A buffer is an active electronic circuit that keeps your guitar signal strong and preserves the frequencies of your guitar sound. If you have a good patch cord that's not too long, and plug directly into your amp, that is the purest sound you can get, and you don't need a buffer. But if you have long patch cords or a bunch of effects pedals, or a pedal with a weak output, a buffer can help get your sound back to the pure tone you are looking for.
All a buffer is, is something that takes your signal and outputs it with a low impedance, to drive it strongly into the next thing in line. All pedals have output impedance when on, most are low so they are considered to have "good buffer". Some like a Phase90, Blues Breaker, Ross compressor, etc have high output impedance and cannot drive your signal well, causing a dull sound. Adding a "buffer" after these pedals will help.
All patch cords or Guitar Cables have some capacitance to them, especially cheaper cables like cables with molded ends. This acts just like the capacitor on your guitar's tone knob when you turn it down some, and rolls off the high end. Really bad cords can suck away too much of your tone, even mids, and should probably be replaced though a good buffer might make them usable. Some pedals, like old wahs, big muffs, etc also suck a lot of your tone away as they keep the circuit connected to your signal even when they are OFF (not true bypass, or buffered bypass). Certain pedals as mentioned earlier have a poor output impedance (too high) and even when they are ON, the signal will get loaded by cables or other pedals after them. You can test and find these types of pedals by using long cords and turning a buffer on and off after them - the buffer should do nothing on most pedals, but some will sound much brighter, clearer, and louder with a buffer after them. Those pedals are helped with a buffer following them.
Some pedals have BUFFERED BYPASS, and when OFF your signal goes through active electronics and is kept strong. Ibanez Tube Screamers, Boss delays, etc have pretty good buffers. One or two buffers or buffered pedals is good in your signal path, but you don't want too many as each one can change your tone a bit, and can rob a little of the presence and feel of your guitar, especially some pedals with poor sounding buffers. So replacing extra buffered pedals with true bypass pedals, modifying them for true bypass, or putting them in a bypass loop is a good idea.
One pedal you can use for a great buffer is our ARDX20 dual analog delay- if you always leave it on, that could be the only buffer you need. If you need NO DELAY at all, just turn the delay level down all the way on one side and that side will just be a buffer. I find my ARDX20 is a great way to test pedals and cords - turn the DELAY LEVEL down all the way (for just dry sound), and turn the delay on (buffered) and off (bypass). If you hear an improvement when ON, then your cable or pedal being tested is hurting your tone.
Some pedals like the vintage circuits of a Fuzz Face or Rangemaster won't work well with a buffer or buffered pedal before them. The buffer won't let them do their "clean up" magic and can make them sound brittle. Put buffers or buffered bypass pedals AFTER these.
Volume Pedals are another item that can be helped with buffers. If you use a passive style volume pedal with high impedance, like the Ernie Ball 250K pedal, it will work great with just your guitar plugged in and won't suck much tone. But when you add buffered pedals in front of it, the sweep can get strange, making it hard to get the desired volume setting. In that case, the 25K ACTIVE Ernie Ball pedal will have a better sweep, but it NEEDS to have a strong buffer before it or it will REALLY hurt your tone. So I think the best setup would be the 25K volume pedal and a good buffer that's always ON before it. We can build our buffer into one of these volume pedals to kill two birds with one stone, and keep your pedalboard size under control. With the buffer, it will no longer work as an EXPRESSION PEDAL.
Here is the buffer inside the Ernie Ball VP Junior 25K 6181 Volume Pedal. The pedal is apart slightly so you can see the board. The power jack we add to run the buffer is between the jacks.
We can also put our buffer in the Boss FV500-L stereo volume/expression pedal. Normally we put it in one side (Input 1/Output 1), which is the side that has a TUNER OUT jack. We can add a second buffer to the other side if you need stereo buffered signals. With the buffer, it will no longer work as an EXPRESSION PEDAL. You can see the added power jack on the right side. We can also put it on the left if you specify in your order comments.
We can make most other pedals have BUFFERED BYPASS if there is room inside, and they are hand wired. Our King of Tone and Prince of Tone have room in the battery compartment so we are offering them with a buffer option or we can modify yours. Some pedals like the KOT can sound better with a buffer after them. Most people run a delay pedal or reverb after their KOT so that is usually enough. But if your KOT goes direct to your amp, with a long cord, the buffer will certainly help when the KOT is OFF and may help even when the KOT is ON. If you get the 4 jack option on the KOT, and use all 4 jacks to split the KOT into two separate pedals, the buffer will be on the left side of the pedal. Our MODFORM has the "add a buffer" option for sending in your pedal, for example a volume pedal, KOT, POT, or other hand-wired pedals.
Most buffers on the market are the simplest opamp circuit possible-one opamp stage with unity gain, just a few resistors and capacitors are needed. Even the KLON buffer is like this. Some are one transistor or FET with some similar simple power and coupling circuit. These do the job of having a high input impedance and a low output impedance to drive your signal to the amp nice and strong. But many cheap buffers like that just don't sound and feel the same as the original best tone described above - a good cord direct into your amp. Some buffers can send too much high end through, and sound brittle or HARD, not a nice feel. Many great sounding pedals like tube screamers, etc don't run your signal directly into the op-amp, instead they use a transistor input buffer. We use the same transistor as an old tube screamer on the input of our buffer, with the same input impedance of 510K. Most buffers use a higher input impedance but that can sound too bright and tinny - not like the sound of plugging straight into your amp with a 10' quality cord, which is what we tried to emulate. We also use the tube screamer's JRC4558D opamp later in the circuit for a warm but clean unity gain amplifier.
Here's a note I got from a customer:
Thanks for making a terrific buffer. I recently built a small board and bought a ***** (which is based on the Klon Centaur buffer circuit). Ughh...it sounded awful, everything sounded hard & sterile no matter where I placed it in the chain. I preferred the darker unbuffered signal to that.
Yours sounds nice though, brings the sparkle back, doesn't do weird stuff to the bass. The amp is still juicy sounding. Didn't realize how much of a difference various buffer circuits make.
There is a great article on buffers on the DIY site AMZ muzique.com where Jack says,
"An opamp is an even better buffer amplifier, though many believe they are somewhat colder sounding and more sterile than the transistor versions. The opamp gain is exactly unity and the output impedance is quite low; typically measured in tens of ohms instead of hundreds as with the transistors."
We use both the transistor on the input and the op-amp on the output for the best of both worlds - nice silky tone and strong output.
Our original Analog Delay, the ARDL20, had buffered bypass and customers raved about how great the buffer was in that pedal. While on or off, it would keep your signal strong and sweet. We use the same buffer circuit in our ARDX20 dual analog delay but it has true bypass, so when OFF there is no buffer. But you can use an expression or volume pedal in the FX loop to kill the delays if you want just the buffer, or turn the level down.
This circuit is much more complex than a normal buffer but we feel it's worth it as it gives a more natural feel and balance, warm with a touch of compression and natural frequency response but without changing your tone. We want it to sound and feel just like a 10 foot high quality patch cord direct into your amp. A virtual cable!
We can make this buffer in any of our boxes, with almost any feature you would want. The smallest and simplest is the tiny box with power jack and no switch or LED, also no room for a battery. It does have room for a second power jack if you want. We can put the jacks on one side on the tiny box if that works better for you.
We can also use the MXR size small box which will fit a switch, LED, Battery, etc. We can build them into any of our switchboxes, might be nice to get a TUNER MUTE SWITCH to get your tuner and it's cable out of your signal path, with a buffer to buffer the rest of your signal. See our SWITCHBOX PAGE for some samples and more info.
All Analog Man buffers are hand made in the USA.
For ordering, options, and pricing, see buyanalogman.com
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