Another thing, I was convinced that analog scopes are in general better for audio electronics, am I mistaken?
Touchy issue.
Depends, really. With audio circuitry, or any electrical circuit for that matter, everyone knows the *ideal* design is one which contributes zero self noise or distortions to the signal you intend to introduce to the circuit. A circuit with zero self noise is obviously not possible, nevertheless your test equipment has to be capable of at least meeting, or preferably bettering, the *best* specification of your design, or you simply won't be able to "see" what you got. Whatever that equipment is, be it digital or analog, it firstly has to be up to the task of giving you accurate feedback on what is going on with your designs.
If normal run-of-the-mill audio circuits are what you have in mind, almost anything in the way of an oscilloscope will get you going. If you aspire to lash up something that delivers gobs and gobs of really clean, quiet gain, or if your circuit has complex signal summing going on, then you are going to have to examine the noise floor much more carefully because, obviously, the audio will only be as clean as the noisiest point in the signal path.
Personally, I like analog scopes for audio work. But then, that's just my preference...no analog zealotry here...they're just bloody tools after all. Get something that works and start changing the world before life runs out, I say. One of my favorite scopes ever for audio work is an old analog HP 1201A storage model that was very, very good for electromyography verification and other sensitive low speed medical/bio-mechanical stuff. This is only a 500kHz scope. You really don't need much bandwidth for audio, often much less than you think. What makes this scope so wonderful for audio signal work is not stratospherically high bandwidth, but it's extremely quiet differential front end amps, outstanding CMRR, very low 100uV/DIV deflection factor and the 50k bandwidth limiting that helps clear up the range you are most concerned about examining closely. With this old "obsolete" instrument you can have a peek way, way down into a signal. Whether you care to, or are indeed able to, design an audio path that requires that degree of verification is, of course, another matter.
*Sigh*...and on that issue...if nobody can hear it, then who really cares. It's all a bloody great wank fest after that. The average healthy homosapien can only be expected to hear, at most, from 20Hz to 20kHz. That's the range you want to keep clean. In reality, it's even narrower than that because our hearing is much more sensitive in the mid to high-mid ranges...artifacts are much easier to discern in that spectrum. Even if there are spurious signal anomalies out at 20MHz....10MHz....1MHz even. Other than bats, and possibly Superman, nobody is going to care, especially after steep Nyquist filtering kills it all. Unless noise/distortion artifacts fold back into the audible frequency spectrum, it's entirely irrelevant. Even a highly specified digital audio circuit, using an absolutely exceptional 192KHz DAC for conversion purposes, can be lashed up using a low speed scope for verification, providing it has the moxy to allow you to see into your signal to the depth necessary to expose any noise components that *will* mess with audible signal integrity within the spectrum of frequencies folks actually do hear. And that's all that matters.
Because, if you can't hear it...well then, it never really happened in the first place, did it?
Home
Help
Search
Login
Register
