This pro-grade preamp allows you to combine the realism of a high-end microphone (condenser or dynamic) and a piezo/passive transducer. It's also among the only preamps with these features that has been designed specifically around the needs of double bassists!
Each channel features its own semi-parametric EQ, allowing you to dial in specific frequencies to boost or cut (a key feature for both tone-shaping and feedback resistance!) and independent volume controls for the DI output and amp output allow you to adjust your volume onstage without throwing the soundman a curveball.
Manufactured in Italy with quality components like Neutrik jacks and an integrated toroidal power supply (no wall wart plug!), this is one seriously well-designed piece of kit. And with a small footprint, and a weight right around 2 lbs., it travels light.
The Acoustic Box Live is clearly designed to give you the features you really need, without a lot of extra stuff you don't.
The microphone channel includes standard 48v phantom power, to coax the best performance out of your microphone by powering it efficiently. It also provides a notch filter, a very useful feature for locating and "dialing out" troublesome feedback frequencies. Its semi-parametric equalizer control can be adjusted from 100Hz to 1.8 KHz, so you can tweak the midrange to get just the right tonal character. And the shelving low-pass filter reduces the mid-high frequencies by up to 6dB, a design feature that the manufacturer suggests can substantially reduce feedback from the mic at higher volumes (as when playing with a drummer) without compromising the sound quality.
The pickup channel features a 5 megOhm impedance, which buffers the high impedance of piezo-based pickups, a key feature for getting the fullest, best tone from them. It also has a semi-parametric EQ (360 Hz - 4KHz) for dialing in your pickup's "sweet spot." And if the microphone and pickup aren't blending quite "right," the phase switch on the mic channel can help align the phase of the pickup and mic better - and might help with feedback as well.
Each channel has its own level control, so you can create just the right mix of microphone and pickup. The blend you've created is then sent to the "master section," where you have further control over the overall tone and volume. A very powerful three-band Master EQ provides more opportunity to fine-tune your sound, and a master phase switch can help you get the right phase alignment between onstage speakers and your instrument (more tonal and feedback help!) A master mute switch, for when you need to take a break (or silently tune) and separate volume controls for the amp output and the XLR Direct Output (for sending your signal to the house sound system - you can lift the ground if you have noise problems) round out the controls...
More info and photos: Vintage Revolution A-Box Live