Companies that are dishonest about true bypass.

[uOpt]

Re: Companies that are dishonest about true bypass.

How is that "mosfet relay" then supposed to not change impedance?

 

[Demanic]

Re: Companies that are dishonest about true bypass.

^^
I wonder if they could be engineered so as not to do so.

 

[PFDarkside]

Re: Companies that are dishonest about true bypass.

Class A is for awesome right?

Obviously. Don't tell anyone, but I've got a super secret amp design that runs in Class AAA++ it's going to knock the doors off the guitar amp world.

 

[MrTondo]

Re: Companies that are dishonest about true bypass.

How is that "mosfet relay" then supposed to not change impedance?

That was also my question. In the end it will, the question is just how much? Let's simply assume the transistors act like diodes when they are in bypass mode, that means there will be series resistances, and a small capacitance, the key is minimizing them to tame influence. In the end capacitance kills and is the most important, so the key is getting that one down. Also the resistance should not be too high either...

Looking at the datasheet for the CD4053 the capacitance when on is max 20pF, so that's good. The resistance is 240 Ohm max, 125 typical, that is good too. The lowpass cutoff will be 7*10^7 Hz, which is beyond the sonic spectrum. That means we're safe. And only with a crazy low imput impedance of the subsequent pedal/amp you will notice anything of the series resitance, right? Even when using 10 pedals of this type you should still be ok... So I guess it will perform just like a true bypass pedal in the end. Or did I overlook something?

 

[jimijames]

Re: Companies that are dishonest about true bypass.

I don't quite understand the cmos relay method of true bypass switching, but damn am I curious.

I will say that at even modest cable lengths (10' each side of the pedal board) the benefit of a buffer is tremendous, depending on the guitar (I have a seriously bright strat that needs some treble roll off to sound palatable).

Boss buffers are not great until you modify them. Most jfet buffers I quite like but IME the simpler the better when it comes to a buffer.

That out of the way I'd love to switch between effect and bypass with a boss momentary switch and minimal signal alteration in bypass.

 

[2manyguitars]

Re: Companies that are dishonest about true bypass.

I wouldn't think MXR would need to lie? They have built a pretty good name for themselves over the past few decades & they almost sell themselves? If anything you would think they would just not say nothing @ all & hope people just fig. they are true bypass because so many of their other pedals are??? I own 1 of almost every kind of MXR pedal in one form or another, they were all I'd use for years & as far as my dealings with the company itself, they were always very helpful & honest so perhaps just an oversight? I run a long pedal chain & I was experiencing some tone loss so I thought I get a buffer because all my pedals were true bypass @ the time? Instead of a buffer I ended up buying a E-H Soul Food, it can be switched from buffered bypass to true? So I keep it as my 1st pedal in the chain with the buffer on. Along with a buffer I also got a pretty awesome clean boost or O.D. pedal depending how I'm using it that day!!! There's nothing wrong with a buffered bypass pedal as long as you love it, it's nice to know what it is before you buy it though?

 

[uOpt]

Re: Companies that are dishonest about true bypass.

That was also my question. In the end it will, the question is just how much? Let's simply assume the transistors act like diodes when they are in bypass mode, that means there will be series resistances, and a small capacitance, the key is minimizing them to tame influence. In the end capacitance kills and is the most important, so the key is getting that one down. Also the resistance should not be too high either...

Looking at the datasheet for the CD4053 the capacitance when on is max 20pF, so that's good. The resistance is 240 Ohm max, 125 typical, that is good too. The lowpass cutoff will be 7*10^7 Hz, which is beyond the sonic spectrum. That means we're safe. And only with a crazy low imput impedance of the subsequent pedal/amp you will notice anything of the series resitance, right? Even when using 10 pedals of this type you should still be ok... So I guess it will perform just like a true bypass pedal in the end. Or did I overlook something?

But that means that, even in bypass mode, it is still an active element.

To ask differently, if you were to place a load capacitor to lower the pickup's resonance peak frequency before and after such a bypass, it wouldn't work after it, no?

 

[philthis]

Re: Companies that are dishonest about true bypass.

I bought an MXR Submachine fuzz pedal recently. While I love it, the box, websites, and demo videos advertise that it is true bypass, however the back of the user's manual says that it is buffered bypass in the specs.

When I tested the pedal in person, I discovered that it is not true bypass. I personally don't really care about whether a pedal is buffered or has true bypass, but some people do care.

And regardless of the timeless debate on the issue, I think MXR should be more honest about their products. Still an awesome pedal, though.

Have you guys ever caught B.S. like this from a guitar, amp, or pedal company? Do you think they're deliberately misleading people, or do you think they are just uneducated about their own products?

there's an old saying that goes.........I dont lie, I sell! pretty much sums that up.:scratchch

 

[Scott_F]

Re: Companies that are dishonest about true bypass.

True bypass is called a guitar cable plugged from amp to guitar with nothing in between!


Sent from my iPhone using Tapatalk

 

[Falloffthebonetone]

Re: Companies that are dishonest about true bypass.

there's an old saying that goes.........I dont lie, I sell! pretty much sums that up.:scratchch

It could just be an honest mistake. I've seen numerous companies sell something as one thing when it's really another AGAINST their own benefit all the time. It's as simple as not proofreading something very well before posting the info to a website or magazine or any variety of sellers. I remember one where the Gibson Nighthawk studio was advertised on the Gibson site as a mahogany body, but every other outlet said it was poplar. So I sent Gibson an email letting them know what was going on and sure enough they actually responded to me and clarified that it was mahogany and now that's what the outlets all say.

Another instance was when PRS released their SE basses and they both had the exact same descriptions even though they were very diffetent from each other. And that was just this last year or so, but again, it's fixed now. Maybe all MXR needs is a message and they'll fix the description too.

 

[MrTondo]

Re: Companies that are dishonest about true bypass.

But that means that, even in bypass mode, it is still an active element.

I guess not. At least not in the sense of having an active element in the signal path. To me it looks like it just acts like a small resistor and capacitance, just like any cable would. However the resistance is somewhat higher than normal. Too me that's it. I'm not completely sure though, I haven't looked into the internal workings of this device.

To ask differently, if you were to place a load capacitor to lower the pickup's resonance peak frequency before and after such a bypass, it wouldn't work after it, no?

I think it would... But again, I'm not sure.

 

[uOpt]

Re: Companies that are dishonest about true bypass.

True bypass is called a guitar cable plugged from amp to guitar with nothing in between!

A purely mechanical switch in a shielded enclosure is true enough by me.

 

[uOpt]

Re: Companies that are dishonest about true bypass.

I guess not. At least not in the sense of having an active element in the signal path. To me it looks like it just acts like a small resistor and capacitance, just like any cable would. However the resistance is somewhat higher than normal. Too me that's it. I'm not completely sure though, I haven't looked into the internal workings of this device.

I think it would... But again, I'm not sure.

Hmm, hold on. The capacitance is in series (the signal flows through it), no?

The cable's capacitance is parallel to the signal, it is a load capacitance.

If I wanted to test this, can somebody point me to buy this element somewhere?

 

[MrTondo]

Re: Companies that are dishonest about true bypass.

Hmm, hold on. The capacitance is in series (the signal flows through it), no?

No way, a pf range capacitance in series would be a highpass-filter that would only let all the really high frequencies through. The listed capacitance will surely be parallel as well. So it really is like a cable.

 

[uOpt]

Re: Companies that are dishonest about true bypass.

No way, a pf range capacitance in series would be a highpass-filter that would only let all the really high frequencies through. The listed capacitance will surely be parallel as well. So it really is like a cable.

Fair enough then. 20 pF would be acceptable as an additional load.

My Vox guitar cable has 0.41 nF, so that would be 5% more load.

 

[MrTondo]

Re: Companies that are dishonest about true bypass.

Fair enough then. 20 pF would be acceptable as an additional load.

My Vox guitar cable has 0.41 nF, so that would be 5% more load.

Yes, in effect it is comparable to using an extra patch cable, which also has something like 80pf/meter = 25pf/ft.

To fully do an honest comparison you'd also have to measure the resistance and capacitance of an average true bypass guitar pedal and compare. The 3pdt switch can have some capacitance, but the good ones usually do not...

 

[uOpt]

Re: Companies that are dishonest about true bypass.

Yes, in effect it is comparable to using an extra patch cable, which also has something like 80pf/meter = 25pf/ft.

To fully do an honest comparison you'd also have to measure the resistance and capacitance of an average true bypass guitar pedal and compare. The 3pdt switch can have some capacitance, but the good ones usually do not...

Now, a bit of load is OK with me.

I just can't wrap my head about the concept that impedance after this circuit is the same.

If you were to put load capacitors before or after this bypass, would they behave the same way?

 

[MrTondo]

Re: Companies that are dishonest about true bypass.

Now, a bit of load is OK with me.

I just can't wrap my head about the concept that impedance after this circuit is the same.

If you were to put load capacitors before or after this bypass, would they behave the same way?

To me that's basically asking, does putting it after or before a long cable make a difference. If yes, then yes it may (although it is more comparable to a short cable) make a difference.

I feel the thing that gets to you is: 'it's active'. But it is not really. In the end you can view it as a simple diode put in line with your signal, when bypassed. That's about it. In reality diodes have a stray capacitance and series resistance, so they are not theoretical, ideal diodes. That about the comparison between a real shorting switch = true bypass and a 'diode' short = this 'chip-bypass'. I hope that comparison helps a little bit

 

[uOpt]

Re: Companies that are dishonest about true bypass.

To me that's basically asking, does putting it after or before a long cable make a difference. If yes, then yes it may (although it is more comparable to a short cable) make a difference.

Still want to test

I feel the thing that gets to you is: 'it's active'. But it is not really. In the end you can view it as a simple diode put in line with your signal, when bypassed. That's about it. In reality diodes have a stray capacitance and series resistance, so they are not theoretical, ideal diodes. That about the comparison between a real shorting switch = true bypass and a 'diode' short = this 'chip-bypass'. I hope that comparison helps a little bit

OK, but that doesn't mix with saying that the load capacitance is parallel to the signal. How can a diode in series have a capacitance in parallel?

 

[MrTondo]

Re: Companies that are dishonest about true bypass.

OK, but that doesn't mix with saying that the load capacitance is parallel to the signal. How can a diode in series have a capacitance in parallel?

That's indeed where the comparison is not quite sufficient. In the end it functions as a diode with an added (non-used) electrode when in bypass mode. Hence the capacitance in parallel. The electrode is not 'functional' in the bypass mode, but it lead to some capacitance none the less.