Ethan Winer Builds a Wire Null Tester

[pkane]

Somebody already mentioned the digital cassettes. Commodore had them as well as big mainframes with reel tape at one time. There were/are the phone modems. You can listen to those, but they are digital in nature transmitting digital information. Then there were keypunch cards and paper tape.

As for Diffmaker, it can do amazing things, and about as often fail and more often simply blow up. Now when it is amazing it takes two files that aren't digitally synched, adjusts for sample rate differences and then for sample rate drift. Then gives a nice deep null. In the course of doing that it will blow up nearly half the time. Heck I tried a file in it yesterday which was consecutive runs where nothing changed. It was a loopback so no synching issues involved. Manually there were nulls of about -106 db. Diffmaker said correlation null of 14 db. Nothing weird about the file.

@pkane is working on a similar bit of software. So maybe he'll get it finished and we can get reliable results more often than with Diffmaker.

When you get to deep nulling it takes so little to corrupt it. I'll sometimes embed two tones an octave apart. If you null them and the null residual is 6 db higher for the higher frequency tone you know the bulk of the residual is a time shift.

The reason I started work on DeltaWave was that AudioDiffMaker was so unpredictable. Sometimes it worked, sometimes it crashed, and sometimes the result seemed completely wrong.

While DeltaWave is far from commercial quality software, it's close enough to be usable by 'knowledgeable' enthusiasts, so I'll try to get a beta version of it out in the next couple of weeks. Just need to free up some time between work and family obligations to package it up

 

[danadam]

I think it's a matter of definition when a signal is called analog or digital ?
The fact that both are bandwidth limited electrical signals says nothing about its nature (analog audio or digital audio).

I'm always confused why people are confused about it The definition seem straightforward (from wikipedia):

An analog signal is any continuous signal for which the time-varying feature (variable) of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal. For example, in an analog audio signal, the instantaneous voltage of the signal varies continuously with the pressure of the sound waves.

So electrical representation of digital signal is not an analog signal because it is not analogous to anything.

 

[Blumlein 88]

I'm always confused why people are confused about it The definition seem straightforward (from wikipedia):

So electrical representation of digital signal is not an analog signal because it is not analogous to anything.

Just wanted to quote so I could see it on here twice.

 

[andreasmaaan]

I'm always confused why people are confused about it The definition seem straightforward (from wikipedia):

So electrical representation of digital signal is not an analog signal because it is not analogous to anything.

Thank-you. I'd never thought about it before as nothing actually turns on it, but this simple definition wins the debate methinks

 

[Soniclife]

It reminds me of my first PC, a Sinclair. It got its data from a tape cassette, making noises as I downloaded a program into memory. Those noises made a great impression back then.

Jump to about 5:45.

The CD has the TOC configured perfectly so that the data burst which is the file header info is perfectly synced to the start of the next track, on the right CD player or app it's like the track number has been loaded from the file.

 

[Deleted member 65]

Interesting what studies say this?

No study says this.

If you're a "Somewhere" certain things make you happy such as family, religion, countryside, safety, traditions, nations aso on the other hand if you're an "Anywhere" other things such as individualism, performance, academic degrees, free trade, open borders, modernity, cosmopolitan, change aso matters.

What we're seeing now is that the "Somewhere's" are reacting to the "Anywhere's", guess who voted for Brexit, Trump, Bolsonaro et al.

Recommend a read of this book "The Road to Somwhere" by
David Goodhart

 

[Soniclife]

Have you ever listened to a digital signal. I mean plug the SPDIF out of a source directly into an analog input and listened to it ?
Did you hear music from this 'analog' source (no cheating by using a DAC) ?

A friend used to have a CD transport and DAC combo that would play any CD as audio, Windows 2000 had a better beat than office.

I once recorded a spectrum game from BBC4 FM radio, that must have confused some listeners.

 

[solderdude]

I'm always confused why people are confused about it The definition seem straightforward (from wikipedia):

So electrical representation of digital signal is not an analog signal because it is not analogous to anything.

That's my reasoning too, but some feel that any signal and electrical waveform is 'analog' in nature. Not me though. There are distinct differences between a digital and analog signals.

 

[DonH56]

Semantics. I was talking about the signal itself since that is my world, not what you/they call "the electrical representation".

Oddly, I did very well in my digital courses in college, and was the first undergraduate TA for the advanced digital circuits lab at my college, but went the analog way in the end.

In any event I like Ethan and his null test.

 

[mansr]

A friend used to have a CD transport and DAC combo that would play any CD as audio

Any pre-CDROM player will do this.

 

[restorer-john]

It reminds me of my first PC, a Sinclair. It got its data from a tape cassette, making noises as I downloaded a program into memory. Those noises made a great impression back then.

I swapped a kid at school my Coleco Vision TV game for his Sinclair ZX-81, as I'd been wanting a 'real' Z-80 based computer instead of just development boards. I got the 'massive' 16K extension pack in the swap too.

Somewhere, deep in a shoebox, is an I/O header and interface PCB, I built for the Sinclair and we used it to initially drive a Tasman Turtle my best friend and I built for a Science Competition (we came second). We wanted an untethered self contained plotter/explorer and my Sinclair was pretty much the only single board computer with enough grunt (or so we thought).

I built the Robot, he did the programming. Battery life was too short running the turtle and the computer. The Sinclair crashed everytime the robot's stepper motors pulled current. More NiCads meant the turtle tore up the paper and wouldn't move accurately.

So at the last minute we used one of the school's Apple II clones, ran it from the computer power and he re-wrote the software the night before. It all worked on its rainbow umbilical lead, drawing on butchers paper on the biology lab floor.

He went on to make an absolute fortune in the earliest days of the internet.

 

[Soniclife]

I got the 'massive' 16K extension pack in the swap too.

RAM pack wobble could end a gaming session if it happened. They got really hot as I remember.

I'm still amazed 3d monster maze ran in 1k of ram.

 

[restorer-john]

They got really hot as I remember.

They did get really hot, I'd forgotten that. There was a reasonable piece of aluminium flag heatsink on the 7805 regulator but no airflow. The ram pack was a nightmare and got hot too. When it made intermittent connection, the computer just locked up- always before you had saved all your hard work to cassette...

 

[Soniclife]

They did get really hot, I'd forgotten that. There was a reasonable piece of aluminium flag heatsink on the 7805 regulator but no airflow. The ram pack was a nightmare and got hot too. When it made intermittent connection, the computer just locked up- always before you had saved all your hard work to cassette...

There was also the truly weird fast mode, which broke the TV sync and you would have to adjust the vertical hold to make it work.

I learnt almost everything I know about programming from reading the manual from cover to cover, certainly way more than I learnt at university. That manual gave me my career.

 

[Wombat]

Yes, it’s hard to believe positive facts on religion, isn’t it

Religion brings people together with a common interest. It is the benefit of shared values and community rather than religiosity per se that confers most health benefits. The idea of eternal life in heaven is a strong sales pitch.

 

[Wombat]

I'm always confused why people are confused about it The definition seem straightforward (from wikipedia):

So electrical representation of digital signal is not an analog signal because it is not analogous to anything.

So a sine wave generated in a signal generator rather than from a transducer is not an analog signal because it is not analogous to some other occurrence?

 

[Wombat]

Analogue vs digital signal: https://www.quora.com/How-does-an-a...l-and-a-digital-signal-from-a-discrete-signal

 

[garbulky]

I swapped a kid at school my Coleco Vision TV game for his Sinclair ZX-81, as I'd been wanting a 'real' Z-80 based computer instead of just development boards. I got the 'massive' 16K extension pack in the swap too.

View attachment 17680

View attachment 17681

Somewhere, deep in a shoebox, is an I/O header and interface PCB, I built for the Sinclair and we used it to initially drive a Tasman Turtle my best friend and I built for a Science Competition (we came second). We wanted an untethered self contained plotter/explorer and my Sinclair was pretty much the only single board computer with enough grunt (or so we thought).

View attachment 17682

I built the Robot, he did the programming. Battery life was too short running the turtle and the computer. The Sinclair crashed everytime the robot's stepper motors pulled current. More NiCads meant the turtle tore up the paper and wouldn't move accurately.

So at the last minute we used one of the school's Apple II clones, ran it from the computer power and he re-wrote the software the night before. It all worked on its rainbow umbilical lead, drawing on butchers paper on the biology lab floor.

He went on to make an absolute fortune in the earliest days of the internet.

Nice story! What kind of thing did he do for his fortune?

 

[svart-hvitt]

Religion brings people together with a common interest. It is the benefit of shared values and community rather than religiosity per se that confers most health benefits. The idea of eternal life in heaven is a strong sales pitch.

Exactly!

https://en.m.wikipedia.org/wiki/Bowling_Alone

(Though I haven’t seen from the research if they’ve tried to isolate for believing in «god» per se).

 

[Blumlein 88]

So a sine wave generated in a signal generator rather than from a transducer is not an analog signal because it is not analogous to some other occurrence? View attachment 17683

Sure why not see it that way. If the sine wave is being used to simulate a tone over a loudspeaker then it is analogous to what you want the speaker to produce. Changing the wave is expected to change the result at the speaker in a one to one correspondence. It is an analog of something.

If on the other hand the sine wave is part of a series which represent something not in one to one correspondence, but which interact to transfer information in some other manner, like tones in a phone modem, then that use of tones or sines is not meant to be an analog of the signal you wish to transmit.

So it isn't analogous because it did or didn't come from a sine wave generator instead of a microphone. It is because it is being used to be an analog of something or it isn't.