#1
So I'm most likely getting a Whammy IV for christmas and I'm predicting I'll use the hell out of it (i.e. it probably won't come out of my signal chain often). I've heard that it's a real tone sucker though. If I bought a 3PDT switch and modded it for true bypass would it have any negative effects on the pedal?
Quote by forsaknazrael
You should probably mug John Frusciante or Ritchie Blackmore. They're small guys, we could take 'em.

Just look out for that other guy in the Red Hot Chili Peppers, Will Farrel. He's a tall mofo, got a long reach.



Quote by Invader Jim
I give up.

#2
Well, being digital it's probably hard to do that, however I've seen tutorials regarding the subject, and a special site selling either mod kits, or modded Whammy's with true by pass.
Purple string dampener scrunchy.
#4
I don't understand why so many people make a big deal out of true bypass - Is it not as simple as wiring the output across a switch, with one end going straight to the output and one going through the pedal, like this?
#5
Quote by halvies
apparently the whammy is the tonesucker5000, and i suppose if you do the TB mod correctly, it would only affect the pedal the way you wanted it to (ie. true bypass), im not sure that it would be any less tonesucking



True bypass means that there's no output buffer and your guitar signal goes straight through the pedal unaffected when the pedal is turned off.
Quote by forsaknazrael
You should probably mug John Frusciante or Ritchie Blackmore. They're small guys, we could take 'em.

Just look out for that other guy in the Red Hot Chili Peppers, Will Farrel. He's a tall mofo, got a long reach.



Quote by Invader Jim
I give up.

#6
Quote by jimRH7
I don't understand why so many people make a big deal out of true bypass - Is it not as simple as wiring the output across a switch, with one end going straight to the output and one going through the pedal, like this?


no, no it isnt......
#7
Quote by patmann3
no, no it isnt......


why not? I know that sounds arrogant but I'm genuinely intriuged...
#9
^Thats the whole point of true bypass, to stop tonesucking. Otherwise it would be useless.
It wont make any difference when the pedals engaged though, and thats when it really sucks tone.
#10
The easier solution: Make a True-bypass loop pedal.

I'd say buy one, but people charge the hell out of them.

BTW, jim, that's hardwire bypass. The same scheme in crybabys. Except your pic is wrong because with the switch engaged, where does the signal go after it gets through the pedal? Nowhere. The switch needs to be on the output.
Last edited by Invader Jim at Dec 21, 2008,
#11
...

?

or,

?

or, I was thinking,

and save batteries?


What's the alternative to hardwire bypass?
#12
Quote by Invader Jim
The easier solution: Make a True-bypass loop pedal.


I could make one of those but it would be another thing to take up space on my pedalboard. I guess if it came down to it I could do it. Where can I find a diagram/instructions for building one of those?
Quote by forsaknazrael
You should probably mug John Frusciante or Ritchie Blackmore. They're small guys, we could take 'em.

Just look out for that other guy in the Red Hot Chili Peppers, Will Farrel. He's a tall mofo, got a long reach.



Quote by Invader Jim
I give up.

#13
It's just a DPDT stomp switch and 4 jacks (2 for guitar in/out, 2 for FX chain [or pedal] in/out). Pretty straightforward...

edit: jim: the first pic is wrong. The second pic is right. The third is also right (for saving batteries).
Last edited by Invader Jim at Dec 21, 2008,
#14
The Whammy sucks tone like a Lewinsky even when "bypassed", and has a really bright buffer circuit that colors your tone. It also compresses the hell out of your signal so you really need to bypass it when you aren't using it.

Each of those diagrams is wrong, and building a bypass box is not as simple as you might think.

For a True Bypass to be effective, your guitar signal needs to be COMPLETELY disconnected from the pedal circuit, otherwise the pedal will suck some of the tone away - current gets drawn into the pedal and your high end is usually the first to go.

Here is the right way to do it:
http://www.premierguitar.com/Magazine/Issue/2007/Nov/The_DIY_True_Bypass_Lesson.aspx

BTW, Molten Voltage does a true bypass mod on the Whammy as well as a bunch of other really cool mods:
http://www.moltenvoltage.com/whammy_mods.html
#15
...,

?

and the third throw of the switch just turns the LED on/off, so I could equally hook that bit up to the battery instead?

I'm a fool for crappy paint diagrams!
#18
Invader Jim, you are incorrect.

He asked specifically about True Bypass and the last diagram he drew was exactly right. You wrongly assumed that he wanted to discuss "hardwire bypass" because of his faulty original diagram.

I would be interested to hear what you think is wrong with it, as it tracks the diagram in the link I posted exactly.

To answer your other question JimRH7, your idea about disconnecting the batteries is irrelevant because the Whammy 4 runs off an AC adapter.
Last edited by Tonyrocks at Dec 22, 2008,
#19
For one thing, jimRH7 isn't the TS. He was trying to find a hardwire bypass scheme first, because I said that's what his first diagram closely represented. He then made us a few more diagrams and wanted to know which was right, which I told him. The part about disconnecting batteries is so the thing doesn't have to be unplugged from the guitar after using it.

In TB, the input is not connected to the pedal circuit unless the switch is thrown. In jim's last diagram, The switch is wired funny. I mis-read it last time and that's my bad, but the switch is still wired funny.

When I say true-bypass, this is what I mean:

#20
Invader Jim, in JimRH7's earlier diagram which you said was right, the second one in a series of 3, the guitar input stayed connected to the pedal circuit which is always wrong. That will always suck tone because some of the input current gets drawn into the pedal circuit, and that is what true bypass is designed to avoid.

What seems "funny" to you in the last diagram is that the pedal input is grounded when the circuit is bypassed. There is a very good reason for that -- in high gain pedals like distortion, a floating input can create a hell of a lot of noise which will be heard through the common ground, unless you ground both sides of the pedal circuit input.

The diagram you drew leaves the pedal input floating. It also ignores the fact that the guitar and pedal circuits share a common ground. These two facts combined are a recipe for noise when bypassing high gain pedals.

What you drew is a common mistake, which will work with the Whammy 4, but will result in plenty of noise with distortion pedals.
Last edited by Tonyrocks at Dec 23, 2008,
#22
but, true bypass and hardwire bypass both involve just the one actual component (a switch) you have to buy right? I mean, there's no active electronics etc. involved? (I suppose your all thinking" YES JimRH7, Isn't it implyed in the name?" - I'm just double checking.)
#23
Sunburst, you are right that what Invader drew is "standard", but it is also wrong, and lots of companies are making crappy "true bypass" mods and boxes.

That design works fine with most pedals, but distortion pedals and some delay pedals will make lots of noise if the pedal input is not grounded when bypassed. Read the article that I linked if you need more info.

JimRH7, you are right that there are no active electronics in a true bypass setup unless you want an LED indicator on your switch. However, some bypass boxes are also buffers which are active circuits. These are not properly called "true bypass", but are very useful in some long pedal chains.
#24
Quote by Tonyrocks
Invader Jim, in JimRH7's earlier diagram which you said was right, the second one in a series of 3, the guitar input stayed connected to the pedal circuit which is always wrong. That will always suck tone because some of the input current gets drawn into the pedal circuit, and that is what true bypass is designed to avoid.

I'm aware of that. Like I said, I was talking about hardwire bypass, regardless of whether jim was or not. I already admitted that that was my fault for mis-understanding.

Quote by Tonyrocks
What seems "funny" to you in the last diagram is that the pedal input is grounded when the circuit is bypassed. There is a very good reason for that -- in high gain pedals like distortion, a floating input can create a hell of a lot of noise which will be heard through the common ground, unless you ground both sides of the pedal circuit input.

I know this. It seems "funny" to me that the switch is also connected to ground, thus grounding the signal when the switch is thrown, i.e. killing it. Or am I not seeing something?

Quote by Tonyrocks
The diagram you drew leaves the pedal input floating. It also ignores the fact that the guitar and pedal circuits share a common ground. These two facts combined are a recipe for noise when bypassing high gain pedals.

I left out the grounds and stuff because (I had assumed) it went without saying. Apparently not, however. If you want me to correct it to show you I at least know a little bit about what I'm talking about, I will gladly do so.

Quote by Tonyrocks
What you drew is a common mistake, which will work with the Whammy 4, but will result in plenty of noise with distortion pedals.

You mean the 'floating input' thing? See above.
Last edited by Invader Jim at Dec 23, 2008,
#25
Quote by jimRH7
...,

?

and the third throw of the switch just turns the LED on/off, so I could equally hook that bit up to the battery instead?

I'm a fool for crappy paint diagrams!


IJ - I don't know what it is you are seeing in the diagram. When the switch is up, as shown in the diagram, the guitar input signal goes through the pedal circuit then to the output jack. The input and output jacks are also disconnected from each other when the switch is up. Normally a schematic will show that both halves of the DPDT switch are always toggled at the same time which JimR's schematic doesn't show. That might be confusing you because it is not a proper schematic. I think the dashed line is his attempt to show that and does NOT show a signal path.

When the switch is down, the guitar signal goes directly from the input jack to the output jack AND the pedal input gets grounded. The guitar signal is not killed when the signal to the pedal circuit is grounded.

Whether you know what you are talking about or not doesn't matter to me. Leaving the grounds out makes a big difference when talking about true bypass.

To answer your last question, yes, the floating input doesn't matter on the Whammy 4 and it doesn't matter on most pedals, but it makes a huge difference on lots of distortion pedals, including my Boss Metal Zone. I figured that out the hard way...
#26
I know what the dotted line means. It's to show that both poles of the switch are thrown at the same time, i.e. a dual-pole switch.

Thanks for pointing out the grounding thing, but in TB the pedal isn't grounded. It's totally bypassed, like in my diagram (but with grounds of course). With the pedal bypassed like that, you don't NEED to ground it or w/e, since the guitar douesn't even SEE it (except the ground). The point of TB is to completely isolate the pedal from the guitar (again, save for the ground).

Random schem from the internet: http://www.scribd.com/doc/2474360/Dunlop-Crybaby-Vintage-Guitar-Effects-Schematic

Yeah it's a crybaby and yeah it has errors, but see the switcing on the input and output? True bypass. That's what I've been trying to say this entire time.
Last edited by Invader Jim at Dec 24, 2008,
#27
Quote by Invader Jim
I know what the dotted line means. It's to show that both poles of the switch are thrown at the same time, i.e. a dual-pole switch.

Thanks for pointing out the grounding thing, but in TB the pedal isn't grounded. It's totally bypassed, like in my diagram (but with grounds of course). With the pedal bypassed like that, you don't NEED to ground it or w/e, since the guitar douesn't even SEE it (except the ground). The point of TB is to completely isolate the pedal from the guitar (again, save for the ground).

Random schem from the internet: http://www.scribd.com/doc/2474360/Dunlop-Crybaby-Vintage-Guitar-Effects-Schematic

Yeah it's a crybaby and yeah it has errors, but see the switcing on the input and output? True bypass. That's what I've been trying to say this entire time.


IJ, let me try one more time to explain.

The guitar signal is never** "completely isolated" and the pedal is never** "totally bypassed". This is because the pedal and the guitar share a common ground. Noise can show up even if it only appears on the ground. This is really quite fundamental and something you will probably need to learn the hard way.

It is not about what the guitar "sees" (i.e. impedance), and it is not about current getting drawn off the guitar and sucking the tone, as that is not happening in the circuit you drew. The issue is the noise from the pedal getting into the signal path through the common ground. This noise occurs in HIGH GAIN PEDALS because the input is floating.

The crybaby schematic you linked is irrelevant. Like I have said at least 3 times now, FLOATING INPUTS ARE ONLY A PROBLEM WITH HIGH GAIN PEDALS.

** you can build a proper true bypass without grounding the pedal input, BUT you will need to isolate both the tip and the sleeve on the input and output jacks with nylon bushings and use a 3PDT switch that disconnects the pedal ground from the guitar signal path. But why go to all that extra work.
#28
It was my understanding that dotted lines in an electronic schematic mean "mechanical connection", so you can show them on, like, motors and dynamos and stuff aswell. Is this right?

Is there a proper symbol for switches with more than one throw?

**disclaimer - the rest of this post is waffle**
I think I still don't properly understand ground. I mean, I was thinking about it, and if the amp/pedal etc. is fixed to a wall socket, and the wall socket is wired to onther sources of ground, then ground is like an infinitly large capacitance, right? Isn't that how it works?

I know the point you are making about the signal being able to "suck tone" from the signal from the output aswell as the input tonyrocks, but I disagree with the other point - that ground can transmit buzz etc - on this basis. If it's an infinite capacitance, then the signal that escapes to it has no driving force to "push" it through amplifiers etc.

the point is that ground is allways = 0v.
Last edited by jimRH7 at Dec 24, 2008,
#30
JimR, ground is very rarely 0v when you are talking about an A/C signal path. The first thing you both need to do if you want to understand audio signals is to buy an oscilloscope.

The second thing is to learn the basics about transistors and operational amplifiers (op amps). They are the building blocks of audio effects. Until you experiment with op amps while keeping the input floating, you will never really understand what I have been trying to explain in the most basic possible terms.

I am not trying to offend you, I am just trying to say that audio electronics are way way more complicated than they seem like they should be.

Suffice it to say that even in DC circuits, ground is never exactly zero and noise gets back into your audio signal through the ground all the time (e.g. 60hz hum). With high gain pedals, a floating input results in a huge noisy square wave on the output of the op amps or transistors that drive almost all distortion pedals. This is because the gain on the op amp is set as high as possible to generate a square wave output from an audio input. When there is no audio input, a floating input looks like a pretty loud signal because it is halfway between ground and +9v or whatever and gets amplified and clipped at the same time and creates a huge noise which is loud enough to overcome the resistance in the ground and make its way to the output jack.

Anyway, it takes a lot of effort to understand this stuff Invader Jim. If you give up now, you will never understand.

Electronics seem intuitive on the surface but are extremely unpredictable and tempermental just below the surface.

Good luck guys. I am out of here.
Last edited by Tonyrocks at Dec 25, 2008,
#31
but Invader Jim = Win..
he knows his ****...IF you read his wole post..you will understand he IS correct!!!
=BROLY - HIS POWER IS MAXIMUM=
#32
:stickpoke

I still don't belive you tonyrocks. ground should be 0v, by definiation in my oppinion. If it isn't, they shouldn't show it as ground in the diagram.
#33
Ok guys, I've got a question for you. I know it's been a month since the last post, but, here it goes...

I know what true bypass is and how it looks. Now, the problem is, all those companies claiming this and that, and being full of crap. For example, MXR claims "hardwire bypass" in some of their pedals (like the EVH Phaser) (which we all know sucks tone still and is NOT true-bypass) and they also claim "true-hardwire bypass" such as in the Carbon Copy. Now, what's the deal!!?? If we know, true-bypass and hardwire bypass are not the same thing, then why the hell call something "true-hardwire bypass" to make things even more confusing.

To be honest, I'm making some changes on my board and I'm linking together all my true-bypass pedals (those I'm perfectly sure are really true-bypass) Example: Keeley Modded Rat 2, Keeley Compressor, Vox Clyde V848 Wah. Then I'm probably going to use a TB loop to put all the others in. Some of I know are not TB, and others which I'm simply not sure of. Those I'm not sure of... MXR Carbon Copy, MXR EVH Phase 90.