Date:         Sun, 7 Jan 2007 20:29:54 -0600
Reply-To:     Association for Recorded Sound Discussion List
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Sender:       Association for Recorded Sound Discussion List
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From:         phillip holmes <[log in to unmask]>
Subject:      Re: square waves....Re: [ARSCLIST] Libraries disposing of records
Comments: To: Association for Recorded Sound Discussion List <[log in to unmask]>
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Well, if there's a capacitor in the signal path, you'd have nothing.  
The cap would block the DC, and there'd be no signal.  If you don't have 
a capacitor, you might wind up with a fried amp or speaker.  Am I wrong?

Steven C. Barr(x) wrote:
> ----- Original Message ----- 
> From: "phillip holmes" <[log in to unmask]>
>   
>> A square wave on a record doesn't look like a square because of the 
>> velocity involved--or something--that I can't explain.  A square wave is 
>> built up of stacked "odd integer harmonics" and contains multiple 
>> harmonics.  Somewhere around 12 harmonics, it really looks like a square 
>> wave.  The more harmonics present, the more perfectly formed the square 
>> wave becomes.  A perfect square wave would require infinite bandwidth 
>> and infinitely fast electronics (forget the stylus, we can't even 
>> generate a perfect square wave, only a mathematical representation of 
>> one). 
>>
>>     
> Now...let's assume we have a DC battery and a switch...so the output
> of the combination is either "current" (switch closed, DC voltage
> present) or "no current" (switch open, no DC voltage). We physically
> flip the switch between the two, say, five times per second. Since
> the voltage rises from zero to X as soon as the switch makes contact,
> don't we get a five Hertz "square wave?" Assume we have nice straight
> wiring (no inductance)...what, if anything, would distort the wave
> shape of our output?
>
> Steven C. Barr
>
>
>
>