Marc Jutras was not satisfied with the sound quality of his Hugh Tracey kalimba with pickup when it was plugged directly into his studio mixer, so he found a solution and shared it with us!
In a few months, we hope to have a similar article written by Richard Scott, who uses a high end preamp with his Hugh Tracey Kalimba plus pickup to improve sound in live performance situations.
I recently received my brand new Hugh Tracey Alto Kalimba with pickup. What a lovely instrument! After getting used to it I decided to try the pickup. I have experience with audio but not with piezo pickups. Even though I was pretty sure it wasn't the way to do it, I tried to connect it directly in my mixer inputs, both line and mic. The preamp changed nothing and in all cases, it sounded so thin and tinny it was ridiculous. I wasn't too surprised as I expected I'd have to get something else like a preamp or a direct box. The next day, I embarked on the quest for the best solution.
Note: I don't mention amplifiers because most of my work is done in studio and even if live, everything goes through a mixer.
First, I went to my usual source of info: Wikipedia. Learning what a piezo pickup is seemed mandatory to me. I looked up Pick_up_(music_technology) in Wikipedia, and there's a whole paragraph about piezoelectric pickups and preamps. My quest was starting well.
After that, my research brought me to various discussions on many sites. One of the first things I learned is that a piezoelectric pickup can sound "tinny," especially if connected directly as I had been doing. "Tinny?" You bet! Check out this article! The top section gives very important information about impedance. A piezo pickup has an output impedance of 1 megohms. Other sources mention even higher numbers.
I can't find the source in my browsing history but one manufacturer claimed that the higher the input impedance is on the preamp, the more it will be able to reproduce lower frequencies, especially the resonance of the instrument. Their preamp had a 20 megohms input impedance. Now, resonance seemed quite important to me, especially after playing my kalimba for a while. It is resonance that gives it its character and charm.
So I started hunting for a preamp, preferably FET, with a high impedance, which would also be available locally—because I wanted to try it to be sure. My search on the web led me to many different manufacturers who produce fine equipment. A discussion on a forum about acoustic guitars (search on acoustic guitars instead of kalimbas and you'll find much more stuff about piezoelectrics and preamps) recommends 4 different models and most of the forum participants supported one in particular. The Para Acoustic D.I. By L.R. Baggs is a direct box with a class A preamp and a five parameter EQ. Input impedance is rated at 10 megohms. Have a look at the product page and check the specifications for that superb piece of gear.
Using all the controls (gain, phase inversion, EQ and volume) I was able to get extremely close to the actual sound of my kalimba. I can reduce the clicking sounds produced by nails and boost bass and resonance to a point where they become way too strong. Using the FX Loop connector (a send/return), I can connect my Korg Mini Kaoss Pad before the signal reaches the EQ to have a nice mix between the original sound and the effects.
I tried it in the studio and it is indeed extremely quiet, as they claim. I still want to tweak my settings to get the absolute best sound I can get. I will also try it with some microphones to see what I can get. At about 160 US dollars, I feel it's got to be one of the best solutions out there. The sound is superb, it features many controls and possibilities, it's built like a tank and will fit in any bag. There might be better ones on the market but, for me, this one offers the best sound, control and flexibility at a decent price.
Listen to the Kalimba through the Para Acoustic DI. This is a short sample I recorded when I got my Para Acoustic D.I. My technique is not pristine yet and these are the first settings I found. It will still give you an idea of the sound you can get with it. (Recorded with a Zoom H2 digital recorder)
[Editor's note: I encourage you to go and listen to Marc's music at his web site - it doesn't yet have kalimba, but I am looking forward to seeing how kalimba will fit into his tastefully layered electronica.]