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Forum Home > Layout Gallery - GuitarPCB Build Documents, Mods and Tips > 3PDT Buffered Bypass Footswitch

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This is the Brand Fabricated Buffer that solders directly to a 3PDT Wiring board and can be added to any circuit with ease.

This is for the Buffer Board only. 3PDT Foot Switch is not included.

Footswitch is available at Mammoth Electronics.

3PDT Buffer Build Instructions

Also Read This: On- Board 3PDT Wiring

This will allow you to benefit from all the advantages of the Silent Tuning Buffer Board without the Tuner Output and in a small footprint that attaches directly to your 3PDT Footswitch leaving plenty of room for any circuit above it!

Because you connected a fairly long cable (15ft. or more), you lose even more of the actual signal and it doesn't appear across the input of the pedal. You are now losing a good amount of the signal from those expensive pickups you bought. . . The story gets better for low frequencies, but worse for higher frequencies. This configuration is called a low pass filter, because low frequency signals pass through but higher frequencies do not. You really don’t want this if you want to preserve the fidelity of your original guitar pickup signal.

Question time, where is it better to put a guitar buffer, before or after a long cable? The answer is before. The reason is that if you have a low impedance of the capacitance of the cable then it is in parallel with the input impedance of whatever is after it (remember from before). So, even if you have that high impedance guitar buffer, effectively the impedance is low and you will lose your signal. But, if you have the guitar buffer pedal before the cable, then the low output impedance of the buffer will be able to drive the cable and the input resistance of the next pedal or amp in the line.


In Guitar PCB fashion it is also moddable to suit your own tone even further.

As shown in the Picture this will even fit into a 1290 size pedal enclosure.

PDF Diagram of Pedal Chain

Pictures with Details why you may need one of these in your rig.

An additional use of this circuit courtesy of Tonmann:

This will buffer your guitar signal when it is connected to the effects chain or directly to your amplifier - an added advantage is that you can bypass the effects chain instead of trying to turn two or more pedals off at the same time.

The normal method of connection is guitar to the input, FX send to the input of the first pedal in the chain, output from the last pedal in the chain to FX return, output to amplifier.

Of course you are not limited to this method of routing; if you want the ART Tube connected permanently you would route the output of the Tremolo to the FX return, the output of the board to the input of the ART Tube and the output of the ART Tube to your amplifier input..

Hope this helps.

An extension of the previous extension by Tonmann:

I've recently had some questions concerning the 3PDT Buffered Bypass Footswitch so here are a few ideas.

Diagram A - this is very much the standard application where the Buffered Bypass Switch (BBS) replaces the 3PDT Wiring Board, instead of true bypass switching we now have a buffered signal feeding the input of the circuit in effects mode and a buffered output signal feeding either a second pedal or the input to a guitar amplifier when in bypass mode.  This method would normally be used when you are using just one pedal or you always have the pedal as the first effect in a chain.

Diagram B - Instead of putting the BBS and effect in one box, the BBS housed in it's own enclosure.  This is useful if you are constantly changing the first pedal in your effects chain.  Another advantage is that you can use commercial pedals that are either true or non-true bypassing as the first effect and always have a buffered signal feeding a second effect (or your amplifier) when in bypass mode.

If FX1 is non-true bypassing you would use the BBS to switch between effects and bypass mode.

If FX1 uses true bypass switching you can use either the bypass footswitch on the pedal or the BBS to switch FX1 between effects and bypass mode.

Diagram C - This time the BBS is connected to a chain of pedals, normally you would use the bypass switch on each pedal to switch it in and out of the chain, if you want to switch all of the pedals to bypass at the same time you would use the BBS.

Another benefit of this system concerns live playing.  Installing a battery and an external power supply jack for the BBS is certainly a good idea - if you are one of those people that has a large pedal board with an external power supply and the power supply (or one of the pedals) dies during a concert you would only have to remove the external power supply from the BBS so that the battery kicks in and then switch the BBS to bypass - OK so you might have to finish the set or song without your pedals (or until you or your guitar tech can figure out the problem) but at least you will still have a buffered signal to your amplifier.

This going to be a very rare occurrence and has only ever happened to me once - I wish I had a BBS at the time.

Diagram D - just an extension from Diagram C.  This is a useful configuration if you need to switch two effects at the same time.  Switching two pedals simultaneously is hard enough, even harder if one of them is a Wah or Swell pedal. This configuration is not limited to the first two effects in a chain it can be placed anywhere, nor are you limited to just one BBS if you need more.

The above shows how to wire the BBS in its own enclosure.

Hopefully the above provides some food for thought.

Some expected IC1 readings:

1-0.15  8-0.00

2-4.24  7-8.51

3-4.00  6-4.24

4-0.00  5-0.15

October 30, 2012 at 1:50 PM Flag Quote & Reply

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