The SPL Vitalizer Mk3-T not only swaps the classic, golden robe of the previous model for the new, black design of the SPL Studio Series – the higher internal audio voltage of +/-18 V elevates this third generation SPL classic to greater sonic results and impresses with an even better and more detailed sound experience.
Drive controls the level going into the filter network. The level can be changed between -20 dB and +6 dB. In the centre position (0 dB) the level is identical to the input level.
The OVL LED indicates a potential overload of the input stages as well as internal overloads. The OVL LED lights up 3 dB before an overload. This ensures that the Vitalizer always delivers the perfect sound.
The Bass Sound control can be used to adjust between two bass sound colours.
- Soft: Moving the Bass Sound control from the centre position (0) to the left makes bass sounds soft and warm, referred to as Soft.
- Tight: If the Bass Sound control is moved from the centre position (0) to the right, this makes bass sounds dry and percussive, referred to as Tight.
The scale dots symbolize this contoured, tight bass sound and are therefore displayed in squares.
The Stereo SPL Vitalizer Mk3-T features an easy-to-use and effective “one-knob” compressor that is integrated solely into the bass processing path, leaving the original bass content untouched. Attack, Release and Threshold are pre-set. Increasing the Bass Comp value on the one hand increases the compression ratio (Ratio) and at the same time lowers the threshold value (Threshold). The compressor works with a soft knee control characteristic to sound as unobtrusive as possible. By integrating it into the bass path, the high end remains lively and airy even at strong compression rates!
The Mid-Hi Tune control of the SPL Vitalizer Mk3-T is used to set the starting frequency of a broad-band shelving filter. In line with the setting of Process control, all frequencies above this value right through to the end of the audio range are processed.
The control range is between 1.1 kHz (hard right) and 22 kHz (hard left). One of the Sovtek 12AX7 double triode tubes is used within the Mid-Hi Tune filter and gives the mid frequencies even more accurate transparency with a soft and silky sound pattern.
The Process control determines the ratio between Bass Sound and Mid-Hi Tune to the original signal and determines the attenuation intensity of dominant mid frequencies.
The LC EQ is a mid-high processing stage built around a passive coil-capacitor (LC) network. The LC-EQ creates more presence and definition in the midrange, especially for speech intelligibility and transparency. In the high frequency range, the coil convinces with extremely low noise. The frequency can be controlled between approx. 2 kHz (Low) when panned hard left stop and approx. 20 kHz (High) when panned hard right. The high frequency structure improved with the LC-EQ ensures a cleaner separation of the instrumentation and provides silky highs.
Coils are known for their pleasant sound in filter circuits. In the 60’s, coil filters were often used, later replaced by RC filters (resistor-capacitor network) due to their high pricing. Nowadays, the coil sound is desired again, especially for the mid and high frequencies, since saturating the coil produces a harmonic behaviour that is pleasant for the listening sensation. This can be compared to the difference between a tube stage and a transistor stage.
The Intensity control determines the level of the LC-EQ. As the intensity increases, the gain of the set high and mid-hi frequencies increase. At the same time, the perception time is shifted so that soft high-frequency components are not masked by loud ones. This improves speech intelligibility and clarity. The brilliance of any audio signal can be increased without sounding sharp.
The Stereo Expander increases the width of the stereo image. Working on established inter-channel phase principles, the Stereo Expander control is be used to increase the subjective soundstage width of any stereo source.
A Sovtek 12AX7 double triode tube is also used in the stereo expander. In it, the right and left channels are mixed together. The tube now adds its typical tube harmonic spectrum to the stereo signal, which consists mainly of straight harmonics.
In addition to widening the stereo image, the tube also produces a greater range of low frequencies, a clearer definition of reverb spacing and a softening of the high-frequency range, which has a very positive effect when processing digitally recorded material.
