Fuzzy Muff: A transistor fuzz with 5 sets of selectable clipping diodes

[xixiviii]

First - I apologize for the wordy post...
Second:  I started building effects in October 2013 so I apologize for my lack of understanding when it comes to the finer details of circuit building - my knowledge is growing daily thanks in large part to this forum and it's contributors...

I wanted to post my latest build and ask "does it immediately stand out as being a direct clone of something already existing?"  I am wanting to call it "my version of the EHX Muff Fuzz" but don't want to mislead anyone if I have literally made an exact copy of something that already exists.  If I have it was not my intent - and was simply dumb luck.

It is basically an EHX Muff Fuzz with a gain pot and selectable clipping diodes.  This idea of selectable clipping diodes is not new - I realize that, however I wasn't able to find that this exact version exists.  If it does I would like to give the owner credit and provide a link to their schematic.  As a new guy here, I want to make sure I don't step on any toes or upset anyone.

I started with the EHX Muff Fuzz schematic that Dano drew up years ago at Beavis Audio located here.  I added a gain pot to it, then I replaced the existing diode clipping stage with 5 selectable symmetrical clipping options.

SW1:  Germanium Clipping(1N34's)
SW2:  Silicon Clipping(1N4148's)
SW3:  Rectifier Clipping(1N4001's)
SW4:  Schottky Clipping (BAT41's)
SW5:  LED Clipping (Water Clear White) 

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I used DIYLC to layout the perfboard based on how it originally drew it by hand on paper (my first time to use the program).  Any constructive critism is welcomed since it was my first time to ever layout a perfboard from a schematic.  I wasn't sure if I put the gain pot in the best place, but it worked so I figured it was ok there.

The circuit is complete and seems to work well.  If interested, more information on the build is located here.  I am also working to make a few sound clips to upload.  Some things that I noticed are that the GE and Schottky selections have pretty low volume compared to the Si and Rectifier options (all can be balanced to unity with the volume know though). Also, the LED option sounds much different than the other four – thicker and meaner maybe?

I recently got my first oscilloscope and am starting to gain an understanding about how different diodes clip in different ways, but for now - I just speak in baby terms.

Below are a few pics.

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Thanks in advance for any constructive thoughts that can help me improve as I try to go from a "pure copier of already existing stuff" to an "experimenting contributor" that adds some value to the hobby.

[innovine]

Is the switch for the led necessary? If other diodes are enabled they'll clip/conduct first, and 'override' the leds.. I think

To deal with the volume drop, have you tried adding another diode in series?

Nice pedal finish by the way, looks awesome

[teemuk]

Some things that I noticed are that the GE and Schottky selections have pretty low volume compared to the Si and Rectifier options

Those diodes have a lower forward voltage. They clip at lower input signal amplitude and when you drive them with "fixed" input signal level they clip at lower voltage threshold than the other diodes.

Also, the LED option sounds much different than the other four – thicker and meaner maybe?

And these have a higher forward voltage. Again when you use a fixed input level the LED with higher threshold will clip less than a silicon, which has lower forward voltage, which in turn clips less than germanium that has even lower forward voltage.

Which begs a couple of questions: How much are you really listening to effects of different diode characteristics versus the effect of their very different forward voltages? How different would this be if you used just a single diode clipper but made the input amplitude variable?

[xixiviii]

My advanced apologies to anyone I offend with my ignorance - I looking to learn from each and every comment - so I might have questions about them.

Is the switch for the led necessary? If other diodes are enabled they'll clip/conduct first, and 'override' the leds.. I think

And my education begins...

I haven't been through the build in detail yet with a scope or even a multimeter.  My thinking was that with all switches "off" there would be no clipping whatsoever and the signal would simply pass to the volume knob from the 100nf unclipped.  I didnt think the LED's were even being touched by the signal until I bridged the connection with the switch - this is why I put it there.  Thank you for the input - it goes directly into my "need to learn more about" file

Which begs a couple of questions: How much are you really listening to effects of different diode characteristics versus the effect of their very different forward voltages? How different would this be if you used just a single diode clipper but made the input amplitude variable?

I like where this is going.  It is a simple enough build that I plan to experiment a lot with it.  This comment goes directly into the notebook for things to try.  Thanks!!!