[313] Buffers Before Fuzz

Date: May 20th, 2009 | Comments : [8] | Categories: DIY.

FuzzfaceIf I had ten cents for every time that someone posted on a guitar pedal forum that it was bad to place a buffer in front of a fuzz pedal, I could go to Starbucks every day for a month.

First, they is no universal agreement as to what specifically defines a fuzz pedal. Even the effects manufacturers are not in agreement about it. However, most everyone agrees that the fuzzface design is indeed a fuzz, and that placing a buffer in front of one will change the sound. I concur.

I think we can all agree that a buffer will “change the sound” of a fuzzface but that does not automatically make it bad to use a buffer before it. Consider this, when a wah pedal driving a fuzzface gives trouble with oscillation or other disruptive sounds, what do the experts recommend? A buffer… a buffer after the wah and before the fuzzface.

Furthermore, one of the most revered boutique fuzz pedals in the Lovetone Big Cheese, the design of which includes an opamp buffer driving a fuzzface circuit! Does it sound bad? Not by the vast majority of its reviews.

So what is going on? My initial thought is that the warning about buffers before fuzz originated with players who like to roll back on the guitar volume to get some interaction between the guitar pickup and the fuzzface. It is true that a buffer interferes with this interchange, and I could see how some guitarists do not like that change. I don’t twiddle the guitar volume so it never bothered me.

After some thought on the design, it seems that another technical factor is involved. The first transistor of the fuzzface is the gain stage and the second transistor is a buffer which is providing the feedback to the inverting input of the first transistor. This is actually forming a crude inverting opamp stage, in which the guitar pickups impedance is acting as an input resistance. It is also the reason that different guitars can sound radially different with fuzzface pedals since their pickup impedance may vary greatly from each other. If a buffer is driving the input stage with a different impedance, and that can make it sound different.

Also, a Big Muff is a fuzz pedal and a buffer driving it will not have much impact on the sound. There is too much internal gain and the cascaded clipping stages will swamp out any minor differences caused by the driving source.

Does a buffer before a fuzz change the sound? Sure it does… a buffer will change the sound of almost any pedal it is driving but that is not automatically bad, even with a fuzz! It might make it thin or cutting but it might also give more clarity to your distortion sound. There is no way to know until you try it.

‘No buffers before fuzz pedals’ is one of the often repeated Internet myths that should be busted. It can sound good or bad, and much depends on you guitar, amp and the other pedals on your board. As always, let your ears be your guide!


8 Responses to “Buffers Before Fuzz”

[745] Todd Smith Says: 7:26 pm, July 12th, 2009

Great info! Love your site. I’m going to add you to my blog roll.

[774] rboyo Says: 10:32 am, August 20th, 2009

What’s a good solution for a buffer in front of a positive ground Fuzz? Can you make a buffer Positive ground?

[793] Chip Audette Says: 8:26 pm, September 22nd, 2009

I built a fuzz with an op-amp buffer in front that was switchable. That way, I can go back-and-forth between buffered and not.

I found that with the humbuckers, I like it buffered. With single-coils, I always run unbuffered.



[943] JL Says: 8:48 am, February 11th, 2010

I have built several types of buffers from this site as well as Beavis Audio. I’ve put them before my board, after my board, and before AND after. End result – let your ears be your guide. I personally like the “Plon Fentaur” buffer running before my board (I use single and humbucker guitars into tube amps). Love what it does to my overdrives, my fuzzes…all my pedals. Great clarity, harmonics.
LOVE the site. Thank you very much.

[1322] Jay Doyle Says: 10:00 am, October 6th, 2010

If one looks in old textbooks you will find versions of this circuit, but with a resistor in series with the input transistors’s base. The gain of the circuit is the 100k feedback resistor divided by the input resistance – so you are indeed correct when you state “the guitar pickups impedance is acting as an input resistance” and therefore each guitar sounds different. Using a buffer cranks up the gain of a FF stage because the gain is then super-high with the 100k divided by a few tens (or so)ohms.

It may also be helpful to remember that the feedback resistor from Q2 emitter to Q1 base is the same as if the resistor was from Q1’s collector to Q1’s base.

[2491] Paul Says: 1:19 am, December 11th, 2011

Love this kind of info and w some level of knowledge without being a parrot of typical bad pass-ons. Buffers and by pass are a confusing mess and I hate the “try it and see” as if our ears serve as the ultimate judge. They don’t and there are rules and things that sound bad. A wah is a filter and filters sound better before dirt. I put my CAE bypass wah before my main board Radial buffer pedal and that seems to do the trick for anything to follow. I use Wampler and nothing vintage. Wah, buffer, all bypass, final chain tube buffer circuit in my Ibanez tube unit.

[2855] Doron Says: 6:33 am, April 20th, 2012

Well one thing I’ve learned recently is that a Treble Booster which can be considered as a buffer, can really do magic on a Germanium Fuzz Face pedal. The fuzz sounds smooth and warm without the booster, but once you kick it in you get some extra brightness and definition which was not there before. The booster, of course, is set not low boost gain and can still give you dynamic guitar knob roll off.

[4958] Paul Says: 11:30 pm, November 6th, 2013

Seems to be another pedal board weirdness and conflerict of information. If you look at the Fulltone Clyde Deluxe wah it has a special output buffer option that is designed to make the wah sound right in front of high gains and fuzz, so no buffer, Fulker designed a special one for his wah and it sounds great, the buffer is off when the wsh is off. So what does one do, hell if I know. How about compressor before or after wah?


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