MK2 - the next generation

• Easy and intuitive handling
• Ideally suited for re-mastering stereo sources
• Inserted via master or sub-group inserts
• Excellent signal-to-noise figures
• Soft and tight bass sound with bass compressor
• Mid, high, and harmonic processing
• Variable input level
• Stereo Expander
• Hard bypass relais (power fail safety)
• Balanced operation
• XLR and stereo Jack I/Os

Concept

The Stereo Vitalizer Mk2 is the next generation of Stereo Vitalizer in which we have translated our customers' wishes and demands using our latest knowledge of the Vitalizer-filter network. The result is a totally new circuit design which adds new filters and controls to the existing parameters to fulfil the demands of the rapidly changing recording industry. It is designed for mastering, post production work and sound reinforcement.

What´s New

The signal-to-noise ratio has effectively been improved by 8 dB (at full effect), and this is especially beneficial when the Stereo Vitalizer Mk2 is wired between the mixer's output and a power amplifier, as it might be in PA or disco applications.
To set the operation level of the filter network more precisely, a Drive control has been added that enables you to set continuously variable levels between -20 dB and +6 dB. A Clip LED illuminates to indicate a potential overload. Another new feature is the integrated compressor, which only works where it is most useful: in the bass range. When recording on digital equipment, it is essential not to overload the inputs of such systems which would otherwise result in invalid samples or digital peaks. As the bass frequencies carry most of the level, it makes a lot of sense to integrate a compressor into the bass path. We designed the compressor as a 'one-knob' solution to make it easy to operate, and a soft-knee characteristic was chosen for unobtrusive operation. The threshold, attack and release are automatically adjusted while the Compression control sets the ratio value. The blue Gain Reduction LED indicates the point at which the compressor starts to operate.
The characteristic of the Process control has been changed in order to produce a mid-damping effect that sounds more consistent for the soft as well as the tight bass sound.
To freshen up the top-end of a recording, the new High EQ and Intensity controls have been integrated. The High EQ works with steep filters and controlled changes of phase relationships of the high frequencies and harmonics. The Mid-Hi Tune and the High EQ filter complement each other in an ideal fashion, while the Mid-Hi Tune sets the frequency above which the programme material is lifted and below which damping takes place.
The High EQ and Intensity controls also extract certain frequencies during this process which is very helpful when you are processing material with lead vocals: Using the Mid-Hi Tune will generally damp some speech frequencies so the voice moves into the mix losing a bit of its presence. Use the High EQ to catch the voice and the Intensity control to bring it back up front.

Connections

The Active function is a relay-switched hard-bypass, which automatically routes the input to the output in the event of a power failure to maintain signal flow.
The Stereo Vitalizer Mk2 is equipped with both XLRs & stereo jacks for balanced operation. We use the new SSM precision input & output stages which feature laser-trimmed resistors, providing a common mode rejection of better than 87 dB. Mono-jacks may be used for unbalanced operation without level change!

SPL Stereo Vitalizer Mk2 ? Add stereo magic to your mixdowns

If Sound Performance Laboratory's (SPL) new signal processor were touted merely as a sonic exciter, along the lines of similar units by Aphex, BBE and dbx, it would be a formidable rival. But the fact that it includes several more precise EQ-shaping controls and a secret weapon - the Stereo Enhancer - makes this unit virtually unbeatable, and one of the best things you can do when trying to add life and sparkle to your mixes.

The application is dirt-simple. The unit takes your master stereo signal - which can be anything from a multitrack mixdown to an old cassette to a commercially recorded CD - and gives it more brilliance, clariry, and stereo separation. The results are eye popping, improving virtually everything it touches through some psychoacoustic voodoo.

After throwing a random sampling as it - including solo acoustic guitar, hard rock, vocal accapella and symphonic music - I had to admit that virtually everything sounded more sparkly, or at least more dramatic. This made me curious - almost suspicious. How could my favorite mixes sound even better? Am I simply being fooled, as when people turn off the Dolby on Dolby-encoded tapes and mistake increased fizz for better high-end response?

The answer is yes, you are giving your ears candy when protein is available on the same plate. And there are methods you can employ to get the unit to trip over itself, and not everything will produce pleasant results. But more often than not, of you use the Stereo Vitalizer normally and judiciously, you get great results. Virtually every listener who encountered the Vitalizer (from non-musicians to engineers) agreed the effect was striking, magical.

Overview

The Stereo Vitalizer is a 1 RU device with ins and outs on the back, and knobs and switches on the front. There are no hidden configuration routines and no multi-fuction parameter knobs, making the unit very intuitive and easy to learn. Plug your cords into the back, throw on the power switch, and start tweaking. You'll hear instant results (and probably a better sound), and you'll be able to start shaping and improving your sound in about 20 seconds without even cracking the manual. The unit it best "tuned" by ear, anyway, though the manual provdes some valuable pointers.

Operation

The unit features both balanced (XLR) and unbalanced (1/4") ins and outs, You plug the stereo output of the signal (either via insert jacks or inline to another component) into and out of the Vitalizer, so that the entire signal is processed. Then, with the Active (bypass) switch you bring the unit in and out of processing mode, tweaking to taste. The front panel controls resemble other sonic exciters in that there is a separate control for the bass, but the Stereo Vitalizer goes further with ist high-frequency processors.

Moving from left to right, there's a separate control for bass boost and compression, and two controls each for the higher frequency bands (Mid-High Tune/Intensity, Hi EQ/Process). The last control is the Stereo Expander, which consists of a single control to vary the effect's intensity, and a push-button to bring it in and out. Pushing the Stereo Enhancer switch in has no effect unless the Active switch is engaged. This means that to have just the Stereo Expander feature active, you have to set the other signal processing controls (the Bass, Process and Intensity controls) to 0. This is not a limitation, as there are many situations where you would pull the Stereo Enhancer in and out, but none where you'd have the Stereo Enhancer going and kick in the other controls (that would sound like bad mixing technique).

Parameters

The EQ controls are well voiced, with their center positions reflecting typical weak spots in most mixes. The bass boost control is bi-directional. Turning the knob to the left produces a "soft" bass increase, where the bass sounds warmer and rings longer. Turning the knob to the right produces an increasingly "tight", percussive response. There's a compressor control with an LED that tells you when the threshold is crossed and gain reduction occurs. The bass response is further influenced by the Process control, which also acts on the Mid-Hi Tune controls. This Mid-Hi knob is like an intelligent broad-band shelving EQ, using an amplitude-dependent phase-shifting scheme to keep the same perception of loudness without altering the actual spectral composition of the program material (as a graphic EQ does). This is one of the Vitalizer's magical components.

The High EQ acts on specific frequencies, and as such, works in conjunction with the Mid-Hi control. Since the Mid-Hi control boosts frequencies above the center frequency and dampens those below it, some desirable frequencies (such as lead vocals), may get suppressed - sort of a throwing-the-baby-out-with-the-bathware situation. But desirable frequencies being dampened by the Mid-Hi control can be brought our with the High EQ and Process controls. Unlike conventional exciters, the High EQ works with frequencies and harmonics that exist within the program material itself, rather than creating artificial, unrelated ones (which can contribute to eat fatigue).

Applications

Processing the entire master stereo signal is the typical way you'd use the Stereo Vitalizer, but there are also other uses. Though it works best on true stereo signals, you can create a "poor man's stereo" rather easily using a mono signal and a DDL Take the direct out of, say, a guitar's mixer channel, feed it through the DDL, and come back into another mixer channel. Set the delay as follows: 100% mix, 1 repeat, 0% feedback, 1-10 ms delay time. Ordinarily, with a delay time this short, you'd get just a comb filtering effect or some phase cancellation, especially over speakers. But because the Stereo Vitalizer works on differing information between left and right channels, your two-channel signal will suddenly surge to life. Vary the delay time to increase the effect. This is one of my favorite applications for the Stereo Vitalizer. Not as wimpy as stereo chorus, but every bit as panoramic.

Sometimes the lead vocal - or anything that's panned straight up the center - diminishes in presence, and side-panned material takes on undue prominence. (This phenomena is similar to what happens in vocal eliminators, because the center-panned signal is reversed-phased and summed with the original, which cancels itself out.) So while side-panned material gains intelligibility and separation, it's sometimes at the expense of the lead vocal. However, SPL recognizes this and recommends using the High EQ and Intensity controls to help bring out these specific frequencies. But doing so birngs in more processing, which adds noise and may require "knob riding".

Noise also comes in two other forms. One is increased sibilance in some already bright vocal material. Another is simply the quiescent noise level. Pushing the Active switch in and out reveals that some fizz is being added, especially if you have the controls set high. While the unit's musicality masks most of that during strong appearance of program material, it can become a problem in fade-outs. But these are very minor caveats, consideirng that 90 percent of the time, a zestier, zingier mix is achieved with minimal tweaking.

Conclusion

There are many situations where some stereo magic is desirable, even in a "perfect" mix. Think of a demo, where you have to get poeple's jaws to drop in a short time. Or if your tape will be heard in less than optimal listening conditions, like a star stereo. And especially if you know your material will be judged under headphones, where you want increased bass and can reap the benefits of maximum separation.

If you're at play in the stereo field, you can't do without the Stereo Vitalizer. It stratifies backing instruments, gives them clarity and intellgibility, and adds exciter-like punch. For situations where something extra is neede - on demos or with old, dull, and over-copressed program material (read: your entire cassette library), a trip through the Vitalizer will provide new vitality and give you an end product that's essentially a new mix - with one push of a button.