Oscilloscope as Stereo Phase Monitor? Is that possible?

[Bluzzi]

Just wondering out of the top of my head so it may be a crazy idea.

I've got a friend's oscilloscope here on "indefinite" loan. I'd love to havve a phase monitor but man their expensive! Thats why I get the feeling I'm being naive here. I searched for DIY Phase Monitor etc. and got nothing.

Anyone tried this?

jim

 

[David Kulka]

If it's in decent condition and has 2 inputs it can work as a phase scope, and very well. Just connect left and right to inputs 1 and 2 and put the scope in X-Y mode, you're set.

 

[Bluzzi]

David, Woa.... gotta try that...

Thanks

jim

 

[clintrubber]

It's indeed a very nice indication, gives more info than a single LED-bar: unsurprisingly you get level as well.

So be warned, you might be shocked by the 'blocked' display you get for some CDs (clipped/limited to the max).

For convenience you could tilt your scope by 45 degrees (unless youre using something like a Tek 535 :wink: ) to get a straight vertical line for mono.

Regards,

Peter

 

[gyraf]

And consider pre-shaping the incoming signal with an automatic-level-control...

Jakob E.

 

[Bluzzi]

[quote author="gyraf"]And consider pre-shaping the incoming signal with an automatic-level-control...

Jakob E.[/quote]

Such as a GSSL? :grin:

jim

 

[clintrubber]

FIW, EW+WW-mag had a nice DIY-'scope-emulation'-circuit by means of a LED-matrix years ago. Had a few added features as well.

But a green cloud looks the best.

 

[lanxe]

I have seen these x-y plots of phase but i am unsure of what we are looking for. i understand where the plot comes from, but can somebody give me examples of what to look for good/bad?

Ryan

 

[Freq Band]

Tell us more scope tricks !!

I've begun to gather a decent array of test gear.

For us non-EE or non-studio tech guys, the dream web site (or textbook) would be one that described all the standard tests to tune-up and identify problems with..... audio related gear.....in as simple language as is possible.

.....standard tests for :
Distortion
Inter-modulation distortion
S/N
PSU testing
Spectrum analysis
In-circuit tests
Phase, overshoot
Amplifier biasing
etc,....

How many "I have a problem" threads do you think would be eliminated by referring to such a site/reference such as this?

Just a thought.

Right now I'm doing it the long way......buying the gear, plowing through the manuals, not understanding 1/2 of what I'm reading, trial and error.
But the more I jump into it, the more I learn by 'hands-on'. I'll re-read something a month later, and realize, "...NOW I understand ! "....because the blanks are slowly being filled in....slowly.


=FB=

 

[clintrubber]

[quote author="Freq Band"]Tell us more scope tricks !!

I've begun to gather a decent array of test gear.

For us non-EE or non-studio tech guys, the dream web site (or textbook) would be one that described all the standard tests to tune-up and identify problems with..... audio related gear.....in as simple language as is possible.

.....standard tests for :
Distortion
Inter-modulation distortion
S/N
PSU testing
Spectrum analysis
In-circuit tests
Phase, overshoot
Amplifier biasing
etc,....[/quote]
Some Blackling (anybody still Googling :shock: :wink: ) wil give you lots of info, but the Audio Precision info-book comes to mind as first. It's the book you get with their test-gear but it's now also free as a pdf.
Despite you most likely don't have AP-testgear (I don't either, just have it at work), that book & their info will still be a nice start.

Links here: http://www.groupdiy.com/index.php?topic=8785&postdays=0&postorder=asc&start=14

Regards,

Peter

 

[SonsOfThunder]

Bob Metzler's book that Peter refers to should be required reading for anyone doing DIY audio. I make all our new guys at work at least skim it. If you get all of that down, you can figure out pretty much anything in audio test, IMO.

HTH!

 

[clintrubber]

[quote author="SonsOfThunder"]Bob Metzler's book that Peter refers to should be required reading for anyone doing DIY audio. I make all our new guys at work at least skim it. If you get all of that down, you can figure out pretty much anything in audio test, IMO.

HTH![/quote]
I saw the pic of the book-cover was gone. Repaired.
Let's add it here as well:

There seems to be a more direct link by now as well:
http://ap.com/library/books.htm

Cheers,

Peter

 

[clintrubber]

And last but not least there seems to be an added freebee: a test-disc. Dunno how useful it'll be without AP-gear though.

Introduction to the Fundamentals of Audio Test and Measurement 1 disc set
Order from AP
(Free)

Disc one of of the Fundamentals series. On your free first disc in the series you will find:

- What’s Unusual About Audio Measurement
- Measurement Units
- Introducing AP Software
- View Options
- Menus, Icons and Tools
- Analog Inputs and Level Meter
- Crest Factor
- Analog Output Generators