LeVeLAr is a single channel tube compressor/limiter designed for home recordists and small project studios. Some tube purists find ART devices to be gimmicky, but home recordists like myself find them to be immensely useful. The LeVeLAr is exceptionally simple in its user interface. You get 1/4" and balanced XLR inputs and outputs, and a few basic controls. There is not enough gain to serve as a mic preamp, but you can run an instrument directly into it. I agree with the manual, though: it works best in the inserts of a recording console or the effects loop of an amplifier. The threshold control tells the device when to start compressing or limiting your signal and the output control obviously affects the volume of the units output. A "bypass" switch allows you to turn the compression on and off but is not a "true" bypass, lending some coloration to the signal. The compress/limit switch allows you to choose a 2.3/1 or a >6/1 compression ratio. The fast/auto control allows you to choose between a 200 ms release and an "auto" 70 ms-1 second release. The LeVeLAr has a set attack time of 6.5 ms. This device can provide a heavily tube-colored compression effect, and it does this well. Like many other low-priced tube units, the LeVeLAr actually starves its tube for voltage. By doing this is it exaggerates the "tube" effect. Some pros have a lot of hostility to this sound, but to my ears it is a very useful effect. No, the LeVeLAr will not sound like a UREI 1176, but it does what it does very well. Because the controls on the unit are so simple, it allows the recordist use their ears in adjusting it for sound. Does the signal sound too squashed? Ease up on the threshold or try the other settings on the switches.. Not squashed enough? Go the other way. As an effect, the LeVeLAr can sound great on a variety of sources. I've run mic'ed and direct bass through it with great success. A fretless with EMG pickups was absolutely HUGE. I'm even more pleased with putting it in the mixer insert for a channel of mic'ed guitar to add a lot of crunch to a mic'ed guitar sound. I've had some success with the LeVeLAr on vocals, though I prefer my Really Nice Compressor (RNC) for a more transparent tone, at least to begin with. The LeVeLAr can also be used on kick drum and snare to good effect. The LeVeLAr is not a panacea. Because the LeVeLAr is not in any way transparent use it only if and when you want to hear the compression working. Its overemphasis of the tube sound can make sources sound a little blurry when used in excess. But if you're a home recordist with a limited budget, I would strongly recommend checking one of these things out. You can find one for around $50 used online, and you shouldn't pay over $80 for it new. For substantially more than the cost of two table-top units, you can also buy a stereo-linkable "Dual LeVeLAr" in a rackmount casing with internal power supply.