Not always the equipment that a musician uses has to be made especially for a given instrument.Sure, there are amplifiers, effects and accessories specifically desinged for guitar, bass and so forth, but often the so-called “all-purpose” equipment can be a real ace up the sleeve.A simple, and therefore very effective pre-amp like Presonus’ Tube Pre, is a fine example. I noticed its versatility when, one day, my Trace Elliot GP12 SMX bass head showed serious problems in the input jack; naturally, during the soundcheck for a concert! (As I later learned some pins that connected the input jack socket to circuit board got unsoldered and went loose). Unable to use standard instrument input I realized that I had in my suitcase the Presonus preamp (which I usually use to “warm up” the signal from the piezo upright bass pickup) and I decided to plug in with my electric bass into the preamp. From there my signal went into the effects return of the head, therefore bypassing the entire section of the Trace Elliot EQ and compressor, and going directly into the power amp section.
The result was a sound with an incredible dynamic range and broader timbre than I was used to; but then -you know- the less you process the sound with EQs, filters, etc etc, the better.
The Tube Pre is indeed a very simple tube preamp (its valve is a classic 12AX7) with only two controls, one level and a gain control. The other buttons on the front panel are just a small level attenuator (20 dB, which is useful if the input signal is already high by itself), a low-cut filter, which attenuates the frequencies below 80 Hz (needless to say, I do not use it), a reverse phase button (handy in case of feedback) and a phantom power switch, which is useful if you connect a condenser microphone, for example. A practical gauge needle shows the level of the input signal.
On the back panel there are the inputs and outputs, both balanced and unbalanced. You can therefore use the TubePre with a normal amp, plugging it in the amp’s input with a normal audio jack, and also as a DI, using the balanced output.
The transparency and dynamics of this pre-amp make it suitable for many applications, both in studio and live context, especially where the least “coloration” of your instrument’s sound is needed. I’d say that using it with an acoustic instrument is a wise choice, either with a piezo transducer, or with a microphone. Perhaps the only flaw is its peculiar voltage rating that at 16 volts makes it almost mandatory to use its proprietary transformer. In case of failure it is very difficult to find another adapter that can replace it and you’ll probably have to buy the original.
Alessandro Arcuri
