Over the past 10+ years I have been on a constant search for the ideal acoustic guitar preamp pedal when playing out without an amp. Unlike electric guitar or bass guitar effects pedals, there are not THAT many of these on the market, especially from reputable manufacturers. I think this may have something to do with the fact that they are actually quite difficult to design!
An acoustic instrument produces a very fullrange signal in comparison to an electric guitar or bass, and getting this to translate well through a pickup/preamp system has challenged engineers for decades, to the point where using a pickup is still seen as a concession to the exigencies of live performance. No self-respecting recording engineer would ever track an acoustic instrument purely using a pickup system – a microphone would always be employed in the first instance.
Fishman and LR Baggs have ruled this arena for decades, alongside Taylor and Takamine who produce their own proprietary pickup systems. This section contains my thoughts on some of the pedals I’ve used over the years, together with buying links if you would like to support my work.
Released in late 2016, the AD-2 is one of the more compact acoustic guitar preamps available. It follows the familiar Boss form factor, being 73mm wide, 129mm deep and 59mm tall. This means that it will fit on standard pedal boards alongside your other floor wizardry, and gives it an advantage over its numerical big brother the AD-3, which takes up significantly more space. The pedal features a notch filter, ambience and acoustic resonance effects and a balanced line out in addition to the standard unbalanced output, making it the simplest pedal of this type available from Boss.
Input impedance is 10 M ohms which means that the pedal can accept passive piezo pickups directly with no need for an additional buffer in the signal chain. This would also allow the pedal to act as a backup in the event that your onboard preamp were to go down. Of course magnetic soundhole pickups will work fine too. The pedal features a buffered bypass which means that it will not pass signal if the batteries fail completely, but in my experience the pedal knows when the juice is about to run out and stitches off the effects in order to keep the buffer alive. Nevertheless an external power supply is to be preferred if at all possible. Battery life is stated to be 6 hours of continuous use. Continue reading