true bypassing my crybaby

mayfly

Senior member
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8,173
I haven't had time to look in detail, but it appears that your biggest problem is your input and output jacks are soldered directly to the PCB.

You have a couple of options:

1 - pull the jacks off the PCB, use chassis mount jacks instead, and relocate the PCB.  This would allow you to proceed with the mod as usual

2 - identify the pins on the jacks that you need to interrupt with the 3PDP switch (i.e.the input and output), pull the jacks off of the board, cut those pins off so they don't go through the PCB holes.  Solder wires to the remains of the pins on the jacks, and the underside of the PCB where they would normally make contact.  put the jacks back on the board, then proceed with the mod as usual.  BTW, this would only work for a single layer board - all bets are off for a two layer board.

3 - same as #2, except cut the traces on the PCB instead of cutting the pins.  Again, things get tricky with a multi-layer board.

Got any pics of the board layout?
 

Volitions Advocate

Senior member
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1,239
The mod that responded gave me this link:

http://www.stinkfoot.se/andreas/diy/mods/dunlop.htm

Gives me everything I need.  I"ll be sure to pass this one on.
 

mayfly

Senior member
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8,173
Groovy.  Those instructions look complete.  I see they used the "cut the trace" method.
 

Volitions Advocate

Senior member
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1,239
I only have to "cut the trace" if i opt to not remove the buffer.  Which i probably will do. so i dont have to mangle anything on the pcb
 

gnome

Senior member
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127
Wana's_makin'_a_guitar said:
Whats true bypass? :icon_scratch:

when you turn the pedal off there is no change to tone, non true bypass pedals effect the tone even when not in use
 

Wana_make_a_guitar

Senior member
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2,793
gnome said:
Wana's_makin'_a_guitar said:
Whats true bypass? :icon_scratch:

when you turn the pedal off there is no change to tone, non true bypass pedals effect the tone even when not in use
Ah, ok, so it like completely turns the pedal off and you can only hear the amp or other effects.
 

Volitions Advocate

Senior member
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1,239
In most pedals (ALL) that you buy from manufacturers they have a buffer section or something that reroutes the signal through a different part of the circuit board, or one that digitally turns the effect off, but you still get tone suck or crosstalk (which is still being able to faintly hear the effect when you have it turned off).

So what I'm trying to do is put a physical switch inside there that when I hit it there is a hardwired path straight from my guitar to the amp. so when i turn the wah off. the signal doesn't actually go through the wah at all. just in one jack and out the other.
 

Volitions Advocate

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1,239
WOOHOO FIRST TRY! :blob7: :blob7:
n517473612_1083482_7404.jpg


After work today I'm gonna drill the hole for the led and I have to get one of those brackets for it to mount into, then clean up some of the wires and add a bit of material to the pad that pushes the switch, because the switch i put in there is as high as I can set it and its not quite tall enough.
 

Patrick from Davis

Senior member
Messages
2,197
Just a bit more on true bypass...  It is a switch that has the guitar signal go directly from input to output when the pedal is in bypass mode.  So it is just an coupling between cords when the pedal is off.  Most pedals that you can by now are FET Flip Flop switches that utilize at least 4 transistors that the signal must go through for the switch to work.  The problem is that the transistors can color the signal, and if you put more than three in a row the number of transistors adds up and the coloring of the sound is more noticeable.    There is a buffer and impedance load that these switches have which is often useful.  The two main purposes why these switches are used is that they are noiseless and they are very cheap.  A true bypass switch 3pdt runs $4-6, and transistors are pennies.

The true bypass on Wahs is a major upgrade because the switch/wiring in the Wah can cut signal and cause other inherent hinkie-ness in the bypass position.  The true bypass set up avoids all of this.
Patrick

 

Wana_make_a_guitar

Senior member
Messages
2,793
Patrick from Davis said:
Just a bit more on true bypass...  It is a switch that has the guitar signal go directly from input to output when the pedal is in bypass mode.  So it is just an coupling between cords when the pedal is off.  Most pedals that you can by now are FET Flip Flop switches that utilize at least 4 transistors that the signal must go through for the switch to work.  The problem is that the transistors can color the signal, and if you put more than three in a row the number of transistors adds up and the coloring of the sound is more noticeable.    There is a buffer and impedance load that these switches have which is often useful.  The two main purposes why these switches are used is that they are noiseless and they are very cheap.  A true bypass switch 3pdt runs $4-6, and transistors are pennies.

The true bypass on Wahs is a major upgrade because the switch/wiring in the Wah can cut signal and cause other inherent hinkie-ness in the bypass position.  The true bypass set up avoids all of this.
Patrick
Now that you guys say all that, it is more noticeable when I play through my crybaby on bypass mode, it just sounds muddier.
 

Patrick from Davis

Senior member
Messages
2,197
I think that Volitions Advocate did a post about this, you might try looking it up or contacting him for details...  Sorry, I couldn't help it.
Patrick

 
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