must choose what 
> reference your 0VU is.
>
> 5). Your headphone out MIGHT be the Line Out. There are [quite a few] 
> standards for Line Level.
>
> 6]. A useful fact relates to the maximum level that can be digitally encoded. 
> A CD can produce a certain maximum digital value. That gets converted to some 
> analogue value. You can work empirically by using [say] standard test tones 
> from the web OR an audio program like Audacity to produce known digital 
> levels.   0 dBFS is the max level... BUT there can be output results higher 
> than this [long topic], so work on using either -0.3dB or even -3dB below (or 
> do I mean over?  Semantics ) this as maximum.
>
> 7). In "recent" years the "loudness wars" and misuse of Digital Audio 
> Workstations has result

Re: [neonixie-l] OT: audio levels

2019-03-28 Thread jb-electronics
(strength or amplitude) of the audio signal 
from mixers, signal-processing equipment and other consumer and professional audio gear. 
There are two line level types: consumer and professional. Consumer line level is 
generally thought of as a signal whose level is at -10 dBV (0.316). CD players and DVD 
players are examples of consumer line level equipment. Professional line level is 
generally thought of as a signal whose level is at +4 dBu (1.23 volts or significantly 
higher). Signal-processing equipment and professional mixing consoles are examples of 
professional line level equipment."


Done quickly, apologies for errors and omissions,
John Kaesehagen
Australia



-Original Message-
From: neonixie-l@googlegroups.com [mailto:neonixie-l@googlegroups.com] On 
Behalf Of jb-electronics
Sent: Thursday, 28 March 2019 11:42
To: neonixie-l@googlegroups.com
Subject: [neonixie-l] OT: audio levels

Hello Nixie friends,

I am thinking of building a simple all-in-one VU meter using a microcontroller 
to visualize the audio signal on a headphone line (say, I feed the headphone 
output of my PC to my circuit, and then I install a pass-thru to connect to my 
headphones).

What is the typical voltage amplitude I should expect? I do realize this 
question is quite general, but perhaps you can point me in the right direction? 
Many thanks!

Best wishes
Jens

--
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/2a4dfbef-7430-06ac-b272-973d84c6dae8%40jb-electronics.de.
For more options, visit https://groups.google.com/d/optout.



--
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/7085f76d-a412-7fad-ba76-9858ede4cd02%40jb-electronics.de.
For more options, visit https://groups.google.com/d/optout.


RE: [neonixie-l] OT: audio levels

2019-03-28 Thread johnk
f 
as a signal whose level is at +4 dBu (1.23 volts or significantly higher). 
Signal-processing equipment and professional mixing consoles are examples of 
professional line level equipment."


Done quickly, apologies for errors and omissions,
John Kaesehagen
Australia



-Original Message-
From: neonixie-l@googlegroups.com [mailto:neonixie-l@googlegroups.com] On 
Behalf Of jb-electronics
Sent: Thursday, 28 March 2019 11:42
To: neonixie-l@googlegroups.com
Subject: [neonixie-l] OT: audio levels

Hello Nixie friends,

I am thinking of building a simple all-in-one VU meter using a microcontroller 
to visualize the audio signal on a headphone line (say, I feed the headphone 
output of my PC to my circuit, and then I install a pass-thru to connect to my 
headphones).

What is the typical voltage amplitude I should expect? I do realize this 
question is quite general, but perhaps you can point me in the right direction? 
Many thanks!

Best wishes
Jens

--
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/2a4dfbef-7430-06ac-b272-973d84c6dae8%40jb-electronics.de.
For more options, visit https://groups.google.com/d/optout.

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/000801d4e56f%24f21ca0c0%24d655e240%24%40internode.on.net.
For more options, visit https://groups.google.com/d/optout.


Re: [neonixie-l] OT: audio levels

2019-03-27 Thread David Forbes
Expect 0.1 to 1V peak-peak, depending on volume.

On Wed, Mar 27, 2019, 6:11 PM jb-electronics 
wrote:

> Hello Nixie friends,
>
> I am thinking of building a simple all-in-one VU meter using a
> microcontroller to visualize the audio signal on a headphone line (say,
> I feed the headphone output of my PC to my circuit, and then I install a
> pass-thru to connect to my headphones).
>
> What is the typical voltage amplitude I should expect? I do realize this
> question is quite general, but perhaps you can point me in the right
> direction? Many thanks!
>
> Best wishes
> Jens
>
> --
> You received this message because you are subscribed to the Google Groups
> "neonixie-l" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to neonixie-l+unsubscr...@googlegroups.com.
> To post to this group, send an email to neonixie-l@googlegroups.com.
> To view this discussion on the web, visit
> https://groups.google.com/d/msgid/neonixie-l/2a4dfbef-7430-06ac-b272-973d84c6dae8%40jb-electronics.de
> .
> For more options, visit https://groups.google.com/d/optout.
>

-- 
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/CAPbqtvcyTUXxgdbCJeB9ZqVCoJoovPUKTkaapxNtszp1TMqYkw%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.


[neonixie-l] OT: audio levels

2019-03-27 Thread jb-electronics

Hello Nixie friends,

I am thinking of building a simple all-in-one VU meter using a 
microcontroller to visualize the audio signal on a headphone line (say, 
I feed the headphone output of my PC to my circuit, and then I install a 
pass-thru to connect to my headphones).


What is the typical voltage amplitude I should expect? I do realize this 
question is quite general, but perhaps you can point me in the right 
direction? Many thanks!


Best wishes
Jens

--
You received this message because you are subscribed to the Google Groups 
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit 
https://groups.google.com/d/msgid/neonixie-l/2a4dfbef-7430-06ac-b272-973d84c6dae8%40jb-electronics.de.
For more options, visit https://groups.google.com/d/optout.