what's a buffered bypass?

[allicio]

can anybody tell me what a buffered bypass is? I sent an email to dunlop to ask if the new black label chorus by mxr is true bypass they said it wasn't but was a buffered bypass. can anybody tell me what this is and is it a good thing?

 

[fuzzo]

you have 3 commun ways of switching. Electronics bypass (thing you can find in Boss/digitech/danelectro, cheap pedals) , tru bypass (classique, used in boutique pedal or brand like electro harmonix or MXR/dunlop), and with "relay'" , system used also in amp for the channel switching. Not really used in pedal but I know Frantone does that.

Well, buffered bypass means you have a buffer at input and ouput linked to a momentary switch which makes contact to ON/OFF the effect . Boss pedals are perfect exemple of that kind of circuit. More complexe than a regular tru bypass but really cheap compared to a 3PDT switch.

It exsits also, in old pedals, a mix with buffer and bypass. the bypassed signal is taken after the input buffer but can caused some "tone sucking" (like in Crybaby for instance) .

 

[allicio]

thank you so much for the reply. its not very often you see something that's more complex yet cheaper to produce. I take it by your tone sucking comment that the pedal will alter the signal for the worse which is a shame as I was hoping I could get this pedal as a cheaper alternative to the full blown mxr chorus which is true bypass thanks again for the info

 

[BobChuck]

http://www.moollon.com/techntip/buffer_e.asp

 

[stinkfoot]

"Buffered bypass" simply means there's a buffer stage (1:1 gain amplifier stage) in the bypass signal path. It can be applied to any type of setup - as long as the buffer sits in series with the bypass path (so the bypass signal passes through it), the bypass is buffered.

A Boss pedal has electronic switching, and since that system requires buffer stages, of course it is buffered
Other manufacturers sometimes stick a buffer stage on the input to the circuit, but runs a passive bypass signal in parallel to that. This is often called "hardwire" bypass, and the Crybaby and many of the MXR pedals are prime examples of that. These pedals are not buffered, and can cause tone loss due to the parallel signal path.
There are a few that have the buffer stage in front of the switch, so it's in series with the bypass path instead, and those would be buffered - regardless of if the actual effect is true bypassed [MI Audio Boost'n'Buff] or not [Klon].

/Andreas