Simple h/w vs s/w oscilloscope comparison for audio use

Published on Oct 3, 2013 Phil Tipping·55 videos

No audio in the video.  Posting for informational purposes for those interested.  A scope is a great thing to have on hand when going over synth basics with friends and family new to synthesis.  There are scopes available for iOS as well.

"If you've not tried a s/w scope before, this simple side-by-side demo shows a variety of audio waveforms in both.

The h/w scope is a Tektronix 475 (a bit blurred due to camcorder focusing); the s/w scope is a free one called Soundcard Scope 1.41 by Christian Zeitnitz running on a Windows XP PC - other products are available. Test waveforms were generated from a Dotcom modular synth using the Q106 VCOs and Q108 VCAs.

This s/w scope takes its input from the PC's sound card, in this case an M-Audio Delta, and uses the left & right channels to provide 2 independent displays.

The main disadvantage with the s/w scope is the restricted frequency response due to the soundcard. The lack of DC coupling limits the usefulness for slow moving ADSR envelopes or measuring DC offsets, but it may be possible if cards are available with DC inputs (cards with DC outputs do apparently exist, as exploited by Expert Sleepers' Silent Way for generating CV levels for synth control).

Apart from that, the s/w scope seemed adequate for non-critical use and also provided lots more 'extras' such as easy frequency measurement and freq/fourier analysis plots. This particular program also has a built-in 2-channel signal generator which can be looped back to itself internally so you can explore waveshapes & Lissajous figures without any external gear."