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Hello, I have questions about a Buffer circuit. There’s a few PCB here that use the word Buff, whatever… Buff n Blend, Silent tuner w buffing circuit, 3rd stage boost and buff and the 3PTD buffer board. How are we using the word buffer? As if to say that I have a few noisy builds that are perfectly quiet when a boss pedal is put before it. I am told the Buffered Boss pedal is eliminating the noise. Would using one of these Buffers do the same? I really don’t know, just some simple word associating, and maybe I find out what these buffer pcb’s do and if they might be the fix to my problem.
Robert – from what I know pedals and long-run pedal chains, the signal can get “thin” and/or loose some its “brilliance” due to the combined capacitive loading of shielded cable in a true-bypass environment. A “buffer” is designed to push the signal thru those cables and overcome the capacitive loading therein – while re-establishing a specific impedance.
Conversely, too much “buffering” in a pedal chain may lead to loss of signal level (likely because the impedance gets too low with too many) and/or other unpleasantness. Stinkfoot has a decent article on buffers with a focus on Boss buffers. Premiere Guitar also has a “Crash Course on Buffers” article that may help.
And not all buffers are transparent, (as noted in the Stinkfoot article), and can color the signal. GuitarPCB buffered projects in the “Mod Boards” section are all JFET based buffers and rather transparent.
In front of some pedals, a buffered pedal in front of it is a good thing. For others, it may actually cause an irrecoverable tone loss/change. There are so many different pedals with so many different input and output impedances that it take either a lot of experimentation to find what pedals work best in a specific in a chain – OR – it takes a good bit of reading and/or testing the pedals used in a chain to know before what their input/output impedances are before assembling the chain.
Simply put, a buffer takes a hi-impedance signal and converts it to a lo-impedance signal. When changing the impedance from high to low, the buffer is restoring the signal flow to be the strongest it can be. Think of the signal like water running through a hose and a buffer is what keeps that water from getting caught in the “kinks.” Buffers help strengthen the guitar’s signal so it stays strong throughout the “hose” all the way to your amp!
Noisy builds are often noisy without a buffer in front of it when there is a great enough impedance mismatch between the pedal and what is feeding it.
Hello there, I just saw this. I had a big issue with high gain preamp pcb’s. I had no idea they were so noisy with a high frequency squeal and all kinds of unwanted noise. On my test bench, I play prerecorded loops through a boss pedal. The preamp builds sounded amazing, until we plugged it in at home … No buffer in front!. All attempts to reroute and isolate audio from power wires helped a little bit, but wasn’t half as quiet when a boss pedal was in front of it. Might a buffer pcb in front of the preamp quiet the circuit? I want to say yes, based on the above stated closing line.
“Noisy builds are often noisy without a buffer in front of it when there is a great enough impedance mismatch between the pedal and what is feeding it.”
So it should, as long as the unwanted noise is in fact due to mismatched impedance… Yeah? I will likely build one and see what happens on a noisy build.
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