Iron Butterfly Fuzz Wah (Fuzz section)

[bre]

Hello,

I've just found a very interesting fuzz-wah pedal here: http://www.freestompboxes.org/viewtopic.php?f=19&t=24693.

In the topic is posted a complete layout (for both fuzz and wah sections), but I want to build only the fuzz section. Anyone could help me?

Thank you very much!

[anders]

It looks like something like this:

[bre]

Wow...you're a fabulous man Anders...thank you very much!
I hope to have time to build it this night :)

[anders]

Great let us know how it goes. I found a couple of mistakes in the layout. Sorry about that. I have updated it and it should be ready to go now.

[bre]

Thank you very much, Anders!

I've just finished to build it and it worked from the first try...you're great!!!

I used 2 pieces of BC547B having the gains between 250 and 300. I think there is a problem with the value of the Tone pot...1M seems to be huge...the output is low and, in the middle, there is almost no sound (is very week)...practically, you can obtain only 2 usable settings: very bassy (with the pot at minimum) or very trebly (with the pot at maximum)...I replaced it with 500K and it sounds better...but I think I will replace it with 250K as soon as possible...anyway, it's an interresting fuzz!

[Beaker]

From the thread on FSB that sounds absolutely right - bassy CCW, volume drop at 12 o'clock, and screeching treble full CW.

You have to remember that some of these early fuzzes had "tone" controls that were primitive, and often bizarre. They are nothing like what we would now consider to be an effective and useful tone control.

It might well be ripe for improvement though. I built an Ace Tone FM-2 Fuzzmaster that had a very strange, and pretty poor tone control. With a bit of trial and error, I was able to come up with a minor mod, that worked much better. It's highly likely that this could be inproved in a similar way.

http://tagboardeffects.blogspot.co.uk/2014/10/ace-tone-fm-2-fuzz-master.html

Take a look - it might give you some pointers for modifying.

[bre]

Thank you Beaker for your informations!

I replaced the 1M log tone pot with a 250K lin one and it seems to be more useful now :)

[anders]

Thanks for verifying it and experimenting with the pot values. I think I will give this one a go during the weekend. That tone/volume control looks really odd.