# Diode selection switch to Hoof?



## BurntFingers (Feb 15, 2020)

Ungula, sorry.

I'm interested in adding some diodes to a switch for clipping options. Thing is the board is already made and wired up as the cloven hoof variant, which I like just fine but options are options.

I'm wondering about using an on-off-on dpdt with a pair of different diodes on the too and bottom lugs and wiring the middle lugs to where the existing diodes start and end respectively.

I'm trying to work out if when in the off position id still use the board diodes.

And this is something I can retrofit to any pedal with diode clipping so if it's not applicable to the hoof, please indulge my curio

Like this perhaps but instead of ground, to the output of existing diodes.


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## Nostradoomus (Feb 15, 2020)

It will work but you’ll need to use 2 switches as the hoof/muff has diode clipping on 2 transistor stages. You’ve got the idea though!


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## BurntFingers (Feb 15, 2020)

Nostradoomus said:


> It will work but you’ll need to use 2 switches as the hoof/muff has diode clipping on 2 transistor stages. You’ve got the idea though!



Yeah that was something that dawned on me once I had a sip of coffee. 

It's looking like 1 switch per pair of diodes, so 2 in total: 1 with si and 1 with ge.

When it comes to wiring those in so when it's off the board diodes are selected and when on the switch diodes are selected... That's where I'm stumped.


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## BurntFingers (Feb 15, 2020)

I did the mod to a Lovepedal clone I just made... A clone of a clone basically.

I had a simple on/on toggle lying around. On one end I put a pair of 3mm red LEDs in series. The other lugs were connected to the start of d1 and the end of d2. It changes the sound slightly by removing some bass. The LEDs don't light up so I don't know if I literally just removed a clipping stage.

Either way there's something happening.


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## Barry (Feb 16, 2020)

I like the artwork, nice build!


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## Nostradoomus (Feb 16, 2020)

I think you’ll have better results if you put the diodes in parallel (piggybacked + to -) but yeah you’ve got it!


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## BurntFingers (Feb 18, 2020)

Nostradoomus said:


> I think you’ll have better results if you put the diodes in parallel (piggybacked + to -) but yeah you’ve got it!



Just a thought. Do I have to wire the switch to ground anywhere, or does it ground through the circuit path on the board? There's no inordinate buzzing and there is a difference in sound when the switch is flipped, I'm just wondering what it is I'm actually doing here and if the LEDs are actually being utilised.

Im too far down the switch rabbit hole to see clearly.


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## Nostradoomus (Feb 18, 2020)

Not in the ungula. It’s circuit dependant though, just check the schematic before you start fiddling!

Series diode clipping really only uses the first diode I think (I’m not a wizard...yet), but in parallel their forward voltage is added together and you end up with a louder but less distorted clip. Some circuits will make the LEDs light up (IE:Turbo Rat) and others will not.


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## BurntFingers (Feb 18, 2020)

I haven't done it to the ungula yet, only the eternity clone in the image and wired as on the pic: 2 diodes in series on one lug, then the middle lug goes in to d1, the other end lug goes from the end of d2.

I guess I could run a crocodile clip to ground and see what happens.


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## Chuck D. Bones (Feb 18, 2020)

If i understand correctly, you want to be able to select between three pairs of diodes with one DPDT on-off-on switch.  For that to work right, the diodes on the board, the ones that are always connected, need to be the ones with the highest voltage drop.  That would be the LEDs.  Perhaps you can clarify what 3 diode options you're after.  No diodes is a viable option for this pedal.  To further muddy the waters, you can also think about what Way Huge does with the Swollen Pickle: put a pot in series with diodes.

Let's be clear about series & parallel: the diodes in the switch picture above are in parallel.  

Don't ground either end of the diodes on a BMP, that will kill the signal completely.


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