“Do I need a buffer?” It’s one of the most confounding questions on guitarist’s minds on the Seymour Duncan User Group Forums and elsewhere. Truth be told, there is no easy one-size-fits-all answer, but there are a few simple things you can try to figure out what your rig needs, and what it doesn’t.
Before we get down to answering the buffer question, it’s important to know what a buffer is and what it’s commonly used for in an electric guitar rig. In the electronics world, there are many kinds of buffer. The type guitarists are concerned with is more accurately called a “buffer amplifier” and it’s used to convert a high impedance signal to a low impedance signal. Passive guitar pickups (e.g. your garden variety single coil or humbucker) produce a high impedance signal, which is vulnerable to interference and has difficulty traveling down long cables intact. The job of the buffer is to take this weak, high impedance signal and drop the impedance, producing a strong signal that can push its way down long cables and big pedal boards.
The buffer amplifier is a very simple amp circuit similar to what you might find in an overdrive or fuzz pedal, except it’s set at unity gain (i.e. no change in distortion, tone, or volume). The ideal buffer lowers the impedance of your signal without any change to your tone. When people talk about a “transparent” buffer, this is what they’re describing.
So, why do we want a buffer? The simple answer is that the world is a dangerous place for high impedance signals. They are vulnerable to RF interference (anything from the rehearsal room’s fluorescent lights to that giant fan your singer uses to blow his hair back) and cable capacitance (the treble loss induced by long and/or low-quality cables). The longer your cable runs – and the more complex your rig – the more likely your tone will be degraded by the time it trickles into your amp.
If you like to use long cables, pedals or multi-effects units between your guitar and your amp, try this test. Get a short (six feet or less) cable of decent quality and plug your guitar directly into your amp. Dial up a nice clean tone, strum a few chords, and play a few single note lines. Now plug into your usual cables and effects, make sure all the effects are turned off (bypassed), and play again. If you didn’t notice a difference (or if things sounded better), congratulations: you don’t need a buffer.
If, however, you noticed decreased definition, treble, dynamics, or maybe even lower volume compared to the short, direct cable, you might want to look into a buffer for your pedal board. The high frequencies are the most vulnerable to signal loss, so if you’re finding yourself not cutting through the mix, a buffer might be the answer.
That said, there are other reasons you might be experiencing signal loss, chief among them are your effects pedals themselves. Some pedals, typically very old designs or cheap units, can drag your tone down, even when bypassed. In these cases, depending on how the pedal is designed, a buffer may not do much good, but it won’t hurt. This is a complicated topic, and I’ll discuss it a bit more in a future post.
On the other side of the coin, your pedals may also be helping to strengthen your signal by keeping the impedance low. Many pedals and multi-effects units have built-in buffers; some are on even when the pedal is bypassed. Think of this as the pedal manufacturer giving you a bonus buffer with your effect. If you noticed no difference between your normal rig and the short, direct cable, you might be benefiting from a good buffer in one of your effects.
If you’ve reached this point and decided you want to try a buffer in your rig, you might be wondering where to go from here. Buffers aren’t like normal guitar pedals; since their effect on your tone isn’t an in-your-face obvious thing, it’s not always easy to know which one is working for you. In general, there are two approaches:
- Buy an off-the-shelf buffer unit.
- Build a buffer yourself, or have someone build one for you.
The first option is the simplest, of course. There are quite a few good stand-alone buffers out there. That said, a buffer amplifier is a very simple circuit, and a great choice for a novice pedal builder. Check out Jack Orman’s excellent article on how to build a transistor-based buffer for some more info.
Once you get your buffer unboxed or soldered up, the next question is where to put it. Some prefer to place the buffer first in the effects chain, while some find it does more good at the end. I personally think it makes the most sense to have the buffer come in first on your pedal board, since it can raise the impedance for all your pedals that come after it.
There are a few reasons why you might want to have it further along though. A Fuzz Face (or any of its many clones) is an example of a pedal that reacts poorly to a low impedance signal, so if you have one of these you should definitely not place a buffer in front of it. Also, if the main source of your problem is a long cable between the pedal board and the amp, putting the buffer last is best.
This is a complicated topic, so please do comment if you have any questions. If I can’t answer your question, maybe someone else can. If you have a buffer in your rig, I’d love to know your thoughts about it. Let’s shed some light on these mysterious devices!