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A genuine question.....

For fans of synths, pianos or keyboard instruments of any sort.

Re: A genuine question.....

Postby Martin Walker » Wed Jun 03, 2020 12:50 am

Dynamic Mike wrote:
Martin Walker wrote:1. Not all synths creative 'perfect' sawtooth, triangle, square waveforms, and sometimes it's those imperfections that generate a certain 'mystique'.

I'm not sure I'm buying the first one, because surely that would be simple to emulate

Yes, it is, but my point was that I assumed that a sawtooth was a sawtooth etc., and it was only when I started seeing oscilloscope traces of those from different hardware synths that I finally realised that this assumed design goal of mine simply wasn't always true in practice.

A couple of practical examples:

1. (IIRC) the 'square' wave on a Minimoog often has a mark/space ratio of perhaps 49/51 rather than the classic 50/50 you would expect, so there isn't necessarily a total absence of even harmonics, while phase anomalies often skew the top of the expected square wave shape.

2. Various sawtooth waves have initial 'transient blips' beyond the assumed vertical attack, while the tooth itself may be curved rather than linear.

Here's some typical real world hardware shapes from an SOS feature by Nick Magnus: ... ips-part-4


And another related feature you may find illuminating: ... unterparts

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Re: A genuine question.....

Postby Folderol » Wed Jun 03, 2020 8:08 am

Dynamic Mike wrote:I'm not sure I'm buying the first one, because surely that would be simple to emulate

They are only (comparatively) easy to emulate if you know exactly what is in the original including the sources of components, and routing of wiring looms.

There is a classic case with a guitar wah pedal (can't remember which one now), where slavish copying of the original couldn't produce the same sound. It turned out that the original maker cheaped out on the source of the inductor, and the ferrite core material just happened to have a peculiar contamination that made it behave in a non-linear manner.
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Re: A genuine question.....

Postby The Elf » Wed Jun 03, 2020 10:52 am

I have a few synths here that all use the 3340 oscillator chip. They all sound completely different I promise you!

If I tell you that three of them are the Oberheim Xpander, Sequential Pro-One and the Behringer Neutron then you'll understand that they are very different beasts in all but that detail.
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