Bypass Box

[doitle]

This just came to me and while I'm sure it's not a new idea I was just wondering if anyone has seen anyone selling these or using them. I've seen a few times where people wanted the tone retaining characteristics of a true bypass configuration but either could not or didn't want to modify their pedal either for warranty or because it was an antique/historic pedal.



I'm not sure if this cryptic napkin drawing will get anything accross but my idea is just make a small enclosure with a DPDT or 3PDT switch depending inside. Then wire that for true bypass. Then you run your guitar signal chain through the box and you also run the effect pedal into the box basically true bypassing the pedal without actually modifying it.

-------------------------------------- <--- Guitar Signal

    \----------[Effect]----------/                     BYPASS

----\                                   /------ <--- Guitar Signal
      \---------[Effect]---------/           
                                                               EFFECT ENGAGED

You would leave the effect engaged all the time and then switch the bypass box to actually pass the guitar signal to the effect. This way effects that normally suck out your tone would have no effect when they aren't being used.

Thoughts?

[darron]

yeah. these are always popping up on ebay. and you can have the advantage of putting a few pedals in the same loop too. put in pull down resistors and and make sure you use a grounded input on bypass.

[Rodders]

Interestingly enough (or perhaps not) I just built something similar.

I wanted a tuner that I can use on stage but didn't cost £50+ like the Boss TU-2 or Korg Pitchblack. So I paid £10 for a Korg CA-30 tuner and built a little box which lets me switch my signal to it. Someone suggested I make it into a true loop so that I could use it for exactly what you suggest. So, with the addition of one more socket and a bit of wire I did just that.

I added a little customisation to mine too - my tuner has no backlight so I added a socket where I can plug an external LED in which I can position above the tuner to provide enough light to view the screen. Only thing I haven't managed is to switch the unit on with the footswitch. I opened it up but the on/off looked complicated!

[Rodders]

yeah. these are always popping up on ebay. and you can have the advantage of putting a few pedals in the same loop too. put in pull down resistors and and make sure you use a grounded input on bypass.

I meant to ask a couple of questions:

1. What is meant by pull down resistors?
2. What is grounded input on bypass? The description suggests connecting the input (tip) to ground on bypass mode! Really?

[darron]

yeah. these are always popping up on ebay. and you can have the advantage of putting a few pedals in the same loop too. put in pull down resistors and and make sure you use a grounded input on bypass.

I meant to ask a couple of questions:

1. What is meant by pull down resistors?
2. What is grounded input on bypass? The description suggests connecting the input (tip) to ground on bypass mode! Really?

1. you're not sure what the input and output of the pedal you are looping are going to look like, so on the "send" and "return" jacks put a high value resistor of 1m or more between the tip and ground to discharge the input and output caps and to limit the charging effect. this will help to get rid of some pop.

2. you bet. when the effect is in bypass mode have it's input (tip) shorted to ground. it's not a good idea to have the signal just floating, especially for high gain units which might self-oscillate.

Here's a quick readup I made a few years ago: http://www.dazatronyx.com/support/true-bypass-technique.pdf


edit: I actually use a different configuration on my switches now for wiring convenience, but that works just as well and you can do it however you want. ie you can swop any of the verticle rows around as long as they all make the same connection.

regardless, the text alone should give a better explanation so that you don't need the diagram.