Faultfinding DIY Pedal Builds

[Simon Barden]

What you need to take into account is what you actually hear through a guitar amp compared to those oscilloscope waveforms will be something different again; the speaker acts as a low pass filter, so you won't get many of the upper harmonics produced by the distortion unit, resulting in a much 'softer' sound. A direct signal from the fuzz (or distortion or overdrive) unit straight into your audio interface will sound a lot harsher and not very pleasant. Even that will be filtered by the A/D sampling rate setting. Even at a sampling rate of 192kHz, the audio bandwidth is a bit over 80khz (depending on the filter used), which is a lot less than the 20MHz of the 'scope. And unless your monitors have ribbon tweeters, your playback system (be it a studio monitor or hi-fi speaker) will have around a 20kHz frequency response (maybe double that with ribbon tweeters).

Doc, any way you could show some of that effect? Maybe record the output into your system, then get screenshots of the raw, straight playback and playback through a cab sim waveforms?

[DrNomis_44]

What you need to take into account is what you actually hear through a guitar amp compared to those oscilloscope waveforms will be something different again; the speaker acts as a low pass filter, so you won't get many of the upper harmonics produced by the distortion unit, resulting in a much 'softer' sound. A direct signal from the fuzz (or distortion or overdrive) unit straight into your audio interface will sound a lot harsher and not very pleasant. Even that will be filtered by the A/D sampling rate setting. Even at a sampling rate of 192kHz, the audio bandwidth is a bit over 80khz (depending on the filter used), which is a lot less than the 20MHz of the 'scope. And unless your monitors have ribbon tweeters, your playback system (be it a studio monitor or hi-fi speaker) will have around a 20kHz frequency response (maybe double that with ribbon tweeters).

Doc, any way you could show some of that effect? Maybe record the output into your system, then get screenshots of the raw, straight playback and playback through a cab sim waveforms?

That's true and you do raise a good point, I guess what I could do is record the sound of each one of the pedals going into my Marshall amp that's miced up with my Scarlett CM25 condenser mic(it's the only good mic I have), I'll need to sort out my account with Soundcloud first though cause I only have enough play-time on it to upload a 4 minute audio clip, but it is entirely do-able.