MI AUDIO BOOST N BUFF v3NEWEST AND LATEST v3 BUILD with the added 3 way toggle switch providing boost options for FULL, TREBLE, or MID. Now the MI Boost and Buff is more versatile than ever!
I wanted to create one pedal that would perform all of these functions. But this then led to a whole bunch of questions.
– What should the input impedance of the buffer be?
– Should it be variable?
– Should there be input and output sensitivity controls?
– Should the control for switching from flat to treble booster change the gain as well?
– Instead of a switch, should there be some kind of control to morph from flat to treble?
– What about dedicated low and mid controls?
– Should the low and high controls be roll-off controls or shelving EQs?
– Active or passive?
– If we add all this electronics in there, will it get too noisy?
My initial prototypes were very complex (as you can gather from this rather disturbing insight into my thought processes). And then one day, a design of stunning simplicity and utilitarian elegance came to me. The Boost ‘n’ Buff…here it is!
Bypass Mode/Buffer: In bypass mode, the Boost ‘n’ Buff acts as an ultra high input impedance/low noise buffer. In fact, the input impedance is approximately 5Meg. With such a high input impedance, your guitar pickups don’t need to deliver a lot of current in order to reproduce their full natural bandwidth. You can drive cable lengths as long as you like without sacrificing tone, and due to the ultra low noise design, you can use the Boost ‘n’ Buff out the front of dirt pedals or high gain amps without worrying about introducing any significant noise.
So what’s different about this buffer and the buffer you’d find on mass produced pedals? Well, the primary role of a buffer on a mass produced pedal is not to ‘rescue’ your guitar tone from degradation, but rather to drive the low quality transistor based switching system. The input impedance of these buffer circuits are thus designed not to keep all of the top end sparkle of your guitar tone. In some cases, the input impedance of this buffer is as low as 200kOhms, which is 25 times lower than the input impedance of the Boost ‘n’ Buff circuit.
By adding the Boost ‘n’ Buff in your signal chain, especially near the front of your effects, you’ll notice that in bypass mode your guitar signal will have a bit more sparkle and top end detail. It’s not that there are any special EQing ‘tricks’, but rather that the Boost ‘n’ Buff is faithfully reproducing all of the frequencies that are coming out of your guitar. Your tone will feel a bit more powerful, with more punch and almost as if there’s more dynamic range and ‘sustain’ (although these are not the right words to describe it). You’ve got to try it out to feel what I’m talking about.
Flat Booster: In the first half of the volume sweep, the frequency response of the Boost ‘n’ Buff is flat. This provides you with about 15db of flat boost before the frequency response of the pedal starts to become more treble booster-like. This is perfect for solo volume boosts. The one thing to note is that if you’re going to use digital effects in your signal path, I’d suggest putting the Boost ‘n’ Buff after the digital effects to avoid overloading the A/D converters.
Another interesting application is using the Boost ‘n’ Buff in the FX loop of an amp to act as a secondary volume control. Since it has ample headroom, line level signals are not a problem. So even if your FX loop is line level, you can still get quite a bit of boost using the Boost ‘n’ Buff. This way, your FX loops can also double as a solo volume booster as well as a standard FX loop. By putting the Boost ‘n’ Buff in the FX loop, you can use it to boost the volume of an overdrive channel. If you’re using the overdrive channel of your amp, then putting any booster between the guitar and amp will just increase the amount of distortion as opposed to increasing volume. By putting it AFTER the preamp (in the FX loop), you can achieve volume boosting without affecting preamp tone.
Treble Booster: Once past the half way point, the mid and high frequencies start to climb faster than the low frequencies. At maximum gain, not only do you have an amazing amount of boost (approximately 35db), but the frequency response is perfectly tailored to driving a valve amp. It’s literally like hot-rodding your amp with an extra tube stage. Also, with the 18V headroom, your sound will be ‘cleaner’ going into the amp, so that there’s less colouring from the transistor.