Hello Everyone...
Bit of a strange question here, but I've got to ask it. I've recently finished Tim E's PWM without the LFO, but I've got a bit of a problem... I don't know what it's supposed to sound like !?!? Basically, It's ended up as a really nice fuzz with a 'sweepy' tone control. Is this correct ??
Correct or not, I really like it so I'm not gonna change it, but I've got enough parts to build another if I've bollo***ed this one up :)
Thanks.
You've got it right. I have some clips posted on the Basic Audio site sound page, but there's a mistake in the description.... there wasn't any distortion added outside of what the pedal produces, a very thick fuzz. Also I recommend the LFO add on 'cause it really brings it to life!!
Thanks for the reply...
I'd make the LFO switchable if I added it 'cos I can see a problem, which is, at the most extreme setting of the frequency pot, the sound disappears completely !! I've used the correct parts and values throughout, so again, I don't know if this is a characteristic of my build or the effect itself. If the LFO sweeps through the full frequency range, it'll cut out at the extreme 'high-end' making almost a tremelo effect.
Cheers.
That's what it's supposed to do, almost like a thru-zero flange sound. That's the point at which the width of the pulse (rectangle wave) is getting narrower and narrower so that it effectively disappears.
Not verified, but looks correct.....let me know if you spot any errors
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=36191&g2_serialNumber=1)
Has anyone seen a layout for the added LFO version? I remember having a hard time putting it together, might be good for newbies like I was back then.
An expression pedal is totally awesome with this circuit as well. It sounds like an alien wah pedal. You do have to put a limiting resistor in series with the resistance in the expression pedal because of exactly what you mentioned: at the extremes of the pulse width modulation the sounds disappears. I actually added a pot rather than a fixed resistor to vary the the limiting so I could change the range of the pwm. Tim Escobedo's circuits are crazy fun! :)
Quote from: bluesdevil on September 03, 2008, 05:40:18 PM
Has anyone seen a layout for the added LFO version? I remember having a hard time putting it together, might be good for newbies like I was back then.
That would be very useful indeed if anyone's got it !!