Quote:
Originally Posted by Dadzmad
The only downside is that you will get some signal loss. In places where I used the amp with about a 1/3 on the volume now I need to go at least 1/2 way up as an example.
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That is intentional. There are two elements to what is generally referred to as piezo quack.
The first is due to the location of the piezo UST itself which picks up a set of frequencies that tend to be dry, bright and chirpy. (Think of how the tone changes between the neck and bridge pickups on an electric guitar and go one step further from the bridge to directly under the saddle.) Too much string and too little body resonance. This is why people like to combine the under saddle tone with a mic, an SBT, or a magnetic pickup under the strings.
The second element is due to overly large transients clipping in the preamp. This is even more annoying than the above and is why high headroom preamps sound better. This can also be resolved by reducing the level of the signal being fed to the preamp. I generally find a 1nF (approx.) capacitor in parallel with the pickup does the job of halving the signal well. Some brands need more, others a bit less. The capacitor divides the signal because a piezo is primarily capacitive, and therefore won't dull the tone like it would an inductive magnetic pickup.
The quackbuster seems to achieve both of the above mitigating techniques in one device. So you get a little more body resonance added in, plus a reduction of the signal by about half.
One thing of note, and why I use a capacitor at the preamp is that the Fishman Aura pedal that I use works best with the raw (reduced level only) sound, as it adds the body resonance back in itself. The capacitor is also very easy to add to the preamp which is really at fault. That way if the preamp is changed out for a high headroom preamp, the capacitor is no longer necessary and stays with the old preamp. This also keeps the feedback resistance of a UST.