SPL Channel One Mk3, tube preamplifier

Channel One Mk3

The perfect front-end for the modern producer

For over 20 years, Channel One has been a synonym for a high-quality and extremely musical recording and mixing channel strip.

In the newest Mk3 version, this classic has been thoroughly revised and, in addition to a higher internal audio voltage (now +/-18 V) for even better, more detailed sound, a further improved preamplifier section, an integrated Transient Designer, a Tube Saturation stage and a Mic A/B comparison option for two microphones and other great features that raise the modern recording and mixing studio to a new level of quality. With de-esser, compressor and equalizer, all the important tools of a real channel strip are still on board. Whether it’s a microphone, line, or instrument signal, the Channel One Mk3 makes any source sound like a professionally recorded signal.

The new design of the SPL Studio Series perfectly highlights the sonic qualities of this 3rd generation Channel One.

 

Comparing two microphones? No problem!

Channel One Mk3 offers two microphone inputs on the rear panel – Mic A and Mic B. Two microphones can be connected. This enormously simplifies the workflow. Thus, when comparing or changing microphones, it is no longer necessary to unplug them.
    

Preamp Out –the direct way to reach your goal

The Preamp Out picks up the signal directly after the microphone amplifier. This signal can also be recorded on a separate track in the DAW, for example, to be on the safe side. If it is noticed after a recording session that the singer was a little louder in the perfect take and therefore hits the compressor too hard, this incorrect setting can still be changed afterwards. The signal recorded for safety can later be played back into the Channel One Mk3 via the Line In and be processed there with Tube Saturation, Compressor or other tools.
    

Analog plugin

Channel One Mk3 offers the possibility to process line signals. This means that sources with line level, such as an analog signal from an audio interface, can be processed with de-esser, compressor, limiter and equalizer and then be recorded again. In this way, Channel One Mk3 becomes an “analog plugin” within an insert of a DAW.

Tube Saturation – magical tube sound

With this control the amount of tube saturation can be determined. The output level is accommodated automatically, in extreme settings the level increases by only 6 dB. Therefore decent to expressive harmonic distortions can be easily dialed in by turning just one knob.

Saturation effects are generated through the tube being pushed to and beyond its normal operating limits. In contrast to semiconductors, a tube thus pushed to such levels does not clip from a certain level, approaching more gradually its level limits and thereby producing its typical tonal result, which in audio signal processing can have such often profitable aural effects — on one hand (and depending on the amount applied), from subtle to extensive harmonic distortion and on the other hand, a compaction of the sonic event, that is, a limiting effect that exhibits a pleasant, rounded or soft sound. Acoustically and also in its range of applications this can be compared very well with tape saturation effects.

De-Esser

Unobtrusively and effectively, the Auto-Dynamic De-Esser removes distracting S‑sounds, in a mix or on vocal tracks, by detecting only the S‑frequencies, mixing them back into the main signal phase-inverted, and thus simply deleting sibilants in the original signal. The Auto-Threshold control maintains constant processing even as the singer’s distance from the microphone varies. The result is tonally neutral, unobtrusive and extremely effective. Even at high S‑reduction values, the de‑essing has no significant effect on the character and timbre of the voice.

Transient Designer – The Differential Envelope Technology

Differential Envelope Technology (DET) enables, through differential envelopes, level-independent processing of dynamic signal characteristics. Only two controls are needed to control the transient response. The envelope trackers align the working processes with the natural signal characteristics. This ensures optimum results for every moment.

Make-up Gain

The Make-Up Gain control can be used to make up for the overall level reduction caused by compression. A value between 0 dB and 20 dB can be set by which the level is increased again after compression.

With the help of the Gain Reduction display on the panel, the adjustment is very simple: if the maximum reduction value caused by the loudest part is e.g. -9 dB, the Make-Up Gain control should be set to values around +9 dB.
    

LMF

The center frequency of the half-parametric bass filter is set with the LMF control (low/mid frequencies).

The adjustable frequency range is between 30 Hz and 700 Hz so that this filter covers a range of about 4.5 octaves, allowing it to be used from the deepest bass to the lower mid range.

This together with the MHF filter ensures that the entire frequency spectrum is covered.

The -/+ control (right to the LMF control) determines the boost or cut of the LMF filter.

The maximum values are +/-12 dB. The LMF filter also operates to the proportional-Q-principle, in other words the bandwidth is dependent on the selected boost or cut. This filter characteristic permits a musically more sensible processing of the frequency spectrum than with constant-Q filters: if a more thorough setting has been chosen this will lead to far preciser definition of the frequency range to be processed. This in turn minimizes influences from adjacent ranges.
The boost or cut values, in relation to the bandwidth, lie somewhat higher than with the MHF filter. The bandwidth is therefore narrower at maximum boost than with the MHF filter for even more precise filtering. The LMF filter can be applied in many ways. Examples are; to accentuate the fundamental sound of a voice, to cut boom frequencies and for placement of bass emphasized instruments during recording or subsequently when mixing.

The VU meter

The illuminated VU meter displays the input level, output level and gain reduction. With the VU switch on the right below the VU meter it is possible to select which level is displayed.

Sounds good

With all SPL devices we develop not only according to plan, but also by ear. Many important components are installed on the circuit boards using Through-hole technology. This way we can ensure that we can use the best sounding components.