Despite the fact that it's only half a rackspace wide, Studio Projects' VTB1 does not have what you would call a minimalist design. The variety of features in this innovative mic preamp is almost unmatched at its price point.

FIG. 1: The VTB1's almost primitiveappearance only hints at its versatility. An instrument input and mostcontrols are located on the front panel.FIG. 2: Most of the VTB1's ins and outsare located on its rear panel, along with a switch for selecting micimpedance.

Despite the fact that it's only half a rackspace wide, StudioProjects' VTB1 does not have what you would call a minimalist design.The variety of features in this innovative mic preamp is almostunmatched at its price point. The VTB1 contains a vacuum tube, but Iwouldn't call it a tube-based preamp; like many of its low-budgetcompetitors, it's a solid-state device that includes a tube to providesome interesting coloration variations. If you prefer, you can dial thetube completely out of the signal path using the front-panel Tube Blendcontrol.


Visually, the VTB1's exterior is rather unimpressive, but it feelssolid enough. Its well-built enclosure is made of steel, and the knobsand switches feel sturdily mounted. Under the hood, it features suchniceties as a ceramic tube socket, perfectly flowed solder joints,consistent length of component leads, and thick circuit boards. Likeother Studio Projects gear, the VTB1 was designed in the United Statesand built in China.

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On the unit's front panel, buttons for 48V phantom power, Line In,highpass filter (HPF), meter select (input or output), and polarityreversal (Pol Rev) are each accompanied by an LED to indicate theirstatus (see Fig. 1). A five-segment LED meter displays input andoutput levels. The Line In button selects the high-impedance instrumentinput, also on the front panel. Three conveniently detented rotary potscontrol Input Gain, Tube Blend, and Output Level.

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The VTB1's rear panel sports a 12 VAC power-supply input, an XLRbalanced out, a ¼-inch TRS line out, a ¼-inch TRS insert, aMic Impedance button, and an XLR mic in (see Fig. 2). Becausethe VTB1's rear panel provides balanced XLR and ¼-inch TRSoutputs, simultaneous output is possible, which is useful for sendingsignals to an amplifier and a mixing board at the same time, forexample.

Although the unit lacks a dedicated power switch, a blue glow (froman LED near the tube) emanates from the perforations in the front panelwhen the included wall-wart power supply is plugged in.


When I began using the VTB1, I was recording a hard-edged nu-metalproject with several synths. During the inevitable lulls in tracking, Isubstituted the Studio Projects preamp for the other preamps I wasusing, including a Peavey VMP-2, a D.A.V. Electronics BroadhurstGardens No. 1, and the onboard preamps in my Neotek IIIc console.

First up were bass guitar tracks. I favor a lightly compressed,direct-injected bass to anchor the rest of the instruments, especiallyfor dense music. The bass player and I initially used a Radial JDIdirect box feeding the Peavey preamp to record a Warmoth Geckofive-string bass. It was a great-sounding combination but too clean, sowe plugged the bass directly into the preamp's high-impedance input.That sounded quite a bit tougher, so we printed the track using thatsetup. Switching to the VTB1 yielded a similar but slightly roughersound that the bassist preferred. I found that the best method fordetermining the correct amount of tube blend was to turn up the controluntil I began to hear undesirable artifacts and then ratchet it down aclick or two.

Bass tracks in the can, the band and I moved on to synth tracks,recording a combination of Minimoog, Realistic MG-1, Chroma Polaris,and Yamaha RM1x. We used the onboard Neotek preamps to achieve thecleanest sound. The VTB1 didn't do so well on synth tracks. As I laterconfirmed with the manufacturer, using the front-panel instrument inputas a line stage is not recommended. The VTB1 can't handle a high (ormedium-high) signal level without producing some pretty massiveclipping. Still, if you want to give a track the sound of somethingabout to blow up (in a Nine Inch Nails sort of way), I encourage you totry routing line sources through the VTB1.

One of the VTB1's more innovative features is its selectableinput-impedance switch. As far as I am aware, you won't find anothermic preamp anywhere near the VTB1's price that includes this feature.However, I didn't find it especially useful. It might be effective forribbon microphones that have problems driving a high-impedance load.The control appeared to accentuate or attenuate the brightness ofmicrophones such as the Audio-Technica AT4040 and beyerdynamic M 88 TG,which is certainly a valid way to effect a tonal change withoutreaching for the EQ (or moving the microphone).

For recording vocals, I brought out the Sennheiser MD 421 — agreat choice when you're dealing with a singer who screams. Themicrophone sounded much too clean through the D.A.V. preamp and throughthe stock Neotek preamps, leaving us with a choice between the VTB1 andthe Peavey VMP-2. Not surprisingly, the VMP-2 presented a larger,smoother, more clearly defined image. Although we chose that signalpath for the lead vocal, we relied on the VTB1 for some of thebackground vocals, occasionally driving it into rampant-distortionlandby turning the Tube Blend knob most of the way up. By comparison, withthe knob turned all the way down, the VTB1 sounded rather flat anduninteresting.

Drums provided a bit more of a challenge than the VTB1 could handle,unless you're looking for tightly compacted sounds that aren'trepresentative of the source instrument. Just for fun, I recorded anextra track with a Shure 514B (a CB-radio-style, push-to-talk dynamicmicrophone) through the VTB1, with the Tube Blend turned way pastmildly distorted. We didn't end up using the track, but there wasdefinitely more than a little bit of the Tchad Blake thing going on.Forget about using the VTB1 on kick or snare; it just doesn't have theheadroom to do those instruments justice.

The general consensus among the band members was that the VTB1 isgreat for tracks that need more edge or dirt, and I agree. The VTB1 isprobably one of the last preamps I would reach for if I were recordinga string quartet, but for aggressive music (especially fornasty-sounding vocals), it's a great box.


Especially in light of its low price, the VTB1 is an intriguingproduct. It could almost be viewed as an exercise in determining howmany features you can stuff into a half-rackspace box that retails forless than $250. On the one hand, it's incapable of passing a cleansignal unscathed, but most studios already have preamps (eitherexternal or as part of a console) that are capable of that kind ofoutput.

On the other hand, the VTB1 can produce some grungy (butcontrollable and repeatable) sounds that would be difficult orimpossible to produce using a standard mic preamp. If you're in themarket for a colored preamp with attitude, and you need a unit that candouble as an excellent direct box (especially for bass guitar), theVTB1 is certainly worth an extended listen.

Richard Alan Salzis a producer, engineer, and composerliving in southern Vermont.


Studio Projects
microphone preamp



PROS: Rich in features. Interesting colorations. Versatilemetering. Very good direct injection.

CONS: No clean sounds. Tube is hard to replace.


Studio Projects
tel. (310) 373-9129

VTB1 Specifications

Amplifier Type

tube/solid-state hybrid

Tube Type



(1) balanced XLR (mic); (1) balanced ¼" TRS (line)


(1) balanced XLR; (1) balanced ¼" TRS


(1) unbalanced ¼" TRS


5-segment LED

Input Impedance

300 or 2,000ž (mic); 1.5 Mž (line)

Output Impedance

100ž XLR; 300ž TRS

Frequency Response

20 Hz-20 kHz (+0,-0.5 dB)

Maximum Preamp Gain

+60 dB mic; +30 dB line

Total Harmonic Distortion



— 20 dBu mic; 0 dBu line (at +15 dBu output)

Phase Response

<15 degrees

Highpass Filter

75 Hz, 18 dB/octave

Phantom Power


Power Supply

12 VAC wall wart


8.5" (W) × 1.5" (H) × 5.0" (D)


2.9 lb.