OK....now I will reveal how ignorant I am!

[alparent]

I just downloaded VISUAL ANALYSER. Wow! impressive

Not what do I do with this amazing piece of software?

Is there any thing out there like "Using VISUAL ANALYSER for dummies!" 

No I've never used any of the nice things VISUAL ANALYSER dose.

How can this wonderfull tools help me build effects?

Is there any basic things I should know?

I know this is a big question................but I just thought I would ask. 

[R.G.]

I went and looked at it. Neat package!

That's a great little instrument setup for doing effects. The limitations as far as I can tell are only two:
1) the bandwidth is limited to under 100kHz best case with a high end audio sound card (192kHz sampling rate) so you can't see RF oscillations or interference. Not a huge thing, frankly, but a limitation.
2) the input is a sound card input. This desperately needs isolated and protected in case you accidentally probe something with a damaging voltage on it. Sound card inputs have a limited range, and are also connected to the computer's ground, which is connected to AC safety ground on desktop models. So no working on tube amps is possible with this. And without some safety precautions on the input, no probing speaker outputs. These things can fry your sound card, or if you're using sound-on-motherboard, can fry your motherboard. Or both. Scary scenario, but incredibly unlikely if you only mess with 9V powered effects.

I'll probably snag that for some of my quick and dirty tests, even through I have both hardware oscilloscopes and a Picoscope.

The additional info it provides is great.

As to how to use it. 90% of its goodness to effects hackers is simply the ability to act as an oscilloscope and see waveforms. This is infinitely better than the audio probe thing which just tells you there's audio there and roughly how much, and we know how useful that is. Well, maybe 90% is the ability to make a test waveform output and then see the results. 5% is in spectrum analysis and the other meter functions. The last 5% is of use only to more advanced people.

So you only really need to learn to use it as an oscilloscope to get a huge benefit.

[alparent]

  OK

Back to Google to learn how to use an oscilloscope.

Thanks

[R.G.]

Oscilloscopes are simple.

1 - the o'scope provides a visible spot which sweeps across the display area at a smooth, linear rate, providing a fixed time per unit movement of the spot.
2 - independent of the left-to-right sweep, the spot deflects up or down linearly with the voltage on the probe; so the spot wiggles up or down an amount proportional to the voltage.

Generally the sweep across the screen runs so fast that the combination of phosphor glow and human-eye persistence makes you see the sweep as a wiggly line, not as a moving spot. This trace is a picture of how the voltage on the end of the probe varies with time.

Generally, there is a grid on the screen so you can measure how far the spot deflected as it traveled.  You can measure voltage excursions and the time between them just by looking.

There is a vertical position control. This sets the place the trace sweeps across the screen if the voltage on the probe is 0V. Setting this in the middle of the screen on a grid line lets you see both positive and negative voltages. If all your voltages are positive (like in a 9V only pedal), you can lower the position of the trace so "0V" is near the bottom of the screen. Absolute position of the 0V trace does not matter to the o'scope. it just shows you deflection up or down.

There is a horizontal control which sets the left-right position of the trace as it sweeps. This is usually used to get the full trace on the screen and for some esoteric uses you don't need to know about right now. As a beginner, you want your trace to be nice and centered.

If the horizontal and vertical controls are wildly off, the trace may be working find, but set "off the screen" and not visible. This is a problem in real scopes, where finding the trace to start with may be a problem. As a beginner, set them in the center.

The trace may be automatic or triggered. In auto, another trace starts as soon as one trace is over. In triggered, a trace starts only when the signal voltage is higher (or lower) than some threshold, and also moving in a selected direction. Automatic sweep is confusing and essentially useless because the trace sweeps the signal across at its frequency, not the signal's frequency. These generally don't match, so the picture is unintelligible except for the max and min voltages it hits. Triggered sweep synchronizes the sweep to always start at a certain signal voltage and direction. So if you set the trigger for 1.00V positive going, the trace will start when the signal hits 1.00V going up, and will run across. It will not trace again until the signal triggers it again. So a triggered sweep with a repeating signal looks dead still, as the signal retraces its path exactly every time, over and over. Stable triggering is an unbelievably important part of using an o/scope.

What you do is set up auto sweep, adjust the horizontal and vertical positions to show a stable line across the screen and then get a signal on the probe to see if it's small enough to fit on the screen and not too fast or too slow to let you see what you want of it. Then you switch to triggred and adjust the trigger for a stable trace.

The main o'scope deflection is a fixed voltage, perhaps +/-1V. Signals are not so well behaved. They may be +/-1000V or +/-10mV. To be able to see them well, we need to scale the signal to fit on the screen. The probe will have a sensitivity switch to switch between sensitivities. Since there is a grid on the screen, (usually 1cmx1cm on real scopes, just a grid on computer screens), the sensitivity is set in volts per division. So by manipulating the sensitivity setting, you can divide big signals down so they fit on the screen, or amplify them up. The use of Xvolts per division lets you read off the signal voltage direction on the grid.

Likewise, signals are not all the same speed. Line voltage is 60Hz, or 16.666mS per cycle. To see six cycles of 60Hz on the o'scope screen, the sweep has to last at least 0.1Sec. This is probably ten grid divisions of sweep, so the speed of the sweep must be 10mS per division. If you're looking at 500Hz audio sine waves, each cycle is 2mS, so to see six cycles on the screen, the sweep has to be longer than 12mS, so the sweep needs to be shorter than 1mS per division.

Accordingly, the sweep speed is settable in steps. These are almost always 1Sec/div, 0.5S/d, 0.2S/d, 100ms/d, 50ms/d, 20ms/d, 10ms/d, 5ms/d, 2ms/d, 1ms/d, 500us/d... This lets you set the sweep speed for division so you can read time differences right off the trace.

Probes come in two flavors: 1:1 and 10:1. 1:1 probes are just a wire from the input. 10:1 probes are a 10:1 divider and the signal which appears at the scope is 1/10th as big. This is done so you can adjust the high frequency response to be flat, not decreasing from probe capacitance.

And that's the kindergarden 101 version of scope controls. Ask questions.

[GibsonGM]

I've been using Visual Analyser for a few years now (budget Oscope, I live in Maine, lol).  It's a great 'general indicator', and the price is unbeatable (free)!   I always use a cap with my home-made probe (1 to 10uF) to isolate DC - soundcards don't allow DC input anyway, so I've heard.    Adding a buffer to the input of the soundcard might help things out, too. 
Don't expect precision, but it IS pretty accurate for our purposes.  You can calibrate the thing to a known voltage.  The spectrum analyzer works fairly well, too, although frequency limited as R.G. said.

I'm sure there are a few competing and additive side effects such as probe capacitance that skew the results, but seeing a 'pretty close' version of a waveform is better than no waveform at all!  Heed the warnings, keep it to like 5V or less input, use the protective cap, and no high-power circuits. 

Another great use for this is to generate a few different sine waves (200Hz, 440Hz, 1KHz) and export them to an audio program...burn a CD of them, each at like 10 mins.  Then you have a solid input signal to connect to FX so you don't have to strum the ol' guitar every time you're debuggin'...I did that, plus 5 mins of guitar strumming, 5 mins of soloing.   Set the output of the CD player to about 1V P-P to simulate a guitar's output...

[alparent]

OK thanks guys!

I will have to site down at home and reed yours posts again...and again.....and again!

GibsonGM:
Any pictures or instructions on how you built your probes and where to connect them?

[trendyironicname]

Another great use for this is to generate a few different sine waves (200Hz, 440Hz, 1KHz) and export them to an audio program...burn a CD of them, each at like 10 mins.  Then you have a solid input signal to connect to FX so you don't have to strum the ol' guitar every time you're debuggin'...I did that, plus 5 mins of guitar strumming, 5 mins of soloing.   Set the output of the CD player to about 1V P-P to simulate a guitar's output...

This was about the only decent thing I got out of my intro to ece class back in the day.  We would generate waveforms in cooledit, loop it out through our circuit, and back through to our mic input.  I love playing guitar but I despise hitting the headstock on my workbench. 

I just downloaded this, it looks neat.

What problems would I run in to, building something on the hardware side that would scale down the voltages i'm reading.

I'm gonna google the different buffering circuits now but basically, i'm just asking if anyone uses something they're happy with.

[oldrocker]

Thanks R.G. The ocsilloscope write up was great.