Alesis Mic Tube Anatomy
The compact rectangular brushed steel enclosure bares a slight resemblance to the infamous (and expensive) Great River ME-1NV mic preamp and houses a single 12AX7 tube driving two channels in what Alesis say is a simplified, low-noise circuit for purer signal fidelity. Each channel features a XLR/TRS ¼ inch Hi Z instrument input, balanced and unbalanced output, phase reverse, a 20dB pad, an input gain control, a drive control that dials the amount of ‘vintage tube tone’, and a nice big LED output meter. There is also a global 48v phantom power switch for powering condenser mics.
The controls are very simply laid out and the unit is very straight forward and easy to use. There is also plenty of gain on tap with more or less 65dB of clean gain including the 20dB pad. Alesis are not very forthcoming about the product specs, such as signal to noise ratios etc so how quiet it actually is remains unknown.
Apart from basic operational advice the reference material is not very informative. All promotional material for the unit claims it has an 80Hz hi-pass filter but there isn’t one to be seen anywhere on the control panel.
In trying to solve this little mystery I discovered that the single channel version, the Mic Tube Solo, has in fact got a switchable 80Hz hi-pass filter, so I speculate that the Duo was originally meant to have one but was dropped before production and the marketing department was never informed.
While tracking vocals with a condenser, the Mic Tube is reasonably quiet, with a bit of a noise floor at higher gain settings. Tonally it is fairly clean, slightly warm but overall nothing too remarkable, as should be expected in this price range.
The 12AX7 tube may just be a ‘marketing’ tube. Its influence on the sound, via the drive control, is very slight. There’s a barely noticeable roundness to mids, a boost in the extreme high frequencies and a little bit of compression, which does give a nice smooth yet immediate attack to guitars. There certainly is no sign of the advertised ‘tube overdrive‘, even when cranking the drive control. So for those wanting to liven up their synths with a bit of ‘tube voodoo’ may be a bit disappointed as the overall tonal characteristics added here are very subtle.
However, because of its simple design it may be easy to modify the Duo if you are that way inclined. For a start, replacing the 12AX7 tube with one of a higher quality may just bring some tonal enhancements. This is standard practice for some audio nuts.
The Mic Tube does however function well as a DI box, bringing unbalanced low impedance instruments up to line level. Sending a 5 string Stingray bass through it proved to be rather pleasant. The tube compression smoothes things out quite nicely as well as adds just a tiny touch of warmth in the mids and rounding out the ample lows.
The Mic Tube Duo is not intended to set the audio world alight but it does perform basic functions cleanly and quietly at a good price. As for its ‘vintage tube tone’, it does bring some very minor tonal qualities to the table.
On a shoe-string budget, the Mic Tube Duo will get the job done well enough, but in an arena of increasingly over-achieving budget audio gadgets, it may have some stiff competition soon.
I would love to see what Alesis do with the next generation.
SA Distributors: MD Musical Distributors | 021-799 4950 |
Suggested Retail Prices: Mic Tube Solo – R 1,395-00 | Mic Tube Duo – R 1,895.00