Mad Professor - Snow White Auto Wah  [traced]

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
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roseblood11
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Post by roseblood11 »

I think there is no simple way of doing that for this circuit. But there is a similar mod for the MXR envelope filter. Listen to the Emma Discumbobulator, which is based on the MXR.

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ambusch
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Post by ambusch »

Ressurecting an old thread where the pictures don't work anymore except for one or two. It doesn't look like D6 is a typcal 1n4148. I can barely make a 28 or a 29 on that one... Is D6 really a Zener diode?

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alexradium
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Post by alexradium »

ambusch wrote:Ressurecting an old thread where the pictures don't work anymore except for one or two. It doesn't look like D6 is a typcal 1n4148. I can barely make a 28 or a 29 on that one... Is D6 really a Zener diode?
zener is 5,1V and is just to reduce voltage for the On state led.
rest are 1n4148 and 1n4002

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jsaily
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Post by jsaily »

An old thread for sure, but has anyone managed to extract the changes needed for the Bass-version of this pedal?

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jsaily
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Post by jsaily »

I have modified the filter sweep range from the standard 250-2500 Hz to 100-1300 Hz by changing the capacitors C5 and C6 to 47nF (were 22nF). This is confirmed by audio network analyzer and also with 5-string bass! It now quacks like a duck and feels very responsive & funky with bass.

My idea is to put a DPDT switch in there to switch in additional parallel 22nF caps (C5 & C6 associated with LM13700) for the bass mode. The guitar mode has then only the standard 22nF caps.

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Aaron323
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Post by Aaron323 »

Sorry to resurrect an old thread, I see the last comment about bass mods.. The latest version of mad professor snow white actually has a toggle switch labelled bass and guitar. Do you think it is basically switching in the 2x caps at c5 and c6, or something a bit more substantial?

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